INTERNATIONAL ADVISORY COMMITTEE A. Carrington (Southampton, UK), Chair Emeritus J. M. Brown (Oxford, UK), Chair A. J. Merer (Vancouver, Canada) P. Casavecchia (Perugia, Italy) T. A. Miller (Columbus, USA) R. Colin (Brussels, Belgium) D. A. Ramsay (Ottawa, Canada) S. D. Colson (Richland, USA) F. S. Rowland (Irvine, USA) R. F. Curl (Houston, USA) T. C. Steimle (Tempe, USA) E. Hirota (Kanagawa, Japan) I. Tanaka (Tokyo, Japan) W. E. Jones (Halifax, Canada) J. J. ter Meulen (Nijmegen, Netherlands) M. Larsson (Stockholm, Sweden) B. A. Thrush (Cambridge, UK) S. Leach (Paris, France)

LOCAL ORGANIZING COMMITTEE Yuan Tseh Lee (Honorary Chairman) Kopin Liu (Honorary Cochair) Sheng-Hsien Lin (Honorary Cochair)

Yuan-Pern Lee (Chairman) Xueming Yang (Cochair) I-Chia Chen (Cochair) Bor-Chen Chang Yen-Chu Hsu Huan-Cheng Chang J.-M. Jim Lin Kuo-Mei Chen King-Chuen Lin Yit-Tsong Chen Wei-Tzou Luh Bing-Ming Cheng J.-B. Nee Po-Yuan Cheng Chi-Kung Ni Su-Yu Chiang Wen-Bih Tzeng Eric Wei-Guang Diau Chin-hui Yu Jia-Jen Ho Niann-Shiah Wang Tong-Ing Ho

SYMPOSIUM VENUE SPONSORS The Grand Hotel National Science Council, Taiwan 1, Sec. 4, Chung Shan N. Rd., Academia Sinica, Taiwan Taipei 104, Taiwan Ministry of Education, Taiwan TEL : 886-2-2886-8888 FAX : 886-2-2885-2885 National Tsing Hua University, Taiwan

Content

List of Invited Lectures 1

List of Posters 3

Abstracts of Invited Lectures 13

Abstracts of Posters 45

Poster Session A: Monday Evening 47

Poster Session B: Tuesday Evening 85

Poster Session C: Wednesday afternoon 123

Index of Authors 161

List of Invited Lectures

No. Authors and Title pp. M1 Suzuki, Toshinori 15 Chemical Dynamics Studied by Time-Resolved Photoelectron Imaging M2 Taylor, Mark; Muntean, Felician; McCoy, Anne; Barbera, Jack; Sanford, Todd; 16 Rathbone, Jeff; Andrews, Django; Lineberger, W. Carl Time Resolved Solvent Rearrangement Dynamics M3 Leone, Stephen R.; Müller, Astrid; Plenge, Jürgen; Haber, Louis; Clark, James 17 Ultrafast X-Rays: Time-Resolved Photoelectron Processes in Molecular Dissociation M4 Meijer, Gerard 18 Manipulation of Molecules with Electric Fields M5 Chou, Yung-Ching; Huang, Cheng-Liang; Ni, Chi-Kung; Kung, A. H.; Hougen, 19 Jon T.; Chen, I-Chia Rotationally Resolved Spectra of Transitions Involving Motion of the Methyl ~ Group of Acetaldehyde in the System à 1A" – X 1A' M6 Chervenkov, S.; Georgiev, S.; Siglow, K.; Braun, J.; Chakraborty, T.; Wang, P.; 20 Neusser, H. J. High Resolution Mass Selective UV Spectroscopy of Molecules and Clusters M7 Choi, Jong-Ho 21 Reaction Dynamics of Atomic Oxygen with Radicals M8 Troya, Diego; Schatz, George C. 22 Theoretical Studies of Reactions of Hyperthermal O(3P) T1 Rowland, F. Sherwood 23 in the Atmosphere T2 Akimoto, Hajime 25 Atmospheric Measurements of OH and HO2 Radicals in a Marine Boundary Layer T3 Curl, Robert F.; Han, Jiaxiang; Hu, Shuiming; Brown, John; Chen, Hongbing; 26 Thweatt, David Infrared Laser Spectroscopy and Chemical Kinetics of Free Radicals T4 Zhu, R. S.; Xu, Z. F.; Lin, M. C. 27 Ab Initio Studies of Free Radical Reactions of Interest to Atmospheric Chemistry T5 Pollack, Ilana B.; Konen, Ian M.; Li, Eunice X. J.; Lester, Marsha I. 28 Significant OH Radical Reactions in the Atmosphere: A New View

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W1 Balaj, O. Petru; Balteanu, Iulia; Beyer, M. K.; Bondybey, Vladimir E. 29 Free Electrons: The Simplest Free Radicals of them All W2 Merkt, Frédéric 30 High-Resolution Photoelectron Spectroscopic Studies of Ions and Radicals W3 Vilesov, Andrey F. 31 Helium Droplets as a Unique Nano-Matrix for Molecules and Molecular Aggregates W4 Bonhommeau, D.; Viel, A.; Halberstadt, N. 32 Non-adiabatic Dynamics of Ionized Neon Clusters inside Helium Nanodroplets W5 Momose, Takamasa 33 Free Radicals in Quantum Crystals: A Study of Tunneling Chemical Reactions R1 Zhou, Jingang; Shiu, W.; Zhang, B.; Lin, Jim J.; Liu, Kopin 34 From Pair Correlation to Reactive Resonance in Polyatomic Reactions R2 Skodje, Rex T. 35 State-to-State-to-State Dynamics of Chemical Reactions: The Control of Detailed Collision Dynamics by Quantized Bottleneck States R3 Brouard, Mark 36 The Stereodynamics of Photon-Initiated Reactions R4 Aoiz, F. J.; Bañares, L.; Barr, J.; Torres, I.; Pino, G. A.; Amaral, G. A. 37 Photodissociation Dynamics of Polyatomic Molecules Containing Sulfur: An Experimental Study R5 Ni, Chi-Kung 38 Photodissociation of Simple Aromatic Molecules Studied by Multimass Ion Imaging Techniques F1 Kerenskaya, Galina; Schnupf, Udo; Heaven, Michael C. 39 Spectroscopy and Dynamics of NH Radical Complexes F2 Hutson, Jeremy M.; Soldán, Pavel 40 Molecules in Cold Atomic Gases: How do They Interact? F3 Steimle, Timothy C. 41 Optical Stark and Zeeman Spectroscopy of Transition Metal Containing Radicals F4 Hsu, Yen-Chu 42 + The Bending Vibrational Levels of C3-Rare-Gas Atom Complexes and C2H2 F5 Maier, John P. 43 Electronic Spectra of Carbon Chains and their Relevance to Astrophysics

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List of Posters Monday Evening, 26 July, 2004

No. Authors and Title pp. A1-01 Laperle, Christopher M.; Mann, Jennifer E.; Continetti, Robert E. 47

Three-Body Dissociation Dynamics of the Low-Lying Rydberg States of H3 A1-02 Lin, Jim J.; Perri, Mark J.; Van Wyngarden, Annalise L.; Boering, Kristie A.; 48 Lee, Yuan T. Reaction Dynamics of Isotope Exchange Reaction of Singlet Oxygen Atom with Carbon Dioxide Molecule: A Crossed Molecular Beam Study A1-03 Tseng, Chien-Ming; Dyakov, Yuri A.; Huang, Cheng-Liang; Mebel, Alexander 49 M.; Lin, Sheng Hsien; Lee, Yuan T.; Ni, Chi-Kung Photoisomerization and Photodissociation of Aniline and 4-Methylpyridine A1-04 Zhou, Weidong; Yuan, Yan; Zhang, Jingsong 50 H-atom Elimination of n-Propyl and iso-Propyl Radicals: A Photodissociation Study A1-05 Lee, Shih-Huang; Lee, Yuan T. 51 Studies of Photodissociation Dynamics Using Selective Photoionization A1-06 Zhang, Bailin; Shiu, Weicheng; Lin, Jim J.; Liu, Kopin 52 0 0 Imaging the Mode-Correlation of Product Pairs: OH + CD4 → CD3 (00 Q, 22 Q) + HOD(ν1 ν2 0) A1-07 Dyakov, Yuri A.; Mebel, Alexander M.; Lin, S. H.; Lee, Yuan T.; Ni, Chi-Kung 53 Photodissociation of 4-Picoline, Aniline and Pyridine: Ab Initio and RRKM Study A1-08 Lee, Yin-Yu; Dung, Tzan-Yi; Lee, Shih-Huang; Pan, Wan-Chun; Chen, I-Chia; 54 Lin, Jr-Min; Yang, Xueming; Lee, Yuan T.

Isomeric Species CH2SH and CH3S Formation from Photodissociation of Methanethiol at 157 nm A1-09 Wu, Chia-Yan; Wu, Yu-Jong; Lee, Yuan-Pern 55

Photodissociation of Fluorobenzene (C6H5F) at 193 nm Monitored with Time-resolved Fourier-transform Infrared Emission Spectroscopy A1-10 Chen, Wei-Kan; Ho, Jr-Wei; Cheng, Po-Yuan 56

Ultrafast Photodissociation Dynamics of Acetone S2 State at 195 nm A1-11 Castillo, J. F.; Aoiz, F. J.; Banares, L.; Vazquez, S.; Martinez-Nuñéz, E.; 57 Fernandez-Ramos, A.

Quasiclassical Trajectory Studies of the F + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

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A1-12 Eskola, Arkke; Seetula, Jorma; Timonen, Raimo 58 Kinetics of the Reactions of Methyl Radical with HCl and DCl at Temperatures 188 – 500 K: Tunneling A1-13 Tseng, S. Y.; Huang, C. L.; Wang, T. Y.; Wang, N. S.; Xu, Z. F.; Lin, M. C. 59 Kinetics of the NCN + NO Reaction A1-14 Wu, Di; Wang, Bing-Qiang; Li, Zhi-Ru; Hao, Xi-Yun; Li, Ru-Jiao; Sun, 60 Chia-Chung

Single-electron Bonds in the Methyl Radical Complexes H3C⋅⋅⋅HF and H3C⋅⋅⋅HCCH: an ab initio Study A1-15 Hela, P. G.; Shih, H.-T.; Cheng, C.-H.; Chen, I-C. 61 Dynamics of Photoluminescence in Bistriphenylene A1-16 Chang, Chih-Wei; Diau, Eric Wei-Guang; Chang, I-Jy 62

Ultrafast Interfacial Electron Transfer Dynamics of the TiO2 Nanostructures Functionalized by the Ru2+ Complexes A1-17 Hancock, G.; Morrison, M.; Saunders, M. 63 Time Resolved FTIR Emission Studies of Molecular Dynamics A2-01 Katoh, Kaoru; Sumiyoshi, Yoshihiro; Ueno, Taketoshi; Endo, Yasuki 64 Fourier-Transform Microwave Spectroscopy of CCCl and CCCCCl A2-02 Kobayashi, Kaori; Saito, Shuji 65 Isotope Study of the CCO Radical in its 3Σ- Ground State by Microwave Spectroscopy A2-03 Lin, Chia-Shih; Chang, Wei-Zhong; Hsu, Hui-Ju; Chang, Bor-Chen 66 New Dispersed Fluorescence Spectra of Simple Halocarbenes in a Discharge Supersonic Free Jet Expansion A2-04 Radi, Peter P.; Tulej, Marek; Knopp, Gregor; Beaud, Paul; Gerber, Thomas 67

Double-Resonance Spectroscopy on HCO and H2CO by Two-Color Resonant Four-Wave Mixing A2-05 Fink, E. H.; Ramsay, D. A. 68

Near Infrared Emission Spectra of HO2 and DO2 A2-06 Evertsen, R.; Staicu, A.; van Oijen, J. A.; Dam, N. J.; de Goey, L. P. H.; 69 ter Meulen, J. J.

Cavity Ring Down Spectroscopy of CH, CH2, HCO and H2CO in a Premixed Flat Flame at both Atmospheric and Sub-atmospheric Pressure A2-07 Yurchenko, Sergei N.; Carvajal, Miguel; Jensen, Per; Lin, Hai; Thiel, Walter 70

Rotation-vibration Motion of Pyramidal XY3 Molecules Described in the Eckart Frame: Theory and Application to NH3 A2-08 Chen, Kuo-mei 71

Resonance-enhanced Multiphoton Ionization Spectroscopy of CH3 and CD3. Two-photon Absorption Selection Rules and Rotational Line Strengths of the v3- and v4-Active Vibronic Transitions

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A2-09 Shayesteh, Alireza; Appadoo, Dominique R. T.; Gordon, Iouli; Bernath, Peter F. 72

The Vibration-Rotation Emission Spectra of Gaseous ZnH2 and ZnD2 A2-10 Balfour, Walter J.; Brown, John M.; Wallace, Lloyd 73 Identification and Characterization of Two New Electronic Transitions of the FeH Radical in the Infrared A2-11 Ashworth, Stephen H.; Varberg, Thomas D.; Hodges, Philip J.; Brown, John M. 74

Detection of the Electronic Spectra of FeCl2 and CoCl2 in the Gas Phase A2-12 Merer, A. J.; Peers, J. R. D.; Rixon, S. J. 75 Free Radicals in the Reaction Products of Zr with Methane: the Electronic Spectra of ZrC and ZrCH A2-13 Tang, Sheunn-Jiun; Chou, Yung-Ching; Lin, Jim Jer-Min; Hsu, Yen-Chu 76 The Bending Vibrational Levels of Acetylene Cation: A Case Study of the Renner-Teller Effects with Two Degenerate Bending Vibrations A2-14 Yoshida, K.; Kanamori, H. 77 High Resolution Spectroscopic Studies of Vibrational States in the Triplet Potential of Acetylene A2-15 Lin, I-Feng; Kurniawan, Fendi; Chiang, Su-Yu 78

Experimental and Theoretical Studies on Rydberg States of H2CS in the Region 130-220 nm A2-16 Jacox, Marilyn E.; Thompson, Warren E. 79

Infrared Spectra of Neutral and Ionic SO2H2 Species Trapped in Solid Neon A2-17 Jochnowitz, Evan B.; Zhang, Xu; Nimlos, Mark R.; Varne, Mychel Elizabeth; 80 Stanton, John F.; Ellison, G. Barney Polarized IR Spectrum of Matrix-Isolated Propargyl Radicals and Detection of HC≡CH-CH2OO A2-18 Cardenas, R.; Bates, S. A.; Robbins, D. L.; Rittby, C. M. L.; Graham, W. R. M. 81 Recent Progress in FTIR and DFT Studies on the Vibrational Spectra and Structures of Group IV Clusters A2-19 Delaney, Cailin; Clar, Justin; Cohen, Jodi; Abrash, Samuel A. 82 Photochemistry of HI-Allene Complexes in Argon Matrices A2-20 van de Meerakker, S. Y. T.; Vanhaecke, N.; Meijer, G. 83 Decelerating OH and NH Radical Beams A2-21 Hu, Shui-Ming; Liu, An-Wen; He, Sheng-Gui; Zheng, Jing-Jing; Lin, Hai; Zhu, 84 Qing-Shi Inter-bonds Crossing Dipole Moment and Stretching Vibrational Bands Intersities of the Group V Hydrides

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Tuesday Evening, 27 July, 2004

No. Authors and Title pp. B1-01 Capozza, G.; Leonori, F.; Segoloni, E.; Balucani, N.; Stranges, D.; Volpi, G. G.; 85 Casavecchia, P. 3 Crossed Molecular Beam Studies of Radical-radical Reactions: O( P) + C3H5 (Allyl) B1-02 Balucani, N.; Capozza, G.; Segoloni, E.; Cartechini, L.; Bobbenkamp, R.; 86 Casavecchia, P.; Bañares, L.; Aoiz, F. J.; Honvault, P.; Bussery-Honvault, B.; Launay, J.-M. The Dynamics of Prototype Insertion Reactions: Crossed Beam Experiments versus Quantum and Quasiclassical Trajectory Scattering Calculations on Ab 1 2 Initio Potential Energy Surfaces for C( D) + H2 and N( D) + H2 B1-03 Lin, Ming-Fu; Dyakov, Yuri A.; Lin, Sheng-Hsien; Lee, Yuan T.; Ni, Chi-Kung 87

Photodissociation Dynamics of Pyridine and C6HxF6-x (x = 1~4) at 193 nm B1-04 Zhou, Weidong; Yuan, Yan; Zhang, Jingsong 88 State-to-state Photodissociation Dynamics of OH Radical via the A2Σ+ State and 3 Fine-structure Distributions of the O( PJ) Product B1-05 McCunn, L. R.; Miller, J. L.; Krisch, M. J.; Liu, Y.; Butler, L. J.; Shu, J. 89 Molecular Beam Studies of the Photolysis of 2-Chloro-2-butene and the Subsequent Dissociation of the 2-Buten-2-yl Radical B1-06 Shiu, Vincent W. C.; Lin, Jim J.; Liu, Kopin; Wu, Malcom; Parker, David H. 90 Threshold is More Exciting: Seeing Reactive Resonance in a Polyatomic Reaction B1-07 Martínez-Núñez, Emilio; Marques, Jorge M. C.; Vázquez, Saulo A. 91 Dissociation of the Methanethiol Radical Cation Induced by Collisions with Ar Atoms: An Investigation by Quasiclassical Trajectories B1-08 Obernhuber, Thorsten; Kensy, Uwe; Dick, Bernhard 92 The Photodissociation Dynamics of t-Butylnitrite Initiated by Excitation to the S2 Electronic State B1-09 Yang, Sheng-Kai; Chen, Hui-Fen; Liu, Suet-Yi; Wu, Chia-Yan; Lee, Yuan-Pern 93 Photolysis of 2-Fluorotoluene at 193 nm: Internal Energy of HF Determined with Time-resolved Fourier-transform Infrared Emission Spectroscopy B1-10 Cireasa, D. R.; Moise, A.; ter Meulen, J. J. 94 Inelastic State-to-state Scattering of Oriented OH by HCl B1-11 Castillo, J. F.; Aoiz, F. J.; Banares, L. 95

Quasiclassical Trajectory Studies of the Cl + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

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B1-12 Pimentel, André S.; Nesbitt, Fred L.; Payne, Walter A.; Cody, Regina J. 96

Planetary Chemistry of C2H5 Radicals: Rate Constant for the CH3 + C2H5 Reaction at Low Temperatures and Pressures B1-13 Chou, Sheng-Lung; Lee, Yuan-Pern; Lin, Ming-Chang 97 3 Experimental Studies of the Rate Coefficients of the Reaction O( P) + CH3OH at High Temperatures B1-14 Li, Zhi-Ru; Wu, Di; Li, Ru-Jiao; Hao, Xi-Yun; Wang, Bing-Qiang; Sun, 98 Chia-Chung

Electron Donor-Acceptor Bonds in the Methyl Radical Complexes H3C-BH3, H3C-AlH3 and H3C-BF3: an ab initio Study B1-15 Liu, Kuan Lin; Cheng, Chao Han; Tang, Kuo-Chun; Chen, I-Chia 99 Rapid Intersystem Crossing in Highly Phosphorescent Iridium Complexes B1-16 Luo, Liyang; Chiang, Chia-Chen; Diau, Eric Wei-Guang; Lin, Ching-Yao 100

Ultrafast Electron Transfer and Energy Transfer Dynamics of Porphyrin- TiO2 Nanostructures B1-17 Yin, Hong-Ming; Sun, Ju-Long; Cong, Shu-Lin; Han, Ke-Li; He, Guo-Zhong 101

The Internal Energy Distribution and Alignment Properties of the CH3O (X) Fragment by the Photodissociation of CH3ONO at 355 nm B2-01 Suma, Kohsuke; Sumiyoshi, Yoshihiro; Endo, Yasuki 102 Fourier-transform Microwave Spectroscopy and FTMW-millimeter-wave Double Resonance Spectroscopy of XOO (X = Cl, Br) Radicals B2-02 Han, Huei-Lin; Chu, Li-Kang; Lee, Yuan-Pern 103 Detection of Infrared Absorption of Gaseous ClCS Using Time-resolved Fourier-transform Spectroscopy B2-03 Fan, Haiyan; Ionescu, Ionela; Annesley, Chris; Xin, Ju; Reid, Scott A. 104 On the Renner-Teller Effect and Barriers to Linearity and Dissociation in HCF(Ã1 A") B2-04 Colin, Reginald; Liu, Ching-Ping; Lee, Yuan-Pern 105 Detection of Predissociated Levels of the SO B 3Σ- State using Degenerate Four-wave Mixing Spectroscopy B2-05 Elliott, N. L.; Fitzpatrick, J. A. J.; Chekhlov, O. V.; Ashworth, S. H.; Western, C. 106 M. Electronic Structure from High Resolution Spectroscopy B2-06 Dagdigian, Paul J.; Nizamov, Boris; Teslja, Alexey 107

Cavity Ring-Down Spectroscopy of Polyatomic Transient Intermediates: H2CN and H2CNH B2-07 Pollack, Ilana B.; Konen, Ian M.; Li, Eunice X. J.; Lester, Marsha I. 108 Significant OH Radical Reactions in the Atmosphere: A New View

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B2-08 Muramoto, Yasuhiko; Ishikawa, Haruki; Mikami, Naohiko 109 ~ 1 First Observation of the B ( A1) State of SiH2 and SiD2 Radicals by the OODR Spectroscopy B2-09 Bernath, P.; Bauschlicher, C. W.; Dulick, M.; Ram, R. S.; Burrows, A. 110 Metal Hydrides in Astronomy B2-10 O'Brien, Leah C.; Hardimon, Sarah 111 Fourier Transform Spectroscopy of Gold Oxide, AuO B2-11 Balfour, Walter J.; Li, Runhua; Jensen, Roy H.; Shephard, Scott A.; Adam, Allan 112 G. The First Observation of the Rhodium Monofluoride Molecule Jet-cooled Laser Spectroscopic Studies B2-12 Miller, Terry A. 113 Spectroscopy of Free Radicals in Hydrocarbon Oxidation B2-13 Chou, Yung-Ching; Chen, I-Chia; Hougen, Jon T. 114 Anomalous Splittings of Torsional Sublevels Induced by the Aldehyde Inversion Motion in the S1 State of Acetaldehyde B2-14 Lee, P. C.; Yang, J. C.; Nee, J. B. 115

Absorption Spectra of O2 and NO in 105-200 nm Wavelength Region Measured by using a Supersonic Jet B2-15 Willitsch, Stefan; Innocenti, Fabrizio; Dyke, John M.; Merkt, Frédéric 116 Rovibronic Energy Level Structure of the Two Lowest Electronic States of the Ozone Cation B2-16 Lo, Wen-Jui; Chen, Hui-Fen; Chou, Po-Han; Lee, Yuan-Pern 117

Isomers of OCS2: IR Absorption Spectra of OSCS in Solid Argon B2-17 Zhang, Xu; Kato, Shuji; Bierbaum, Veronica M.; Ellison, G. Barney 118 Gas-Phase Reactions of Organic Radicals and Diradicals with Ions B2-18 Larsson, M.; McCall, B. J.; Huneycutt, A. J.; Saykally, R. J.; Geballe, T. R.; 119 Djurić, N.; Dunn, G. H.; Semaniak, J.; Novotny, O.; Al-Khalili, A.; Ehlerding, A.; Hellberg, F.; Kalhouri, S.; Neau, A.; Paál, A.; Thomas, R.; Österdahl, F. + H3 Dissociative Recombination and the Cosmic-Ray Ionisation Rate towards ζ Persei B2-19 Oguchi, T.; Hattori, T.; Matsui, H. 120 The Reaction Mechanism of O(1D) with Ethylene: the Product Yield Measurements of OH, CH2CHO and H atom B2-20 Geppert, W. D.; Thomas, R.; Ehlerding, A.; Hellberg, F.; Österdahl, F.; Millar, T. 121 J.; Semaniak, J.; af Ugglas, M.; Djuric, N.; Larsson, M. Dissociative Recombination of Astrophysically Important Isoelectronic Ions B2-21 Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Ahmed, Musahid; 122 Neumark, Daniel M. Photoelectron Spectroscopy of Nitric Oxide Doped in Helium Droplets

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Wednesday Afternoon, 28 July, 2004

No. Authors and Title pp. C1-01 Capozza, G.; Leonori, F.; Segoloni, E.; Volpi, G. G.; Casavecchia, P. 123 3 Dynamics of HCCO and CH2 Radical Formation from the Reaction O( P) + C2H2 in Crossed Beams using Soft Electron Impact Ionization for Product Detection C1-02 Capozza, G.; Segoloni, E.; Volpi, G. G.; Casavecchia, P. 124 Towards the "Universal" Product Detection in Crossed Beam Reactive Scattering Experiments using Soft Electron Impact Ionization: Dynamics of Vynoxy, Acetyl, Methyl, Formyl, and Methylene Radicals and Ketene Formation 3 from the Reaction O( P) + C2H4 C1-03 Liu, Chen-Lin; Hsu, Hsu Chen; Ni, Chi-Kung 125 + Photodissociation of I2 Studied by Velocity Map Imaging C1-04 Higashiyama, Tomohiko; Ishida, Masayuki; Honma, Kenji 126 2 3 − 2 3 Dynamics of Reaction, Y( D3/2, 5/2) + O2(X Σ g) → YO(A Π) + O( PJ), Studied by Crossed Beam-chemiluminescence Technique C1-05 Miller, J. L.; McCunn, L. R.; Krisch, M. J.; Butler, L. J.; Shu, J. 127 Molecular Beam Studies of the Dissociation and Isomerization of Radical Isomers: The Influence of the Electronic Wavefunction in the Dissociation Dynamics of Vinoxy Radicals C1-06 Chang, Chushuan; Luo, Chu-Yung; Liu, Kopin 128 Mode- and State-selected Photodissociation of OCS+ by Time-sliced Velocity Mapping Image Technique C1-07 Martínez-Núñez, Emilio; Vázquez, Saulo A. 129

Quasiclassical Trajectory Study of the 193 nm Photodissociation of CF2CHCl C1-08 Fujimura, Yo; Tamada, Hisashi; Imai, Yoshiyuki; Mitsutani, Kazuya; Kajimoto, 130 Okitsugu 1 Reinvestigation of O( D)+H2O Reaction: Examination of the Contribution of Excited States C1-09 Bahou, Mohammed; Lee, Yuan-Pern 131 Photodissociation Dynamics Investigated with a Pulsed Slit-jet and Time-resolved Fourier-transform Spectroscopy C1-10 Lee, Sheng-Jui; Chen, I-Chia 132 Ab Initio Studies for Dissociation Pathway and Isomerization of Crotonaldehyde C1-11 Ho, Jr-Wei; Yang, Chia-Ming; Lai, Ta-Jen; Cheng, Po-Yuan 133 The Use of Ultrafast Photodissociation as a Probe for Studies of Electronic Energy Transfer Dynamics

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C1-12 Oum, Kawon; Sekiguchi, Kentaro; Luther, Klaus 134 The Role of Radical-Molecule Complexes in the Recombination Kinetics of Benzyl Radicals C1-13 Alam, M. S.; Rao, B. S. M.; Janata, E. 135 Reactions of •OH and H• with Aliphatic Alcohols: A Pulse Radiolysis Study C1-14 Cheng, Mu-Jeng; Chu, San-Yan 136

Substituent Effect on Structure and Bonding of Bertrand Diradical (X2P)2(BY)2 C1-15 Guss, Joseph; Kable, Scott 137

Characterisation of the CCl2 Ã State C1-16 Kumae, Takashi; Arakawa, Hatsuko 138 Assessment of Training Effects on Levels of Serum Total Anti-oxidative Activity in Matured Rats using Luminol-dependent Chemiluminescence C1-17 Dong, Feng; Whitney, Erin; Zolot, Alex; Deskevich, Mike; Nesbitt, David J. 139 High Resolution Spectroscopy and Reaction Dynamics of Free Radicals C2-01 Katoh, Kaoru; Sumiyoshi, Yoshihiro; Endo, Yasuki; Hirota, Eizi 140

FTMW and FTMW-MMW Double Resonance Spectroscopy of the CH3OO Radical C2-02 Juances-Marcos, Juan Carlos; Althorpe, Stuart C. 141 Geometric Phase and the Hydrogen-Exchange Reaction C2-03 Fan, Haiyan; Ionescu, Ionela; Annesley, Chris; Xin, Ju; Reid, Scott A. 142 Polarization Quantum Beat Spectroscopy of HCF(Ã1A"): 19F and 1H Hyperfine Structure, Zeeman Effect, and Singlet-triplet Interactions C2-04 Liu, Ching-Ping; Reid, Scott A.; Lee, Yuan-Pern 143 Two-color Resonant Four-wave Mixing Spectroscopy of Highly Predissociated 2 Levels in the à A1 State of CH3S C2-05 Ahmed, K.; Balint-Kurti, G. G.; Western, C. M. 144

Exploring the Potential Energy Surfaces of C3 C2-06 Zhang, Guiqiu; Chen, Kan-Sen; Merer, Anthony J.; Hsu, Yen-Chu; Chen, 145 Wei-Jan; Sadasivan, Shaji; Liao, Yean-An; Kung, A. H. 1 Perturbations in the à Πu, 000 Level of C3 C2-07 Marshall, Mark D.; Greenslade, Margaret E.; Davey, James B.; Lester, Marsha 146 I. Partial Quenching of Orbital Angular Momentum in the OH-Acetylene Complex C2-08 Fujii, Asuka; Miyazaki, Mitsuhiko; Ebata, Takayuki; Mikami, Naohiko 147 Infrared Spectroscopy of Large-sized Protonated Water Cluster Cations: Development of the 3-Dimensional Hydrogen Bond Network with Cluster Size C2-09 Luh, Wei-Tzou 148 Electronically-excited Singlet States of LiH C2-10 O'Brien, Leah C.; O'Brien, James J. 149 Intracavity Laser Spectroscopy of NiH

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C2-11 Jakubek, Zygmunt J.; Nakhate, Sanjay; Simard, Benoit; Zachwieja, Mirek 150

Spectroscopy of Si+NH3 and Si-PH3 Reaction Products: Rovibronic Structure of the Ground Electronic States of SiNSi and PH2 C2-12 Varberg, Thomas D.; Le Roy, Robert J. 151 Isotope Dependence and Born-Oppenheimer Breakdown in Mid- and Far-Infrared Spectra of Hydride C2-13 Baek, Dae Youl; Wang, Jinguo; Doi, Atsushi; Kasahara, Shunji; Baba, Masaaki; 152 Katô, Hajime Doppler-free Two-photon Excitation Spectroscopy and the Zeeman Effect of the 1 1 1 1 10 140 Band of the S1 B2u←S0 A1g Transition of Benzene-d6 C2-14 Huang, Cheng-Liang; Liu, Chen-Lin; Ni, Chi-Kung; Hougen, Jon T. 153

Electronic Spectra of Molecules with Two C3v Internal Rotors: Torsional 1 1 Analysis of the A Au – X Ag LIF Spectrum of Biacetyl C2-15 Willitsch, Stefan; Dyke, John M.; Merkt, Frédéric 154

Rotationally Resolved Photoelectron Spectrum of NH2 and ND2: Rovibrational ~ + 1 ~ + 3 Energy Level Structure of the a A1 and X B1 States C2-16 Wu, Yu-Jong; Chou, Chun-Pang; Lee, Yuan-Pern 155

Isomers of CNO2: Infrared Absorption of ONCO in Solid Neon C2-17 Chou, Chun-Pang; Wu, Yu-Jong; Lee, Yuan-Pern 156

IR Spectroscopy of Ge(NO) and Ge(NO)2 Isolated in Solid Argon C2-18 Ehlerding, A.; Geppert, W.; Zhaunerchyk, V.; Hellberg, F.; Thomas, R.; Arnold, 157 S. T.; Viggiano, A. A.; Semaniak, J.; Österdahl, F.; af Ugglas, M.; Larsson, M. Dissociative Recombination of Hydrocarbon Ions C2-19 Thomas, R. D.; Ehlerding, A.; Geppert, W.; Hellberg, F.; Larsson, M.; Rosen, S.; 158 Zhaunerchyk, V.; Bahati, E.; Bannister, M. E.; Vane, C. R.; Petrignani, A.; van der Zande, W. J.; Andersson, P.; Pettersson, J. B. C. The Effect of Bonding on the Fragmentation of Small Systems C2-20 Hu, Qichi; Hepburn, John 159 Dynamics and Spectroscopy of Threshold Photoion-Pair Formation C2-21 Chen, Chun-Cing; Wu, Hsing-Chen; Tseng, Chien-Ming; Yang, Yi-Han; Chen, 160 Yit-Tsong; One- and Two-photon Excitation Vibronic Spectra of 2-methylallyl Radical at 4.6-5.6 V

11

12

Abstracts of Invited Lectures

13

14

M1

Chemical Dynamics Studied by Time-Resolved Photoelectron Imaging

Toshinori Suzuki Chemical Dynamics Laboratory, Discovery Research Institute RIKEN (Institute of Physical and Chemical Research) Wako, Saitama 351-0198, JAPAN

As the Born-Oppenheimer approximation indicates, chemical change is driven by electrons. Observation of rapid changes of electronic state or electron configuration during the course of chemical reaction will be essential for elucidating the dynamics. In the last decade, solid-state ultrafast laser technology has been well established to allow various types of pump-probe experiments of chemical reactions; however, further efforts seemed to be necessary to directly observe electronic dynamics. We have combined femtosecond pump-probe ionization method with two-dimensional imaging of photoelectron scattering distribution to observe electronic dephasing processes in real-time. In addition to the electronic dynamics, vibrational, and rotational wavepacket motions vary the kinetic energy and ejection angle of photoelectrons, which makes time-resolved photoelectron imaging to be a powerful tool for studying chemical dynamics. In this talk, we will present the method, some recent results, problems, and future possibilities.

“Non-adiabatic dynamics effects in Chemistry revealed by time-resolved charged particle imaging”, T.

Suzuki and B.J. Whitaker, Int. Rev. Phys. Chem. 20, 313 (2001).

“Time-resolved photoelectron spectroscopy and imaging”, T. Suzuki in Modern Trends in Chemical

Reaction Dynamics, Advanced Series in Physical Chemistry, (World Scientific, 2004).

15

M2

Time Resolved Solvent Rearrangement Dynamics

Mark Taylor1, Felician Muntean1, Anne McCoy2, Jack Barbera, Todd Sanford, Jeff Rathbone, Django Andrews, and W. Carl Lineberger1 1JILA and Department of Chemistry and Biochemistry, Boulder, CO, USA 1JILA Visiting Fellow, 2003; Permanent Address, Ohio State University, Columbus, OH, USA

A femtosecond negative ion-neutral-positive ion charge reversal apparatus is employed to investigate transient neutral species evolving along a reaction coordinate. We report studies of the rearrangement dynamics of Cu(OH2) and Cu(OH2)2 produced by photodetachment of the corresponding anion. Negative ion photoelectron imaging spectroscopy is employed to characterize the initial anion. Following a controlled delay period, a second ultrafast tunable laser pulse (photon energy close to that of the Cu 2P excited state) initiates resonant multiphoton photoionization of the time-evolving Cu···OH2 complex.

+ + The time-resolved Cu and Cu (OH2) signals provide information both on the prompt dissociation of the complex and on the slower (10s of ps) energy redistribution between internal rotational and radial modes of the evolving complex. Calculations of the time evolution of the anion geometric configuration on the neutral potential energy surface yield deeper insight into the nature of the rearrangement process and the energy flow within the complex. Recent studies on other partially solvated systems will be briefly discussed.

Supported by NSF and AFOSR

16

M3

Ultrafast X-Rays: Time-Resolved Photoelectron Processes in Molecular Dissociation

Stephen R. Leone, Astrid Müller, Jürgen Plenge, Louis Haber, and James Clark Departments of Chemistry and Physics and Lawrence Berkeley National Laboratory University of California, Berkeley, CA 94720 USA [email protected] http://chem.berkeley.edu/people/faculty/leone/leone.html

Radical chemistry and production are investigated by ultrafast time-resolved photoelectron spectroscopy. High-order harmonics of a Ti:sapphire laser are produced in the vacuum ultraviolet or soft x-ray spectral region to serve as the probe pulses for valence shell and core level photoelectron spectra of transient and dissociating species. Soft x-ray femtosecond pulses are generated by focusing intense 800 nm pulses into a rare gas pulsed jet of Ar or Ne, producing the probe photons at every odd harmonic of 800 nm with energies up to 100 eV. Photofragmentation dynamics of small molecules is initiated with visible or ultraviolet pulses from the same master laser system. Two types of time-resolved photoelectron spectroscopies, x-ray photoelectron (XPS) and valence band photoelectron (PES), probe between different potential surfaces of the molecules. Diatomic molecules, such as bromine, are excited to a repulsive dissociative state or a bound electronic state, and selected harmonics are used to obtain time-resolved photoelectron spectra. The resulting bromine atom radicals are detected as they are produced in real time, and these signals are related to the timescale for the free atomic species to be formed. The wave packet amplitude on the dissociative state is observed and related to the above threshold ionization processes in the molecule, which occur simultaneously. Relative ionization cross sections are determined as a function of probe wavelength. New experiments emphasize dissociation and intramolecular processes in polyatomic molecule systems. Results are presented for the production and characterization of the harmonics, including spectral bandwidth determinations, temporal resolution, and the use of the harmonics for stable-molecule and dissociating-state core level and valence shell photoelectron spectroscopy. Related high resolution studies of molecules and radicals are performed at the Chemical Dynamics Beamline of the Advanced Light Source. A recirculating-linac-based concept for ultrafast x-ray pump-probe science is being developed, and the potential for studies with this possible future facility are also discussed.

17

M4

Manipulation of Molecules with Electric Fields

Gerard Meijer

Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany and FOM Institute for Plasmaphysics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands

During the last years we have been experimentally exploring the possibilities of manipulating neutral polar molecules with electric fields [1]. Arrays of time-varying, inhomogeneous electric fields have been used to reduce in a stepwise fashion the forward velocity of molecules in a beam. With this so-called 'Stark decelerator', the equivalent of a LINear ACcelerator (LINAC) for charged particles, one can transfer the high phase-space density that is present in the moving frame of a pulsed molecular beam to a reference frame at any desired velocity; molecular beams with a computer-controlled (calibrated) velocity and with a narrow velocity distribution, corresponding to sub-mK longitudinal temperatures, can be produced. These decelerated beams offer new possibilities for collision studies, for instance, and enable spectroscopic studies with an improved spectral resolution; first proof-of-principle high-resolution spectroscopic studies have been performed. These decelerated beams have also been used to load neutral ammonia molecules in an electrostatic trap at a density of (better than) 107 mol/cm3 and at temperatures of around 25 mK. In another experiment, a decelerated beam of ammonia molecules is injected in an electrostatic storage ring. The package of molecules in the ring can be observed for more than 50 distinct round trips, corresponding to 40 meter in circular orbit and almost 0.5 sec. storage time, sufficiently long for a first investigation of its transversal motion in the ring. A scaled up version of the Stark-decelerator and molecular beam machine has just become operational, and has been used to produce decelerated beams of ground-state OH and electronically excited (metastable) NH radicals. The NH radical is particularly interesting, as an optical pumping scheme enables the accumulation of decelerated bunches of slow NH molecules, either in a magnetic or in an optical trap. By miniaturizing the electrode geometries, high electric fields can be produced using only modest voltages. A micro-structured mirror for neutral molecules that can rapidly be switched on and off has been constructed and used to retro-reflect a beam of ammonia molecules with a forward velocity of about 30 m/s. This holds great promise for miniaturizing the whole decelerator, trap and storage ring for future applications.

References [1] H.L. Bethlem and G. Meijer, Int. Rev. Phys. Chem. 22, 73 (2003)

18

M5

Rotationally Resolved Spectra of Transitions Involving Motion of the ~ ~ Methyl Group of Acetaldehyde in the System A 1A″− X 1A′

Yung-Ching Chou,1 Cheng-Liang Huang,1 Chi-Kung Ni2, A. H. Kung2, Jon T. Hougen3, and I-Chia Chen1 1Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013, 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106 3Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8441

~ ~ Fluorescence excitation spectra, at resolution 0.02 cm-1, in the system A 1A″− X 1A′ were recorded for acetaldehyde in a supersonic jet. We performed full rotational analysis of

0+ n 0− n 0+ 0- bands 140 150 and 140 150 , for n = 0 – 5, in which 14 and 14 denote the two inversion tunneling components of the aldehyde hydrogen out of plane bending, in the vibrational ~ ground state of A 1A″. Torsional levels from the lowest energy to beyond the methyl torsional barrier up to 370 cm-1 are assigned. These high energy states lying above the torsional barrier display character between the limits of torsional vibrational motion and free internal rotor motion, so that the close-lying 5A2 and 6A1 states mix for K > 0, and K states in the E sublevel are widely split. Anomalous transitions (∆Ka = 0, ∆Kc = 0) to A sublevels are

0+ 4 0− 3 0- n observed for bands 140 150 and 140 150 . The positions of A and E sublevels in 14 15 cannot be fitted with a program involving only interaction of torsion and rotation, furthermore for n = 0–1 states the A/E splitting is reversed from those in 140+15n.

Interaction with inversion evidently varies the splitting of torsional sublevels and the K structure.

19

M6

High Resolution Mass Selective UV Spectroscopy of Molecules and Clusters

S. Chervenkov, S. Georgiev, K. Siglow, J. Braun, T. Chakraborty, P. Wang, and H. J. Neusser

Physikalische und Theoretische Chemie, Technische Universität München, Lichtenbergstr. 4, D-85748 Garching, Germany

Rotationally resolved UV spectra of molecular clusters in the gas phase have been measured with 100 MHz resolution and mass selection in a resonance-enhanced two-photon ionization process [1]. Analyzing the complex rotational structure of the vibronic bands of hydrogen-bonded clusters of aromatic molecules with water we have found information on the water position and the intermolecular vibrational dynamics. Results are presented for water complexes of benzonitrile, indole, and 4-fluorostyrene. Recently the technique has been successfully applied to flexible molecules of biological importance: the neurotransmitters ephedrine [2] and 2-phenylethanol. To better understand the conformational dynamics and the role of the intramolecular hydrogen bonds for the conformational stability we performed ab initio calculations. Combining pulsed high resolution and pulsed field ionization techniques we were able to resolve individual high Rydberg states (45 < n < 110) for the first time in a polyatomic molecule, benzene, and its van der Waals complexes with Ne, Ar, and Kr [1]. The series limits represent the individual rotational states of the respective radical cation yielding structural information on the van der Waals distance of the noble gas atom and on spin orbit coupling in the benzene radical cation induced by the external heavy noble gas atom. Mass analyzed pulsed field threshold ionization (MATI) of bunches of very high Rydberg states is a powerful method for vibrational spectroscopy of radical cations and their production with defined internal energy. The mass selectivity allows us to detect with high precision the dissociation threshold of van der Waals bound aromatic radical cations with noble gases [3-5] and of hydrogen-bonded aromatic molecule-water complexes 3-methylindole-water and –benzene [6]. The ionization of the complex leads to strengthening of the hydrogen bond by factor of three caused by the additional charge.

[1] H. J. Neusser, K. Siglow, Chem. Rev. 100, 3921 (2000). [2] S. Chervenkov, P. Q. Wang, J. E. Braun, H. J. Neusser, submitted to J. Chem. Phys. [3] H. Krause, H. J. Neusser, J. Chem. Phys. 97, 5923 (1992). [4] J. E. Braun, H. J. Neusser, Mass Spectrom. Rev. 21, 16 (2002) [5] S. Georgiev, T. Chakraborty, H. J. Neusser, J. Phys. Chem. 108, 3304 (2004) [6] S. Georgiev, H. J. Neusser, Chem. Phys. Letters 189, 24 (2004)

20

M7

Reaction Dynamics of Atomic Oxygen with Hydrocarbon Radicals

Jong-Ho Choi

Department of Chemistry, Korea University, Seoul 136-701, Korea

3 The reaction dynamics of ground-state atomic oxygen (O( P)) with propargyl (C3H3) radicals have first been investigated by applying laser induced fluorescence (LIF) spectroscopy in a crossed beam configuration. New exothermic channels (1) and (2) were observed, and the nascent internal state distributions of some products showed substantial bimodal internal excitations.

3 O( P) + C3H3 → C3H2 + OH (1)

→ C3H2O + H (2) We also performed ab initio, RRKM (Rice-Ramsperger-Kassel-Marcus) and prior calculations to characterize the reaction mechanism and energy partitioning. It has been found out that the surprising difference in the potential energy surfaces for the two reactions plays a critical role in understanding the reaction mechanisms. We hope this work sheds some light on the gas-phase atom-radical dynamics at the molecular level, which has been very little explored so far.

[1] H.C. Kwon, J.H. Park, H. Lee, H.K. Kim, Y.S. Choi, and J.H. Choi*, J. Chem. Phys. (Communications) 116. 2675 (2002). [2] J.H. Park, H. Lee, H.C. Kwon, H.K. Kim, Y.S. Choi, and J.H. Choi*, J. Chem. Phys. 117. 2017 (2002). [3] J.H. Park, H. Lee, Y.S. Choi, and J.H. Choi*, J. Chem. Phys. 119, 8966 (2003).[4]. H. Lee, S.K. Joo, L.K. Kwon, J.H. Park, Y.S. Choi, and J.H. Choi*, J. Chem. Phys. (Communications) 119, 9337 (2003).[5] H. Lee, S.K. Joo, L.K. Kwon, and J.H. Choi*, J. Chem. Phys. 120, 2215 (2004). [6] S.K. Joo, L.K. Kwon, H. Lee, and J.H. Choi*, J. Chem. Phys. 120, 7976 (2004).

21

M8

Theoretical Studies of Reactions of Hyperthermal O(3P)

Diego Troya and George C. Schatz

Department of Chemistry, Northwestern University, Evanston, IL 60208-3113 USA

Recently, Tim Minton at Montana State has performed a series of crossed molecular beam experiments involving the reaction of hyperthermal oxygen atoms (several eV energies) with H2, methane, ethane, propane and with polymer surfaces. These experiments are of importance as they relate to the interaction of O(3P) found in low earth orbit with the polymer-containing surfaces of space craft. This talk will describe a series of computational simulations designed to model these reactions. The calculations are based on direct dynamics calculations in which the MSINDO semiempirical electronic structure method is used to determine forces for each time step in classical molecular dynamics simulations. For our gas/surface simulations we also use QM/MM (quantum mechanics/molecular mechanics) calculations in which the portions of the polymer that are close to the O atom are treated as quantum atoms and the rest are described with molecular mechanics. We have calibrated the quality of the MSINDO potential surface through extensive calibration with higher quality ab initio calculations. Although hydrogen abstraction to give OH plus an alkyl radical is the expected product for O + reactions, our hyperthermal results show that collision energies above 2 eV lead to new reaction pathways, including addition of the O atom with H elimination to produce alkoxy radicals, direct C-C bond breakage, direct water formation as well as aldehyde formation. In certain cases we have been able to determine the importance of excited state potential surfaces in the dynamics, as well as intersystem crossing effects. Collision induced dissociation can play a role in some cases, and we have been able to show how angular distributions for certain reactions switch from backward to forward peaked as collision energy is increased.

22

T1

Hydrocarbons in the Atmosphere

F. Sherwood Rowland Departments of Chemistry and Earth System Science University of California Irvine, California, 92697, U.S.A.

The local presence of hydrocarbons in the atmosphere has been known for about two centuries, with identification of specific compounds beginning about a century ago. However, the first confirmation that methane is present everywhere in the troposphere is generally attributed to Migeotte's spectroscopic measurements in 1948. Quantitative measurements of the simultaneous atmospheric presence of O3 and O2 demonstrate that the molar ratio is about 10-6, far in excess of a calculated thermodynamic equilibrium between them of 10-30. Similarly, the calculated thermodynamic equilibrium concentration of methane in the presence -140 of O2 and H2O should be 10 times that of carbon dioxide. The atmosphere is thus far from equilibrium, in the former case because of the constant influx of solar radiation, and in the latter because many of the minor components such as methane are present in detectable amounts only because of ongoing emissions from biological sources. The reactive removal of volatile hydrocarbons from the atmosphere is primarily the consequence of attack by hydroxyl radicals, which are formed by ultraviolet attack on tropospheric ozone in (1) with the formation of O(1D) atoms which react with water vapor, as in (2). Hydroxyl radicals can attack saturated hydrocarbons by abstracting H in (3), and the residual R radical immediately adds an O2 molecule to form RO2 in (4). formation is favored O3 + hυ → O(1D) + O2 (1) O(1D) + H2O → 2 HO (2) HO + RH → H2O + R (3) R + O2 → RO2 (4) in the summer because of more hours of more intense sunlight, and in the tropics by higher humidity which favors (3) in competition with deexcitation by collisions with N2 or O2. The average atmospheric lifetime for a molecule I whose primary sink is reaction with HO can be approximately estimated from its measured laboratory reaction rate k3i versus k3 for a compound of known atmospheric lifetime. With a measured lifetime for anthropogenic methylchloroform, CH3CCl3, of five years, the have estimated lifetimes of 8 years for methane, 2 months for ethane, 2 weeks for propane, and a few hours for ethylene. Because the rate of north/south mixing of the atmosphere is approximately 15 months, methane is the only simple hydrocarbon which survives long enough to provide substantial contributions in both northern and southern hemispheres before being oxidized by HO radicals. For molecules such as ethane and propane, a strong seasonal variation is observed in the temperate and polar latitudes with minimum concentrations in the summer. Because most hydrocarbons enter the atmosphere in the north, the concentrations there are much very much higher than in the south. We began collecting atmospheric samples in remote locations on both sides of the equator in 1978. Our measurements of methane in 1979 showed slightly higher concentrations than in 1978, indicating that its global concentration was rising. Continuation of this series of measurements have shown an increase from a global average of 1.52 ppmv in 1978 to 1.78 ppmv in 2003. Observations of methane from ice cores by other research groups show a gradual increase toward present levels from 0.75 ppmv at the beginning of the industrial revolution two centuries ago. The warming of the atmosphere by accumulation of

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anthropogenic gases was expanded in the 1970s from a "carbon dioxide problem" to a "greenhouse gas problem", with the experimental observation of significant increases over time of methane, nitrous oxide, the chlorofluorocarbons (CFCs), and tropospheric ozone as additional contributors to the trapping of outgoing infrared radiation. Water vapor is actually the major absorber of outgoing infrared radiation, but its atmospheric concentration responds to the temperature of the world's oceans, and increases as the Earth warms. With the assumption that all of the infrared radiation emitted by the Earth escapes to space, a simple calculation of the required average temperature for the Earth to emit enough infrared radiation to balance the incoming solar energy gives a temperature of −18°C. With an average Earth temperature of +14°C, this leads to a calculation of +32°C for the natural greenhouse effect. The calculation of a projected temperature increase of 1.4°C to 5.8 °C during the 21st century is the estimate of the incremental temperature increase which will accrue with the increases in global atmospheric concentrations of carbon dioxide, methane, nitrous oxide, CFCs, tropospheric ozone, water vapor and in various aerosols. The RO2 radicals from (4) can react with NO in reaction (5) to form NO2, and its subsequent photolysis produces O atoms and then ozone. A very minor product of reaction (5) leads to the formation of alkyl nitrates, RONO2, which therefore become a marker for the production of ozone from the main channel of (5) + (6). We have investigated the hydrocarbon composition of the air RO2 + NO → RO + NO2 (5) NO2 + hυ → NO + O →→ O 3 (6) in many cities around the world, and have observed not only the importance of vehicular traffic for the release of reactive hydrocarbons and nitrogen oxides, but also the importance of liquefied petroleum gas (typically C3 and C4 alkanes) in creation of urban ozone through reactions (4) to (6). We have also measured very high concentrations of alkane hydrocarbons in the rural southwest United States as the consequence of hydrocarbon leakage from the oil and gas industries. These alkanes have been accompanied by elevated alkyl nitrates, demonstrating that enough NO is present in these to trigger ozone formation even in these non-urban environments. We have also participated in numerous aircraft- and ship-based experiments which have led to other observations of hydrocarbons and their reactions. These include: (1) their formation by biomass burning, as measured both on the ground and in plumes thousands of miles from the location of the burning; (2) removal by chlorine atom reaction in the near-absence of tropospheric ozone at altitudes below 500 feet above frozen Hudson Bay (Canada); and (3) increased production of isoprene and alkanes accompanying CO2 decreases during "iron fertilization" experiments in the Southern Ocean. All of these experiments have been performed in collaboration with Professor Donald R. Blake and various members of our research group, and with support from NASA and/or DOE, NSF, NASDA (Japan) and the Comer Foundation.

24

T2

Atmospheric Measurements of OH and HO2 Radicals in a Marine Boundary Layer

Hajime Akimoto Atmospheric Composition Research Program Frontier Research System for Global Change, Yokohama, Japan [email protected]

The OH and HO2 radicals are the most important players of atmospheric reactions since they are the key carriers of chain reactions of tropospheric photochemistry. Therefore, the comparison between the observed and model-calculated concentrations of OH/HO2 radicals can provide the most direct validation of tropospheric photochemical theory. Due to the very low concentration of OH radicals (the order of 106 radicals/cm3 or less), however, reliable measurement of these radicals has long been delayed since the pioneering attempt in 1970s. Development of new technology enabled reliable measurement of these radicals on the ground as well as in the aircraft since the middle of 1990’s. Since then three techniques has been practically used in the ambient atmospheric application; laser-induced fluorescence(LIF), differential optical absorption spectroscopy (DOAS), and chemical ionization mass spectrometry (CIMS). We developed a laser-induced fluorescence instrument and successfully implemented it in field campaigns at three remote islands of Japan (Oki, Okinawa and Rishiri Island). At Cape

Hedo of Okinawa Island, the observed daytime level of HO2 agreed closely well with the model-calculated results constraint to observed concentrations of NOx, hydrocarbonds, aldehydes, CO, etc. which control “fast photochemistry” to generate and destroy HOx radicals. This fact suggests that the photochemistry at Cape Hedo, Okinawa is well described by the current mechanism.

In contrast, at Rishiri Island, the observed daytime concentration of HO2 was consistently much lower than the model-calculated values in both 2000 and 2003 campaigns. Possible processes that reduced the daytime HO2 are studied here, with the possibilities of (1) heterogeneous loss of HO2 on aerosol surfaces, (2) unexpectedly fast HO2+RO2 reactions, and

(3) possible role of iodine chemistry. Analysis of simultaneous measurements of OH and HO2 radicals provides further discussion of unknown factors of atmospheric photochemistry.

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T3

Infrared Laser Spectroscopy and Chemical Kinetics of Free Radicals

Robert F. Curl, Jiaxiang Han, Shuiming Hu, John Brown, Hongbing Chen, & David Thweatt Department of Chemistry, Rice Quantum Institute, Rice University, Houston, TX 77005

Our research has two aims: the observation and analysis of the infrared spectra of free radicals and the investigation of their chemical kinetics. The degenerate CH stretching fundamental of CH3O is our current interest. The upper state of the degenerate CH stretch should consist of four subsystems corresponding to the four possible choices of the signs of l and Σ relative to Λ. Significant progress has been made on this spectrum. Two sets of subsystems have been observed in the jet-cooled spectrum and J values assigned to the lines of their p-labeled component subbands. In addition, several apparently isolated subbands have been assigned to p and J values. However, it is not clear at this time whether both of the two assigned subsystems belong to the degenerate CH stretch even though they clearly have perpendicular rotational selection rules. The spectra observed and our efforts to make sense of them will be described. The infrared kinetic spectroscopy method is also used to explore radical kinetics. A specific system of current interest is the determination of the product

1 yields of reactions of O( D) with CH4. We have discovered significant hot atom effects even at buffer gas (He) pressures above 10 Torr.

26

T4

Ab Initio Studies of Free Radical Reactions of Interest to Atmospheric Chemistry

R. S. Zhu, Z. F. Xu and M. C. Lin Department of Chemistry, Emory University Atlanta, GA 30322, USA

Free radical reactions involving HOx, NOx, SOx and ClOx play their pivotal roles in various aspects of atmospheric chemistry from acid rains to O3-formation in the troposphere and O3-destruction in the stratosphere. Until recently prediction of their reaction rates and product-branching ratios over a wide range of P,T-conditions had been difficult and unreliable.

Recent progress made in energy prediction by means of practically reliable computational methods and rate constant calculations for barrierless radical-radical association processes by solution of energy- and pressure-dependent master equation coupling all accessible quantum states of multiple reactive intermediates allows us to estimate rate constants and product-branching ratios to within kinetic accuracy. Several examples studied in our laboratory on reactions of some of the aforementioned radicals will be discussed.

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T5

Significant OH Radical Reactions in the Atmosphere: A New View

Ilana B. Pollack, Ian M. Konen, Eunice X. J. Li, and Marsha I. Lester Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323 USA

The three-body OH + NO2 + M → HONO2 + M association reaction is of fundamental importance in atmospheric chemistry because it is an important sink of reactive HOx and NOx radicals that directly affect the ozone budgets of the troposphere and stratosphere. Until very recently, HONO2 was believed to be the only product of the OH + NO2 reaction. However, a surprisingly large discrepancy between OH kinetic loss measurements performed at high and low pressures has lead several groups to suggest that peroxynitrous acid (HOONO), a less stable isomer of HONO2, may be a secondary product of this reaction and the coupled HO2 + NO reaction. Recently, this laboratory produced HOONO by reaction of photolytically generated

OH and NO2 radicals, stabilized the intermediate in a pulsed supersonic expansion, and identified the trans-perp (tp) conformer of HOONO through infrared action spectroscopy in the OH overtone region.[1] Extensive rotational band structure associated with the OH overtone transition yields structural parameters and its transition dipole moment, which are in good accord with ab initio values. The infrared overtone excitation provides sufficient energy to break the O-O bond of tp-HOONO, producing OH (v=0) fragments that are detected. The internal energy distribution of the OH fragments is consistent with a prior distribution, and enables an accurate determination of the HOONO binding energy. The spectroscopically derived value is in good accord with recent theoretical results and a kinetic estimate of its stability. Comparisons will be made with previous infrared studies of HOONO conformers isolated in Ar matrices [2] and more recent studies in a discharge flow tube.[3,4] Many issues concerning the formation, isomerization, dissociation, and yield of HOONO under jet-cooled and atmospheric conditions will be discussed in the oral and poster presentations.

[1] I. B. Pollack, I. M. Konen, E. X. J. Li, and M. I. Lester, J. Chem. Phys. 119, 9981 (2003). [2] B. M. Cheng, J. W. Lee, and Y. P. Lee, J. Phys. Chem. 95, 2814 (1991); W.-J. Lo and Y. P. Lee, J. Chem. Phys. 101, 5494 (1994). [3] S. A. Nizkorodov and P. O. Wennberg, J. Phys. Chem. A 106, 855 (2002). [4] B. D. Bean, A. K. Mollner, S. Nizkorodov, G. Nair, M. Okumura, S. P. Sander, K. A. Peterson, and J. S. Francisco, J. Phys. Chem. A 107, 6974 (2003).

28

W1

Free Electrons: The Simplest Free Radicals of them All

O. Petru Balaj1, Iulia Balteanu1, M. K. Beyer1 and Vladimir E. Bondybey1,2, 1Institute für Physicalishe Chemie, Technische Universität München, Garching 2Department of Chemistry, University of California, Irvine

Free radicals are usually defined as highly reactive species with unpaired electrons. Electrons themselves are highly reactive and unpaired and can therefore be considered to be the simplest free radicals. In the almost two hundred years since Humphrey Davy first noted the blue color appearing when sodium is dissolved in ammonia, free electrons in solutions have been extensively studied. More recently it was shown, that solvated gas phase electrons1 can also be generated, and we have found that a laser vaporization source developed in our laboratory with supersonic expansion, produces very cleanly hydrated ! electron clusters e (H2O)n with n − 12-100 for studies by Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry. Even in the absence of collisions the trapped clusters gradually disappear due to heating by the black body infrared background radiation, and interesting size dependent competition between the loss of and electron detachment. The finite clusters with exactly known composition are a very convenient medium for electron reaction studies, since unlike bulk solution “pulsed electrolysis” experiments they are not plagued by the effects of minor impurities. We will discus and describe here briefly the rich, multifaceted chemistry of the electron clusters, whose reactions can be crudely classified into several categories: a) Many simple, nonpolar molecules and atoms just contribute to cluster fragmentation b) Polar molecules capable of forming strong, hydrogen bonded networks can be exchanged for the water ligands, and gradually replace part or even all of the aqueous shell

c) Reactions with species such as O2 or CO2, which can attach the free electron forming an anion stabilized strongly by hydration, result in replacement of the ionic core of the cluster. d) With a number of species, for instance acetonitrile or HCl, a true “chemistry” is observed, where existing covalent bonds are broken and/or new ones formed.

1. M. Armbruster, H. Haberland, and H. G. Schindler, Phys. Rev. Lett. 47, 323 (1981) 2. M. K. Beyer, B. S. Fox, B. M. Reinhard and V. E. Bondybey, J. Chem. Phys. 115, 9288 (2001)

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W2

High-Resolution Photoelectron Spectroscopic Studies of Ions and Radicals

Frédéric Merkt ETH Zürich, Physical Chemistry, CH-8093 Zürich, Switzerland

Photoelectron spectroscopy (PES) represents a useful tool to study the photoionization dynamics of molecules and to study the properties of molecular radicals and ions. In the past years progress has been made that enables the recording of VUV PE spectra at high resolution using several variants of the technique of pulsed-field-ionization zero-kinetic energy (PFI-ZEKE) PES. In our experiments, we record such spectra by monitoring the field ionization of very high Rydberg states (n > 150) located below each ionization threshold as a function of the wavenumber of a narrow bandwidth VUV laser. In a first variant, carefully designed electric field pulse sequences are used to achieve a high selectivity in the field ionization process and to record PE spectra at a resolution of 0.06 cm-1 [1]. A second variant, called Rydberg-state-resolved threshold ionization can be used to resolve the high Rydberg states within each line in a PFI-ZEKE PE spectrum, enabling one to record photoelectron spectra at a resolution limited by the bandwidth of the laser radiation used (in our case 250 MHz) [2]. Finally, millimeter wave spectroscopy can be used to record transitions between high Rydberg states at sub MHZ resolution [3]. Our studies have enabled us to resolve the complete rotational structure and in several cases the spin-rotational fine structure and even the hyperfine structure in the PE spectra of molecules. A new source of cold radicals in supersonic expansions has been developed that is compatible with the high-vacuum requirement of our PFI-ZEKE PE spectrometers and which can be used to study a wide range of radicals [4]. The talk will present a survey of these developments and illustrate them by PE spectroscopic measurements carried out on hydride radicals such as NH2, CH2 and C2H5 and on reactive molecules such as O3. [1] U. Hollenstein, R. Seiler, H. Schmutz, M. Andrist, and F. Merkt, J. Chem. Phys. 114, 9840 (2001). [2] R. Seiler, U. Hollenstein, G. M. Greetham, and F. Merkt, Chem. Phys. Lett. 346, 201 (2001). [3] A. Osterwalder and F. Merkt, Int. Rev. Phys. Chem. 21, 385-403 (2002). [4] S. Willitsch, J.M. Dyke, and F. Merkt, Helv. Chim. Acta 86, 1152-1166 (2003).

30

W3

Helium Droplets as a Unique Nano-Matrix for Molecules and Molecular Aggregates

Andrey F. Vilesov Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA

In this talk experiments on spectroscopy of molecules and molecular complexes in helium droplets will be reviewed. Some recent developments include the introduction of pulsed droplet beams and the application of pulsed infrared lasers to molecular spectroscopy in droplets. The study of the phthalocyanine (Pc), Mg-Pc and Zn-Pc molecules in helium droplets is reported. The electronic spectra in the vicinity of the band origins show low energy vibronic bands. These bands correspond to vibrational modes of several helium atoms localized by molecular interaction. In other experiments we used large helium droplets of 105 – 107 atoms as hosts to assemble molecular clusters. The rotationally resolved spectra of the ν1 and ν3 vibrational modes of (NH3)n clusters and the ν3 mode of

3 (CH4)n (n = 1 – 2x10 ) clusters in He droplets have been obtained. The quenching of the molecular rotational motion and the development of the vibrational bands of molecular clusters upon an increase in cluster size are studied.

31

W4

Non-adiabatic Dynamics of Ionized Neon Clusters inside Helium Nanodroplets

D. Bonhommeau, A. Viel, and N. Halberstadt LPQ-IRSAMC, CNRS and University Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France

One of the most common experimental tools to study host molecules or clusters inside helium nanodroplets is mass spectrometry, which implies an ionization step. This ionization usually produces fragmentation of the host molecule or cluster. The purpose of this work is to determine the role of the helium environment in the dissociation. Is there no effect since these nanodroplets have been shown to be superfluid, or is any dissociation inhibited because of the very high heat conductivity of superfluid helium? Ionized rare gas clusters constitute ideal model systems to study these fragmentation processes. Ionization brings the cluster from the neutral configuration with bond lengths typical of Van der Waals bonding to the ionic surfaces where the equilibrium bond lengths are much shorter. The cluster ion is thus produced in a configuration containing a large amount of internal energy and dissociates. Experiments by Janda and coworkers [1] have shown that their fragmentation is significantly hindered, and can even be caged, in helium nanodroplets. We have set up a simulation [2] of the ionization-dissociation process of these rare gas clusters in a helium nanodroplet, using the molecular dynamics with quantum transitions (MDQT) method [3] to treat the inherently multi-surface nature of the dynamics. The electronic part is evolved quantum-mechanically, while the coordinates of the atoms are propagated classically, with hops between adiabatic surfaces allowed. The potential energy surfaces are described in the diatomics in molecules (DIM) model. The helium environment is described by an ad hoc model, using a friction force acting on atoms with velocities above the Landau critical velocity. A reasonable range of values for the corresponding friction coefficient is obtained by comparison with existing experimental measurements.

[1] B.E. Callicoatt, K. F¨orde, T. Ruchti, L. Jung, and K.C. Janda, J. Chem. Phys. 108, 9371 (1998). [2] D. Bonhommeau, A. Viel and N. Halberstadt, J. Chem. Phys., in press. [3] J.C. Tully, J. Chem. Phys. 93, 1061 (1990).

32

W5

Free Radicals in Quantum Crystals: A Study of Tunneling Chemical Reactions

Takamasa Momose Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan e-mail: [email protected]

Solid parahydrogen is a unique matrix for the study of chemical reactions of cold molecules.[1,2] By virtue of the softness of solid parahydrogen as a quantum crystal, rotational motion of molecules in the crystal is well quantized as in the gas phase. Moreover, molecules are mobile in the crystal, so that various chemical reactions occur in the crystal. As a result, quantitative information on chemical reactions of nearly free molecules at liquid He temperatures such as tunneling chemical reactions can be obtained directly from the spectroscopy of molecules in solid parahydrogen. In the present work, tunneling chemical reactions between deuterated methyl radicals and the hydrogen molecule in a parahydrogen crystal have been studied by FTIR spectroscopy. The tunneling rates of the reactions R + H2 → RH + H (R=CD3, CD2H, CHD2, and CH3) in the vibrational ground state were determined directly from the temporal change in the intensity of the rovibrational absorption bands of the reactants and products in each reaction in solid parahydrogen observed at 5 K. The tunneling rate of each reaction was found to differ definitely depending upon the degree of deuteration in the methyl radicals. The tunneling rates thus determined were 3.3 ×10-6 s-1, 2.0×10-6 s-1, and 1.0 ×10-6 s-1 for the systems of CD3, CD2H, and CHD2, respectively. Conversely, the tunneling reaction between a CH3 radical and the hydrogen molecule did not proceed within a week's time. The upper -8 -1 limit of the tunneling rate of the reaction of the CH3 radical was estimated to be 8×10 s . The tunneling reaction rates are clearly faster for heavier isotopomers in these systems. The "anomalous" deuteration effect will be discussed.

1. T. Momose, and T. Shida, Bull. Chem. Soc. Jpn, 71, 1 (1998). 2. T. Momose, H. Hoshina, M. Fushitani, and H. Katsuki, Vib. Spectrosc. 34, 95 (2004). 3. T. Momose, H. Hoshina, N. Sogoshi, H. Katsuki, T. Wakabayashi, and T. Shida, J. Chem. Phys. 108, 7334 (1998). 4. H. Hoshina, M. Fushitani, T. Momose, and T. Shida, J. Chem. Phys. 120, 3706 (2004).

33

R1

From Pair Correlation to Reactive Resonance in Polyatomic Reactions

Jingang Zhou, W. Shiu, B. Zhang, Jim J. Lin, and Kopin Liu Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan 106

A novel time-sliced velocity imaging technique has been developed and implemented in crossed-beam scattering experiments. Using this new approach, a number of atoms/radicals with methane, such as F, Cl, OH + CH4 etc., and its isotopic variants were investigated. What revealed from these studies is the coincident information of the state-resolved pair-correlation of the two products. The correlated state distributions and differential cross sections show striking differences for various product pairs, which open a new way to unravel the complexity of a typical polyatomic reaction.

In this talk, we will elucidate the concept of product pair correlation and highlight some of the major findings. In addition, we will show how such kind of measurements leads to the discovery of a reactive resonance in six-atom reactions of F + CH4 and F + CHD3.

34

R2

State-to-State-to-State Dynamics of Chemical Reactions: The Control of Detailed Collision Dynamics by Quantized Bottleneck States * (i-iii)

Rex T. Skodje1,2

1) Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan and 2) Department of Chemistry, University of Colorado

It has long been realized that the characteristics of the transition state of a chemical reaction control the reaction rate constant. More recently, Truhlar and coworkers have established that quantized bottleneck states (QBS), which lie at the maxima of adiabatic potential curves, provide a basis to understand the energy dependence of the cumulative reaction probability.

In this presentation, we discuss new work that reveals that the control exerted by the QBS extends even to highly detailed state-to-state differential cross sections of elementary reactions. Using various isotopes of the H+H2 prototype reaction, we show how the angular dependence and product distribution of the reactions can be rationalized in terms of the properties of the QBS. The understanding of the (initial) state-to (transition) state-to

(final) state reaction dynamics not only provides a basis to observe the QBS, but also adds predictive power to the study of reaction dynamics.

* This work was done in collaboration with SD Chao, M. Gustafsson, and the experimental group of XM Yang. i) S. A. Harich et al, Nature, 419, 281 (2002). ii) D. X. Dai, et al, Science, 300, 1730 (2003). iii) S. A. Harich, et al, J. Chem. Phys., 117, 8341 (2002).

35

R3

The Stereodynamics of Photon-Initiated Reactions

Mark Brouard* The Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom

Laser pump-probe techniques have been used to study the stereodynamics of photon initiated unimolecular and bimolecular processes. The experiments employ polarized photolysis radiation coupled with either laser-induced fluorescence (LIF) or resonantly enhanced multiphoton ionisation (REMPI) and velocity-map ion-imaging. Using the latter technique, 3 we have recently characterized the O( PJ) photofragments generated in the photodissociation of N2O at 193nm:

3 N2O + hv Æ N2 + O( PJ)

The dependence of the ion-images, and integrated image intensities, on laser pump-probe polarization geometry has enabled us to determine the electronic alignment of the ground state O-atom photofragments [1]. The data have been used to help identify the electronic channel responsible for spin-forbidden dissociation in this atmospherically important molecular system.

Our studies of bimolecular processes are of the photon-initiated type [2], as illustrated by the example

HX + hv Æ H + X 2 H + H2O Æ OH( ΠΩ)+ H2

These measurements provide a route not just to product quantum state population distributions, but also to kinetic energy release distributions, which provide information about scalar pair correlations between the internal excitation in the probed fragment (OH in the above example) and the co-product (H2), to angular scattering distributions (a two vector (k,k’) correlation proportional to the differential cross-section), and angular momentum polarization distributions (a (k,k’,j’) three vector correlation proportional to the polarization dependent differential cross-sections). Examples will be provided from both our LIF and ion-imaging work.

[1] M. Brouard, A.P. Clark, C. Vallance, O.S. Vasyutinskii, J. Chem. Phys. 119, 771, (2003). [2] M. Brouard, P. O'Keeffe, C. Vallance, J. Phys. Chem. A, 106, 3629, (2002).

* email address: [email protected]

36

R4

Photodissociation Dynamics of Polyatomic Molecules Containing Sulfur: An Experimental Study

F. J..Aoiz 1, L. Bañares, J. Barr, I. Torres, G. A. Pino, G. A. Amaral Departamento de Química Física I. Facultad de Química. Universidad Complutense de Madrid. 28040 Madrid. Spain

The photodissociation of the deuterated dimethyl sulfide, CD3SCD3 (DMS), and dimethyl sulfoxide, CD3SOCD3, DMSO, have been studied at several wavelengths in the UV region (204-227 nm) using REMPI and time-of-flight mass spectrometry (TOFMS) to measure TOF profiles, rotational and vibrational REMPI spectra and rotational alignment of the CD3 fragment. The photodissociation of the DMS molecule has been studied in the first (215-230 nm) and the second (200-205 nm) absorption bands. In both cases, the analysis of the TOF profiles indicates a strongly anisotropic photodissociation (β=-0.9) with a large fraction (70-80% and 90%, respectively) of the available energy appearing as fragment recoil translation. In the first absorption band, this fraction is strongly dependent on the excitation wavelength, supporting the theoretical conjecture [1] that the photofragmentation occurs via an indirect, albeit rapid, process, involving two strongly coupled excited electronic states and a non-adiabatic decay [2]. The dissociation in the second absorption band seems to take place in a single purely repulsive potential energy surface. The analysis of the results for the photodissociation of DMSO shows that there exist, at least, three channels leading to formation of CD3. The primary dissociation, S-C bond cleavage, involves two competing channels with distinct translational energy distributions for the CD3 fragment. The major dissociation pathway, yielding relatively slow and isotropic CD3 fragments, proceeds in a statistical manner on the ground electronic surface following internal conversion. The second channel (parallel transition) produces a small percentage of anisotropic and faster CD3 through direct dissociation. By analysing the TOF profiles at different polarization angles of the dissociation laser and the rotationally-state resolved CD3 REMPI spectra, it has been possible to identify the percentage of the anisotropic dissociation.

[1] M.R. Manaa and D. R. Yarkony, J. Am. Chem. Soc. 116,11444 (1994) [2] J. Barr, I. Torres, L. Bañares, J. E. Verdasco, and F. J. Aoiz, Chem. Phys Lett. 373, 550 (2003).

37

R5

Photodissociation of Simple Aromatic Molecules Studied by Multimass Ion Imaging Techniques

Chi-Kung Ni Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan

An overview of our recent experimental studies of aromatic molecules using multimass ion imaging technique will be presented. Photodissociation of several simple aromatic molecules, including benzene, fluorobenzene, toluene, m-xylene, ethylbenzene, propylbenzene, phenol, pyridine, 4-methylpyridine, and aniline at 248 nm or 193 nm were investigated under collisionless condition. Photofragment translational energy distributions and dissociation rates were recorded. They revealed new isomerization and dissociation channels of these molecules. The experimental data will be discussed in reference to the ab initio potential energy surfaces and statistical theory results.

38

F1

Spectroscopy and Dynamics of NH Radical Complexes

Galina Kerenskaya, Udo Schnupf, and Michael C. Heaven Department of Chemistry, Emory University, Atlanta, GA 30322, USA

Spectroscopic and theoretical studies of the binary complexes of NH with He, Ne, and H2 are described. Interest in the NH-He complex stems from identification of NH(X) as a promising candidate for studies of ultra-cold molecules (paramagnetic ground state with a large rotational constant). With He buffer gas cooling the stability of NH in a magnetic trap depends on the details of the NH+He interaction potential. We have probed this interaction through studies of the A-X transition of NH-He. Preliminary observations appear to be in good agreement with the results of recent high-level theoretical calculations1. Studies of the A-X system of NH-Ne yield insights concerning the characteristic energy level patterns of 3Σ and 3Π complexes. Theoretical predictions have been used to guide the analysis of the congested ro-vibronic structure of NH(A)-Ne. The predictions were in qualitative agreement with the observed structure, but systematic quantitative errors were noted. Interestingly, contrasting errors were found for the singlet (a and c) and triplet (X and A) potential energy surfaces.

Complexes of NH with H2 are of interest as they may be used to examine NH+H2→NH2+H reaction dynamics. This reaction is endothermic for NH(X), so the existence of a stable

NH(X)-H2 complex is expected. Quenching data indicate that the reactions of NH(c) and

NH(A) with H2 do not encounter barriers. Preliminary work on NH-H2 shows that the ground state complex may be generated in a jet expansion and detected via excitation of the monomer A-X transition. The spectral features observed to date involve direct excitation of

" -1 the continuum. They define a ground state bond dissociation energy of D0 =35 cm . Experiments are in progress to determine the primary decay channels for the non-fluorescent quasi-bound levels of NH(A)-H2.

1. H. Cybulski, R. V. Krems, H. R. Sadeghpour, A. Delgarno, J. Klos, G. C. Groenenboom, A. van der Avoird, D. Zgid and G. Chalasinski, work in progress.

39

F2

Molecules in Cold Atomic Gases: How do They Interact?

Jeremy M. Hutson and Pavel Soldán

Department of Chemistry, University of Durham, Durham DH1 3LE, United Kingdom

There is great interest in cooling molecules and trapping them at temperatures below 1 milliKelvin and especially in producing quantum-degenerate gases of dipolar species. Over the last few years, several experimental methods have been developed to cool stable molecules and free radicals to temperatures of tens or hundreds of milliKelvin. These include buffer gas cooling in cryogenic helium [1], molecular beam decleration using switched electric fields [2], guiding of the cold fraction from a thermal gas [3], and crossed molecular beam scattering [4]. However, the cold molecules produced by such methods need further cooling to reach the ultracold regime below 1 milliKelvin. One promising candidate for this “second stage” cooling is to inject the cold molecules into a cold atomic gas of Rb or some other alkali metal and to rely on “sympathetic cooling” of the molecules. However, very little is known about the interactions between molecules and alkali metal atoms.

We have investigated the interaction between Rb and polar molecules such as NH and OH. We have carried out ab initio electronic structure calculations to characterize the surfaces. The strength of the interaction is found to depend very strongly on the spin states involved. For example, if Rb and NH collide with their electron spins parallel, they interact on a quartet surface (4A''). The interaction is then dominated by dispersion forces and is relatively weak, with a well depth of 0.078 eV. If the two species are not spin-aligned, however, they can interact on the lowest doublet surface (2A''), which has a very much stronger interaction potential (well depth 1.372 eV) because it is an ion-pair state with an attractive Coulomb interaction at short range. The dispersion-bound doublet state crosses the ion-pair state at conical intersections at linear geometries. In this case, strong collisions can occur via a harpoon mechanism. This effect may be undesirable for sympathetic cooling, because it may enhance reorientation and three-body collision rates, but it might also be used for production of extremely polar ultracold molecular complexes. For RbNH, there are electronically excited states correlating with Rb (2P) that have reasonable Franck-Condon factors to both the low-energy continuum state Rb (2S) + NH(3Σ) and the ion-pair bound state Rb+NH–. It may thus be possible to form the very polar Rb+NH– species by stimulated Raman pumping or even by spontaneous emission.

Similar deeply bound ion-pair states exist for other alkali atom – molecule pairs such as Rb–OH, but not for Rb–HF.

References

[1] J. D. Weinstein, R. deCarvalho, T. Guillet, B. Friedrich and J.M. Doyle, Nature 395, 148 (1998). [2] H. L. Bethlem and G. Meijer, Int. Rev. Phys. Chem. 22, 73 (2003). [3] S. A. Rangwala, T. Junglen, T. Rieger, P. W. H. Pinkse and G. Rempe, Phys. Rev. A 67, 043406 (2003). [4] M. S. Elioff, J. J. Valentini and D. W. Chandler, Science 302, 1940 (2003). [5] P. Soldán and J. M. Hutson, Phys. Rev. Lett. 163202 (2004).

40

F3

Optical Stark and Zeeman Spectroscopy of Transition Metal Containing Radicals

Timothy C. Steimle Department of Chemistry and Biochemistry Arizona State University Tempe, AZ 85287-1604, U. S. A.

Identification and characterization transition metal (TM) metal containing radical molecules formed in the reaction of TM atoms or clusters with simple gaseous reagents provide insight into corrosion and catalysis. As is evident from the multitude, and variety, of molecules identified using time-of-flight mass spectrometry, the difficulties of synthesizing these ephemeral molecules in the gas phase has largely been overcome by implementing the laser ablation/gaseous reagent supersonic expansion schemes. Generating collimated molecular beams and recording the resonant optical spectra at near natural linewidth limits for the multitude of diatomic molecules produced in these sources is now relatively straightforward. The ground and excited electronic state permanent electric dipole moments, extracted from analyzing these optical spectra recorded in the presence of a static electric field, have been used to establish trends in chemical bonding. The results of our Stark measurements for diatomic TM nitrides, oxides and carbides will be presented and compared with simple molecular orbital correlation models and sophisticated ab initio predictions. The number of TM-containing polyatomic molecules for which ultrahigh resolution electronic spectra have been recorded and analyzed is relatively small due in part to the traditional reliance upon LIF detection. Most notable exceptions are the studies of the dihalides by the Oxford group [1] and the cyanides [2] and methylidynes [3] from by the UBC group. Recently detected of PtNH and ScCN will be given as examples from our laboratory. Efforts to apply the absorption-based technique of transient frequency modulation spectroscopy [4, 5] to the study of these TM containing polyatomic as well as other diatomic molecules will be summarized. Although less frequently implemented, optical Zeeman spectroscopy can also provide valuable insight in the nature of the electronic states through the determination of magnetic g-factors. Results of our recent optical Zeeman spectroscopic measurements on the A 3Φ - 3 2 2 + 2 + X ∆ band system (“γ-band”) of TiO and the A Π/B Σ - X Σ band systems of , CaH, will be presented. These molecules are proposed as probes of the ambient magnetic field in the sun [6]. The goal here is twofold: a) determine magnetic tuning rates for visible and near infrared spectral features, b) use the extracted g-factors to analyze the electronic state composition.

1. S. Ashworth and J.M. Brown, J. Mol. Spectrosc. 191, 276-285 (1998). 2. C.T. Kingston, A.J. Merer, T.D. Varberg, J. Mol. Spectrosc. 215(1), 106-127 (2002). 3. M. Barnes, A.J. Merer, and G.F. Metha, J. Mol. Spectrosc. 181, 168-179 (1997) 4. J.C. Bloch, R.W. Field, G.E. Hall, and T.J. Sears, J. Chem. Phys. 101, 1717-1720 (1994). 5. T.C. Steimle, M. L. Costen, G.E. Hall, and T. J. Sears, Chem. Phys. Lett, 319, 363-367 (2000). 6. S. V.Berdyugina, and S. K.Solanki, Astronomy and Astrophysics 385(2), 701-715 (2002)

41

F4

The Bending Vibrational Levels + of C3-Rare-Gas Atom Complexes and C2H2 Yen-Chu Hsu1,2 1Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan, R. O. C. 2Department of Chemistry, National Taiwan University, Taipei 106, Taiwan, R. O. C.

Bending vibrations of polyatomic molecules have a strong influence on molecular dynamics since they can lift the degeneracies of electronic states and/or cause state mixings. They are not always easy to observe since they often have low frequencies. The bending levels of two molecular systems have been studied in this work: C3-rare gas van der Waals + complexes and the acetylene cation, C2H2 .

The bending vibrational levels (υb=1-10) of the ground states of the C3-rare gas complexes were probed by wavelength-resolved emission from several vibronic levels of the à state.[1] The level structure of the two bending vibrations of each complex, except that of

C3-Ne, has been fitted to a perturbed harmonic oscillator model, where the potential function 2 has the form V = V1r cosθ +V2r cos 2θ (r is the amplitude of the C3-bending motion and θ gives the orientation of the rare gas atom relative to the plane of the bent C3 molecule). The potential function of each complex, obtained from the model fit, will be compared with that from our ab initio calculations. ~ 2 + The trans- and cis-bending vibronic levels of the X Πu state of C2H2 have been recorded by 1+1′ two-color ZEKE photoelectron spectroscopy via single ro-vibrational levels 1 + of the à Au state of C2H2. Thirty-eight vibronic levels of C2H2 with υ4=0-6, υ5=0-2 and K=0-3 have been fitted using a model for the interaction of the electron orbital angular momentum with the two degenerate bending vibrations and the electron spin. [2] (υ4 and υ5 are the trans- and cis-bending vibrations, respectively). The level structure is complicated by strong Darling-Dennison resonance between the two bending manifolds; a similar effect has been previously reported in the ground electronic state of acetylene itself. [3]

[1] G. Zhang, B.-G. Lin, S.-M. Wen, and Y.-C. Hsu, J. Chem. Phys. 120, 3189(2004). [2] (a) J. T. Hougen, J. Chem. Phys. 36, 519(1962); (b) J. M. Brown, J. Mol. Spectrosc. 68, 412(1977). [3] J. Plíva, J. Mol. Spectrosc. 44, 145(1972).

42

F5

Electronic Spectra of Carbon Chains and their Relevance to Astrophysics

John P. Maier Department of Chemistry, University of Basel Klingelbergstrasse 80, CH-4056 Basel, Switzerland

The electronic spectra of neutral carbon chains, their cations and anions have been obtained in the gas phase. Four different approaches have been used. The transitions of the chain radicals C2nH n=3-6 and of the bare carbons C4, C5, have been detected by cavity ringdown spectroscopy with a supersonic slit-discharge source. The electronic spectra of the

+ + polyacetylene and cyanopolyacetylene cations such as HC2nH and HC2nCN n=2,3 have been measured at high resolution in cell and jet discharges at low temperatures using frequency

- - modulation absorption spectroscopy. Carbon anion chains of the type Cn and CnH with n in the range 3-10 have been studied by a two colour resonant photodetachment approach. The electronic transitions of very long polyacetylene chains HC2nH n-4-13 have also been detected in the gas phase by a two photon ionisations technique. The gas phase spectra obtained in the laboratory have enabled for the first time a direct comparison with astronomical measurements in the diffuse medium for polyatomic carbon chains to be made. The implications of this are discussed.

43

44

Abstracts of Posters

45

46

A1-01

Three-Body Dissociation Dynamics of the Low-Lying Rydberg States of H3

Christopher M. Laperle, Jennifer E. Mann and Robert E. Continetti Department of Chemistry and Biochemistry, University of California, San Diego 9500 Gilman Drive, La Jolla, CA 92093-0340

+ The dominant source of H3 depletion in interstellar clouds is dissociative recombination (DR) with free electrons and electron-donor molecules. Capture of free electrons at or near the H3 ionization threshold leads to both two and three-body DR processes, involving a number of the Rydberg states of H3 with geometries near the D3h ground state of + 2 H3 . The lone dissociative state in this region, the ground 2p E′ state, provides the primary route to dissociation, however, non-adiabatic transitions from high-lying Rydberg states to the lower-lying Rydberg states are thought to play an important role in DR as they are most efficiently predissociated by the 2p 2E′ state. This degenerate dissociative state undergoes a Jahn-Teller distortion into upper and lower repulsive sheets as the nuclei are distorted from C3v symmetry. These sheets correspond to the three- and two-body dissociation limits respectively. The coupling between the Rydberg states and the upper sheet of the 2p 2E′ dissociative state governs three-body dissociation. To examine the three-body dissociation dynamics of the three-lowest Rydberg states + of H3, we have prepared these states by charge-exchange of H3 with cesium. Translational + + spectroscopy of three-body dissociative charge exchange products of fast (3-12 keV) H3 , D3 , + + D2H and HD2 with Cs have been performed. Production of the cations in a supersonic + expansion yields a rotationally and vibrationally cold source of H3 and the isotopomers. A well-resolved kinetic energy release spectrum was obtained, allowing the three-body dissociation dynamics of the three lowest Rydberg states to be obtained. The momentum partitioning among the three H atoms provides a measure of the 2 2 2 nuclear configuration at the point of dissociation for the 2s A1′, 2p A2″ and 3p E′ states for 2 H3. The data for H3 reveals that the 2s A1′ state undergoes three-body dissociation by a C2v 2 distortion towards a linear configuration. The 2p A2″ rotationally couples to the dissociative ground state largely preserving the initial symmetric configuration, and thus leading to nearly equal momenta among the products. The most complex dynamics are observed from the 3p 2E′ state where totally symmetric and asymmetric features are observed with almost equal probability. This may be interpreted as capturing the Jahn-Teller distortion the nascent 3p 2 E′ state undergoes. D3 exhibits subtle dynamical differences compared to H3 as a result of the 2 difference in the zero-point energy. For example, the 2p A2″ state shows a higher probability for dissociation away from the totally symmetric geometry. This data provides valuable information for the development and evaluation of future theoretical models involving the H3 potential energy surface. Extension of these efforts to studies of the dissociative recombination of free electrons with larger polyatomic cations is now undersay. A trochoidal monochromator has been constructed, allowing merged beam studies of dissociative recombination dynamics and product branching ratios. Progress on these studies will be reviewed. This work is supported by AFOSR grant FA9550-04-1-0035.

47

A1-02

Reaction Dynamics of Isotope Exchange Reaction of Singlet Oxygen Atom with Carbon Dioxide Molecule: A Crossed Molecular Beam Study

1,5 2 2 2,3 Jim J. Lin , Mark J. Perri , Annalise L. van Wyngarden , Kristie A. Boering , Yuan T. Lee1,4 1 Institute of Atomic and Molecular Science, Academia Sinica, Taipei, Taiwan 2Department of Chemistry, University of California, Berkeley, California, USA 3Department of Earth and Planetary Science, University of California, Berkeley, California, USA 4Department of Chemistry, National Taiwan University, Taipei, Taiwan 5Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan

18 1 44 The dynamics of the O( D) + CO2 oxygen isotope exchange reaction has been studied using a crossed molecular beam apparatus at collision energies of 4.2 and 7.7 kcal/mol.

Besides isotope exchange together with quenching to ground state O(3P), a new isotope exchange channel in which the product oxygen atom remains on the singlet surface is observed at both collision energies . Electronic quenching of O(1D) is the major channel at both collision energies, accounting for 84% of isotope exchange at 4.2 kcal/mol and 67% at

7.7 kcal/mol. Isotropic product angular distributions suggest that both channels proceed via a

* CO3 complex that is long-lived with respect to its rotational period. Combined with recent ab initio and statistical calculations by Mebel et al., the long complex lifetimes suggest that

* statistical isotope exchange occurs in the CO3 complex, although the existence of a small, dynamically-driven unconventional isotope effect in this reaction cannot yet be ruled out.

These new molecular-level details may help provide a more quantitative understanding of the heavy isotope enrichment in CO2 observed in the stratosphere.

48

A1-03

Photoisomerization and Photodissociation of Aniline and 4-Methylpyridine

Chien-Ming Tseng,1 Yuri A. Dyakov,1 Cheng-Liang Huang,1,2 Alexander M. Mebel,1,3, Sheng Hsien Lin, 1,4 Yuan T. Lee,1,4 and Chi-Kung Ni1* 1Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan. 2Present address: Department of Applied Chemistry, National Chiayi University, Chiayi, Taiwan. 3Present Address: Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 USA. 4Chemistry Department, National Taiwan University, Taipei, Taiwan

Photofragment translational energy distributions and dissociation rates of aniline and

4-methylpyridine at 193 nm were studied by multimass ion imaging techniques. Five dissociation channels were observed in aniline, including the four major channels of H, H2,

NH2, and NH3 eliminations and one minor channel of CH3 elimination. On the other hand, H atom and CH3 eliminations were found to be the major channels of 4-methylpyridine and NH2 and NH3 were found to be the minor channels. d5-aniline and d3- 4-methylpyridine were also studied. H and D atom exchange before dissociation were observed for both molecules. Our results demonstrate that more than 23% of the ground electronic state aniline and 10% of p-methyl-pyridine produced from the excitation by 193 nm photons after internal conversion isomerize to 7-membered ring isomers, followed by the H atom migration in the 7-membered ring, and then rearomatize to both methyl-pyridine and aniline prior to dissociation. The significance of this isomerization is that the carbon, nitrogen, and hydrogen atoms belonging to the alkyl or amino groups are involved in the exchange with those atoms in the aromatic ring during the isomerization.

49

A1-04

H-atom Elimination of n-Propyl and iso-Propyl Radicals: A Photodissociation Study

Weidong Zhou, Yan Yuan, and Jingsong Zhang

Department of Chemistry and Air Pollution Research Center University of California, Riverside, CA 92521-0403 U. S. A.

The H-atom elimination channels in the UV photodissociation of jet-cooled n-propyl and iso-propyl radicals are studied in the region of 237 nm using the high-n Rydberg-atom time-of-flight technique. Upon excitation to the 3p state by the UV photolysis radiation, n-propyl radical and iso-propyl radical dissociate into the H atom and propene products. The product center-of-mass translational energy release of both n-propyl and iso-propyl radicals have bimodal distributions. The H-atom product angular distribution in n-propyl is anisotropic (with β ~ 0.5), and that in iso-propyl is isotropic. The overall average translational energy release is 〈ET〉 ~ 0.27Eavail for n-propyl and 〈ET〉 ~ 0.21Eavail for iso-propyl.

The bimodal translational energy distributions suggest two dissociation pathways: (i) a unimolecular dissociation pathway from the ground-state propyl after internal conversion from the 3p state, and (ii) a repulsive pathway directly connected with the excited state of the propyl radical. Isotope labeling studies have also been carried out. The possible photodissociation mechanisms will be discussed.

50

A1-05

Studies of Photodissociation Dynamics Using Selective Photoionization

Shih-Huang Lee Research Division, National Synchrotron Radiation Research Center (NSRRC) 101 Hsin-Ann Road, Science Park, Hsinchu 30077, Taiwan, R.O.C. Yuan T. Lee Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica P.O. Box 23-166, Taipei 106, Taiwan, R.O.C.

Products from photodissociation of small molecules have been detected successfully using the technique of photofragment translational spectroscopy associated with synchrotron-based photoionization at NSRRC. Compared to conventional electron impact ionization, direct photoionization with an intense tunable VUV beam has more advantage in chemical dynamics research. Molecular and radical products even though atomic and molecular hydrogen can be detected in our molecular beam apparatus. Photodissociations of several small olefins, alkyl halides, and cyclic compounds have been carried out at 193- or 157-nm excitation.

With such high excitation energy molecules decompose through various dissociation pathways. Product kinetic energy distributions, branching ratios, and angular anisotropy parameters (β) have been unraveled from complicated multichannel dissociations. The measurements of product kinetic energy distributions and branching ratios allow us to reveal dissociation dynamics and to understand whether photoexcited molecules dissociate directly from a repulsive state or from electronic ground state following nonadiabatic transition. The measurements of product angular distributions allow us to estimate the axis of transition dipole moment and symmetry of photoexcited state, and to facilitate the recognition of dissociation process.

51

A1-06

Imaging the Mode-Correlation of Product Pairs 0 0 : OH + CD4 → CD3 (00 Q, 22 Q) + HOD (ν1 ν2 0)

Bailin Zhang, Weicheng Shiu, Jim J. Lin, and Kopin Liu

Institute of Atomic and Molecular Sciences, Academia Sinica P.O. Box 23-166, Taipei, Taiwan 106

A crossed molecular beam investigation of the title reaction has been performed, using the time-sliced ion velocity imaging technique [1] to map out the mode- and state-correlation of the two coincident product pairs. A (2+1) REMPI scheme was used to interrogate the

0 products. When the ground state CD3 (00 Q) product is probed, the co-products HOD are mainly backward scattered. And the correlated vibrational branching ratios of the HOD ( ν1 ν2

0 ) are in the order of (200) >> (100) > (110). Here, we adapt the notation of (νOD νbend νOH) to designate the vibration excitation of the HOD products. The strong similarity between these findings and those from the analogous OH + D2 → HOD + D reaction [2] seems to suggest the spectator role of the CD3- moiety in the present reaction. On the other hand, as the

0 umbrella-excited CD3 (22 Q) product is probed, the angular distribution shifts to sideways peaking. And the correlated vibrational population of HOD changes to (100) > (110) > (200) - ≈ (010) ≈ (000), indicating that the CD3 moiety is in fact a very active participant in this reaction, although the OH bond remains an innocent bystander. The latter conclusion receives strong support from further investigations of the primary and secondary isotope effects, in which the nascent vibrational distribution of HOD was found to be very bond-specific with most of vibrational excitation resided in the newly formed OH or OD bond and the old OH/OD bond remained largely unexcited.

[1] J. J. Lin, J.G. Zhou; W.C. Shiu; K. Liu, Rev. Sci. Instrum. 74, 2495 (2003) [2] B. R. Strazisar; C. Lin; H. F. Davis, Science 290, 958 (2000)

52

A1-07

Photodissociation of 4-Picoline, Aniline and Pyridine: Ab Initio and RRKM Study

Yuri A. Dyakov,1 Alexander M. Mebel,1,2 S. H. Lin, 1,3 Yuan T. Lee,1,3 and Chi-Kung Ni1

1 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan. 2 Present Address: Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 USA. 3 Chemistry Department, National Taiwan University, Taipei, Taiwan

Photodissociation of 4-picoline, aniline and pyridine molecules at 6.4 eV in singlet state was studied by ab initio quantum chemical calculations. Geometry optimization was performed by DFT B3LYP/6-31G* approach. Energy of intermediates and transition states was specified by Gaussian-3 computational scheme. The major decomposition path for

4-picoline is H-atom elimination from CH3-group (91.0 kcal/mol), CH3 elimination (105.9 kcal/mol), HCN elimination (112.4 kcal/mol through complex of 3 and 5-member ring and

115.8 kcal/mol through 7-member ring), and H2 elimination (114.6 kcal/mol). The major decomposition path for aniline is NH3 elimination (72.0 kcal/mol), H-atom elimination from

NH2 group (88.7 kcal/mol), NH2 elimination (96.1 kcal/mol). In addition to dissociation, isomerization reactions for picoline and aniline are also possible. The main isomerization products are 3-picoline, 2-picoline and aniline for 4-picoline, and 4-picoline, 3-picoline, 2-picoline for aniline. The major decomposition path for pyridine is HCN elimination. There are many possible ways for this reaction. The preferable reactions are HCN + CH2CHCCH (linear fragment, 97.3 kcal/mol and 100.7 kcal/mol), HCN + C4H4 (4-member ring, 111.3 kcal/mol),

HCN + CH2C3H2 (3-member ring, 113.1 kcal/mol). The next decomposition path for pyridine is CHCCH2 + NCCH2 109.8 decay (kcal/mol). There are 4 possible ways for this reaction with the same final products. The next reaction, CH3 elimination, has 3 possible ways with 2 possible products: CH3 + NCCCCH2 (114.3 kcal/mol) and CH3 + NCCHCCH (113.8 kcal/mol). H-atom elimination is possible from base pyridine through 3 channels: from ortho- (106.1 kcal/mol), meta- (112.3 kcal/mol), and para- (110.6 kcal/mol) positions. The reaction of H2-elimination (many possible ways, the lowest barrier is 108.9 kcal/mol), C2H2 elimination (the lowest barrier is 101.8 kcal/mol) and C2H4 elimination (the lowest barrier is 111.3 kcal/mol) also possible but labored through high intermediate barriers.

53

A1-08

Isomeric Species CH2SH and CH3S Formation from Photodissociation of Methanethiol at 157 nm

Yin-Yu Lee*, Tzan-Yi Dung, and Shih-Huang Lee National Synchrotron Radiation Research Center, 101 HsinAnn Road, Hsinchu Science Park, Hsinchu 300, Taiwan

Wan-Chun Pan and I-Chia Chen National Tsing Hua University, 101, Section 2 Kuang Fu Road, Hsinchu 300, Taiwan

Jr-Min Lin, Xueming Yang, and Yuan T. Lee Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-116, Taipei 107, Taiwan

Synchrotron radiation has been used to investigate the photodissociation of methanthiol

(CH3SH) by the technique of photofragment translational spectroscopy using a molecular beam apparatus. Although it is well established experimentally that, at 275-193 nm region, 1 states of CH3SH, 1, 2 A” are excited and both states decompose to CH3S + H channel which is dominant the product branching. We investigate the photodissociation of CH3SH at 157 nm, the S-H fission is a prominent reaction channel still, in addition, a new atomic hydrogen channel is found from the analysis of translational spectroscopy. By tuning the undulator of synchrotron, we found the fragment translational spectra shown different shapes at gap 27 and

28mm, equivalent to 8.6 and 9.5 eV, respectively, absent of CH3S component from the m/e=47 translational spectra at lower photoionization energy, so that we can extract CH2SH signal from m/e=47 bundle. In addition, from the cracking of photoionization of m/e=47, TOF spectra of CH3 and CH2 products showed that the cracking comb come from CH3S and

CH2SH components, respectively. On the other hand, experimental results of m/e=2 from carbon deuterated isotope, CD3SH, shown with momentum-matching to m/e=49, CD2SH fragment, confirms isomeric transient species CH2SH and CH3S both are primary products from the photodissociation of 157 nm.

54

A1-09

Photodissociation of Fluorobenzene (C6H5F) at 193 nm Monitored with Time-resolved Fourier-transform Infrared Emission Spectroscopy

Chia-Yan Wu1, Yu-Jong Wu1, and Yuan-Pern Lee1, 2 1 Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan 2 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan

Rotationally resolved emission of HF up to v = 4 is observed after photolysis of C6H5F at 193 nm. In the period 0.5-1.5 µs after photolysis, HF (v≤4) show similar Boltzmann-type rotational distribution; with a short extrapolation a nascent rotational temperature 1960 ± 150

K and an average rotational energy of 15 ± 3 kJ mol-1 are determined. Observed vibrational distribution of (v = 1) : (v = 2) : (v = 3) : (v = 4) = (60±7) : (24±3) : (10.5±1.2) : (5.3±0.5) corresponds to a vibrational temperature of 6400 ± 1800 K with an average vibrational energy

9 −1 of 33 ± 2 kJ mol . A moderate fraction of available energy is partitioned into the internal

0.03 energy of HF, with fv ≅±0.10 0.01 and fr ≅ 0.045 ± 0.006 . Our observed internal energy distribution of HF and corresponding distribution of translational energy reported by Huang et al [1] indicated that the reaction process via four-center (α, β) elimination channel. A modified impulse model considering displacement vectors of transition states during bond breaking predicts the rotational distributions of HF satisfactorily for four-center elimination channels of CF2CHCl and C6H5F. Partition of vibrational energies into HF in these systems is also consistent with the distances of H－F predicted for associated transition state.

[1] C.-L. Huang, J.-C. Jiang, A. M. Mebel, Y. T. Lee, C.-K. Ni, J. Am. Chem. Soc. 125, 9814 (2003). [2] C.-Y. Wu, C.-Y. Chung, Y.-C. Lee, and Y.-P. Lee, J. Chem. Phys. 117, 9785 (2002)

55

A1-10

Ultrafast Photodissociation Dynamics of Acetone S2 State at 195 nm

Wei-Kan Chen, Jr-Wei Ho, and Po-Yuan Cheng Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan

We have investigated the photodissociation dynamics of acetone S2 (n,3s) state by using the combination of femtosecond laser spectroscopy and kinetic-energy resolved time-of-flight (KETOF) mass spectrometry. In our study acetone was excited at 195nm and the ion intensities at the parent (58 amu), acetyl (43 amu) and methyl (15 amu) mass channels were monitored to obtain the corresponding fs mass-resolved transients. The free CH3 fragments were detected via a 2+1 REMPI scheme at 333.4nm and their translational energy distributions were measured at different times after the initial excitation by the fs-KETOF technique. This is the first time the temporal evolution of all species involved in the reaction, i.e. the initial state, intermediates and products, are probed simultaneously in real time for the photodissociation of acetone. Our results [1] support the newly proposed mechanism by Diau et al [2], in which the primary dissociation occurs via a relative lower barrier on the S1 surface to yield an acetyl radical in its first excited state with a linear geometry. The CH3CO(Ã) then rapidly internally converts to its ground state and subsequently decomposes into a carbon monoxide and another methyl radical.

[1] W. K. Chen, J. R. Ho, and P. Y. Cheng, Chem. Phys. Lett. 380, 411 (2003) [2] E. W. G. Diau, C. Kotting, T. I. Solling, and A. H. Zewail, Chem. Phys. Chem. 3, 57(2002)

56

A1-11

Quasiclassical Trajectory Studies of the F + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

J. F. Castillo1, F. J. Aoiz1, L. Bañares1, S. Vazquez2, E. Martinez-Nuñéz2, A. Fernandez-Ramos2

1Departamento de Química Física I, Universidad Complutense de Madrid, Madrid 28040, Spain 2Departamento de Química Física, Universidad de Santiago de Compostela, Santiago de Compostela, Spain

The field of chemical reaction dynamics is progressing in the study polyatomic reactive systems with increasing accuracy both from the experimental and theoretical sides. The most recent experiments are capable of extracting quantum state resolved information of poliatomic reactive events. Thus, it is desirable to be able to perform full dimensionality calculations using accurate potential energy surfaces (PES). However, the construction of an accurate global multidimensional PES is a difficult task. Recently, an interpolation method for the representation of the PES, that uses ab initio quantum chemistry calculations of the molecular electronic energy, gradients and hessians, has been developed [1]. The method appears to be a promising route to carry out chemical reaction dynamics studies of polyatomic reactions. We have explored the efficiency of the interpolation method by performing Quasiclasical Trajectory (QCT) calculations for the reaction

F + CH4 → HF + CH3 employing PES constructed by interpolation of ab initio Quantum Chemistry data. The ab initio calculations have been carried out using the MP2/aug-cc-pVDZ method. Integral cross sections, rovibrational distributions of the HF co-product and differential cross sections at collision energies between 1 to 4 kcal mol-1 [2-4] will be presented at the conference.

References:

1. M. A. Collins. Theor. Chem. Acc. (2002) 2. W. Shiu, J. J. Lin, K. Liu, Phys. Rev. Lett. 92,103201-1,(2004) 3. W. Shiu, J. J. Lin, K. Liu, M. Wu, D. H. Parker, J. Chem. Phys 120,117,(2004) 4. W. W. Harper, S. A. Nizkorodov, D. J. Nesbitt, J. Chem. Phys. 113,3670, (2000)

57

A1-12

Kinetics of the Reactions of Methyl Radical with HCl and DCl at Temperatures 188 – 500 K: Tunneling

Arkke Eskola, Jorma Seetula, and Raimo Timonen Laboratory of Physical Chemistry, University of Helsinki, PO Box 55 (A.I. Virtasen aukio 1), FIN-00014 Helsinki, Finland, [email protected]

The kinetics of the reactions of CH3· with HCl and DCl at temperatures between 188 and 500 K have been studied in a flow reactor coupled to a photoionization mass spectrometer

(PIMS) using pulsed laser photolysis at 193 nm of the acetone along the laminar flow reactor to produce radicals homogenously in the reaction mixture. The decay profiles of the radical signals in absence and presence of and deuterium chloride in various concentrations were monitored in the time-resolved experiments by using the LP-PIMS apparatus1.

The rate coefficients of the reactions were independent of the bath gas pressure within the experimental range (2 – 6 Torr of He) at measured temperatures. The rate coefficients of the reactions of CH3 with HCl and DCl will be given at the meeting as well as the explanation of the other results including the effect of tunneling of H-atom on the rate coefficient at lower temperatures, comparison to the previous experimental data2 at 297 K as well as the details of the experimental methods used in the work.

References 1. A. Eskola and R. Timonen, Physical Chemistry Chemical Physics 5 (2003) 2557. 2. J. Russell, J. Seetula, S. Senkan, and D. Gutman, Int. J. Chem. Kin. 20, (1988) 759.

58

A1-13

Kinetics of the NCN + NO Reaction

S. Y. Tseng1, C. L. Huang1, T. Y. Wang1, and N. S. Wang*,1, Z. F. Xu2, and M. C. Lin*,1,2

1Department of Applied Chemistry and Center for Interdisciplinary Molecular Science, Chiao Tung University, Hsinchu, Taiwan 30010 2Department of Chemistry, Emory University, Atlanta, GA 30322, USA

A laser photolysis - laser induced fluorescence system has been used to study the reaction kinetics of NCN radical with NO. NCN were produced by photolyzing NCN3 molecules at 193 nm and monitored at 329 nm. We observed pressure effect and negative temperature-dependence for the rate coefficients of the title reaction in 40 –600 torr of He and

N2 and over the temperature range of 254 – 353 K.

Our results will be compared with a previous measurement and the result of a theoretical calculation based on ab initio MO (at the G2M level) and multichannel canonical variational

RRKM calculations.

59

A1-14

Single-electron hydrogen bonds in the methyl radical complexes H3C···HF

and H3C···HCCH: an ab initio study

Bing-Qiang Wang, Zhi-Ru Li*, Di Wu, Xi-Yun Hao, Ru-Jiao Li, and Chia-Chung Sun State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, 130023 P.R. China

The methyl radical (CH3) complexes with (HF) and ethyne (HCCH) are reported to show the existence of a single-electron hydrogen bond. Their geometrical structures are optimized at the MP2/aug-cc-pVDZ and MP2/aug-cc-pVTZ levels and C3v stationary structures are obtained for the two complexes. The single-electron hydrogen bond energies of H3C···HF and H3C···HCCH are calculated at six levels of theory [SCF, MP2, MP3,

MP4, CCSD, and CCSD (T)] and their harmonic vibrational frequencies are calculated at the

MP2/aug-cc-pVTZ level.

H H r1 汐 r1 汐 C H F C H C C H R R H r2 H r2 r3 r4 H H

Fig. 1. Optimized structures of H3C···HF and H3C···HCCH with a single-electron hydrogen bond.

60

A1-15

Dynamics of Photoluminescence in Bistriphenylene

P. G. Hela, H.–T. Shih, C.–H. Cheng and I–C. Chen Department of Chemistry, National Tsing Hua University, Hsinchu-300, Taiwan

2,2’-Bistriphenylene (BTP)1, a blue emitter in light emitting device (LED) has excellent electroluminescent (EL) and photoluminescent efficiencies2. It exists as a monomer in solution and undergoes aggregation on thin film formation, observed from the red-shifted emission spectra and long fluorescence lifetimes. In the film, the splitting of the absorption band of monomer into two components, a blue shifted absorption spectrum with a red-shifted shoulder, was observed. There is an energy gap of 0.9 eV between the lowest energy absorption and highest energy emission bands. The above two features suggest H-aggregation in film with Davydov splitting rather than co-existence of aggregates. Further, the two emission bands display a well defined separation of 0.1 eV, associated with two states with origin at 2.68 eV and 2.51 eV and many underlying states. These bands are the most intense with the low energy, weak, and unpolarized bands of the absorption spectrum, suggesting that the lowest energy excited state is allowed, in contrast to the conventional H-aggregation owing to the destructive interference of excited state transition dipole moments. The life time of this lowest energy excited state is 3.61 ns, as observed from time correlated single photon counting experiments. The intermediate states have shorter lifetimes, 168 and 660 ps. Determined by Fluorescence Upconversion method. The long axis, hence the transition dipole moment, is aligned along the surface of the film according to its polarized absorption and PL spectra. The sharp and main absorption bands in the oriented films are located at higher energies compared to the lowest excitation band of the monomer. These optical transitions of coupled electronic oscillators can be described with the molecular exciton model developed by Spano3. The spectral structures imply parallel-oriented transition dipoles resulting in the formation of an exciton band with the only allowed transition to the higher-energy state. Unlike in the conventional H-type, the transition dipole moments constructively interfere, and result in emissive H-aggregates. A detailed dynamics of the photophysics of BTP relating to its excellent EL efficiency in the film will be discussed. [1] H.-T. Shih, H.-H. Shih and C.-H. Cheng, Org. Lett. 3, 811 (2001). [2] H.-T. Shih, C.-H. Lin, H.-H. Shih and C. -H. Cheng, Adv. Mater. 14, 1409 (2002). [3] F. Spano, Chem. Phys. Lett. 331, 7 (2000).

61

A1-16

Ultrafast Interfacial Electron Transfer Dynamics 2+ of the TiO2 Nanostructures Functionalized by the Ru Complexes

Chih-Wei Chang and Eric Wei-Guang Diau* Department of Applied Chemistry and Center for Interdisciplinary Molecular Science,

National Chiao Tung UniVersity, Hsinchu, Taiwan 30050, Republic of China I-Jy Chang* Department of Chemistry, National Taiwan Normal UniVersity, 88 Tingchow Road Section 4, Taipei 11718 Taiwan, Republic of China

Interfacial electron transfer dynamics between the TiO2 nanostructures and the photosensitizers (Ruthenium complexes with structures shown below) have been investigated using the time-correlated single photon counting and the femtosecond fluorescence up-conversion techniques. The emissions of the solid-state films of the Ru-complex powders show prominent long-lifetime components resulting from the 3MLCT state of the complexes.

However, the emissions are significantly quenched in the functionalized Ru-TiO2 nanocrystalline film due to the ultrarapid interfacial electron transfer rate (<200fs-1) with respect to the relatively slower 1MLCT → 3MLCT intersystem-crossing (ISC) rate (~3ps-1). 2+ We found that the main difference between the N3-dye TiO2 film and the other Ru TiO2 films is the relative amplitude of the slow decay component, which is much smaller for the former. This dynamical evidence indicates that the competition between the interfacial electron transfer and the 1MLCT→3MLCT ISC processes should play an important role in determination of the performance of a photovoltaic device.

Cl

COOH

Cl N COOH N N N HOOC N N N N N N Ru N Ru N Ru N N N N N N N Ru Cl N N COOH N COOH COOH SCN NCS COOH Cl

N3-dye Ru(phen)2tmma Ru(bpy)2m-OH Ru(Cl2bpy)2tmma

62

A1-17

Time Resolved FTIR Emission Studies of Molecular Dynamics

G. Hancock, M. Morrison, M. Saunders Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK

We report here a number of time resolved FTIR emission measurements involving the 1 dynamics of free radical reactions. Firstly, 193 nm photolysis of N2O produces O( D) which subsequently reacts with N2O: 1 O( D) + N2O → NO + NO

→ N2 + O2 The first reaction channel produces NO that is vibrationally excited (ν = 1-16) and has been exploited to obtain the rates of collisional deactivation of NO(ν) by a number of atmospherically important species, including O2 and NO. Excellent agreement has been found with literature data, and approximately forty new rate constants are reported here. In particular the newly measured NO self quenching rates fill the gap between previous measurements at low ν (where the rate constants decrease with increasing ν) and high ν (where they show the opposite trend).

Secondly, the photodissociation of NO2/N2O4 at 193 nm has been investigated. NO and NO2 nascent products have been observed and the nascent vibrational distribution of the NO product measured using both the fundamental and overtone bands of NO. The distribution peaks at ν = 5, in agreement with lower energy studies, but also has a secondary maximum at ν = 14, possibly due to dissociation via a crossing to another potential energy surface.

Thirdly, the reaction of O(1D) with fluoromethanes has been studied. A number of reaction products have been observed, including H2CO and F2CO, and particular attention has been paid to the nascent vibrational energy distribution of the HF product. The fate of the O(1D) reactant has also been investigated to determine the relative disposal of energy via 1 reaction and energy transfer, particularly with respect to O( D) + CF3H.

63

A2-01

Fourier-Transform Microwave Spectroscopy of CCCl and CCCCCl

Kaoru Katoh, Yoshihiro Sumiyoshi, Taketoshi Ueno, and Yasuki Endo

Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan

Pure-rotational transitions of the CnCl (n=2, 4) radicals, chlorine derivatives of CnH (n=2, 4), have been observed by Fourier-transform microwave spectroscopy. These radicals were produced in a supersonic jet by a pulsed electric discharge of 0.3% of carbon tetrachloride

(CCl4) in Ne. Rotational transitions with spin and hyperfine splittings were observed, and the molecular constants have been precisely determined for CCCl. This radical shows a spectral pattern for a molecule with 2Σ symmetry as is the case for CCH. Ab initio calculations at the MRCI level with the cc-pVTZ basis set have revealed that the first excited electronic state corresponding to the 2Π state at linear geometry is very close to the ground electronic state, and the two states are more strongly interacting with each other than the case of CCH. Based on the results of the ab initio calculations and the determined molecular constants, it was found that a conical intersection due to a strong vibronic coupling exists, and the radical has a bent structure in the ground state (Figure). Rotational spectra of a longer member of this series, CCCCCl, have also been observed in the same discharge plasma. It was confirmed that the radical shows a 2Σ type spectral pattern. The rotational, fine, and hyperfine coupling constants have been determined. Ab initio calculations are now in progress to obtain more information on the electronic and geometrical structures for the radical. It is expected to obtain an insight into the effect of carbon chain length to the electronic and geometrical structures from a comparison between the results of CCCCCl and CCCl.

64

A2-02

Isotope Study of the CCO Radical in its 3Σ- Ground State by Microwave Spectroscopy

Kaori Kobayashi1 and Shuji Saito2 1 Graduate School of Science and Engineering, Tokyo Institute of Technology, Tokyo, Japan 2 Research Center for Development of Far-Infrared Region, Fukui University, 3-9-1 Bunkyo, Fukui 910-8507, Japan

Molecules with carbon chain structure have been one of the interesting topics in interstellar chemistry. The rotational spectrum of the CCO radical was first detected in the laboratory1 and subsequently detected in interstellar space.2 Extensive diode laser studies on many vibrational levels were carried out by Moazzen-Ahmadi and his co-workers.3 Therefore equilibrium rotational constant was obtained. However it is not sufficient to determine the molecular structure. In addition, signs of the 13C hyperfine structure constants were not established in the previous ESR study in matrix.4 In this study the isotopomers of CCO radical were observed by microwave spectroscopy to determine the rs structure and obtain spin densities. Source modulation microwave spectrometer was used to observe the spectra.5 CCO radical was produced by the dc discharge of 13CO (or C18O) and He (buffer gas) at the current of 20 mA. The cell had been cooled down to about 110 K during the measurement. Transitions due to 13CCO, C13CO, 13C13CO, and CC18O were measured and splitting due to 13C was resolved. Observed frequencies were analyzed by using conventional Hamiltonian including hyperfine structure. Detailed analysis and comparison with the CCO radical in matrix and the CCS radical will be given.

1 C. Yamada, S. Saito, H. Kanamori and E. Hirota, Astrophys. J. 290, L65 (1985). 2 M. Ohishi, H. Suzuki, S. Ishikawa, C. Yamada, H. Kanamori, W. M. Irvine, R. D. Godfrey, and N. Kaifu, Astrophys. J. 380, L39 (1991). 3 Z. Abusara, T. S. Solensen, and N. Moazzen-Ahamadi, J. Chem. Phys. 119, 9491 (2003) and references therein. 4 G. R. Smith and W. Weltner Jr., J. Chem. Phys. 62, 4592 (1975). 5 S. Saito and M. Goto, Astrophys. J. 410, L53 (1993).

65

A2-03

New Dispersed Fluorescence Spectra of Simple Halocarbenes in a Discharge Supersonic Free Jet Expansion

Chia-Shih Lin, Wei-Zhong Chang, Hui-Ju Hsu, and Bor-Chen Chang* Department of Chemistry, National Central University, Chung-Li 32054, Taiwan

We have successfully acquired new dispersed fluorescence spectra following the ~ ~ excitation of several A ← X vibronic bands of HCCl, DCCl, and CBr2 at visible wavelengths in a discharge supersonic free jet expansion using an intensified charge-coupled device (ICCD) detector. Due to the improvement of signal-to-noise ratios by a factor of ~ roughly 10, the new dispersed fluorescence spectra reveal more details of the X state vibrational structure in these molecules than previous reports. [1, 2] Dispersed fluorescence spectra of all four isotopomers (HC35Cl, HC37Cl, DC35Cl, and DC37Cl) of monochloromethylene were obtained. Complete vibrational parameters including fundamental frequencies, anharmonicities, and coupling constants were determined for the ~ HCCl/DCCl X 1A′ state. Furthermore, perturbations from the background triplet state

( a~3A′′ ) were clearly observed in the new dispersed fluorescence spectra, and therefore the ~ ~ singlet-triplet energy gap could be determined. Additionally, a couple of new A ← X vibronic bands were found in the laser excitation spectra of HCCl and DCCl. The new dispersed fluorescence spectrum of CBr2 was also recorded and analyzed. More vibrational structures of the CBr2 ground electronic state were determined.

[1] C.-W. Chen, T.-C. Tsai, and B.-C. Chang, Chem. Phys. Lett. 347, 73 (2001). [2] C.-L. Lee, M.-L. Liu, and B.-C. Chang, Phys. Chem. Chem. Phys. 5, 3859 (2003).

66

A2-04

Double-Resonance Spectroscopy on HCO and H2CO by Two-Color Resonant Four-Wave Mixing

Peter P. Radi, Marek Tulej, Gregor Knopp, Paul Beaud and Thomas Gerber

Paul Scherrer Institute, Department General Energy, CH-5232 Villigen, Switzerland

We report on Stimulated Emission Pumping (SEP) experiments on HCO in a low-pressure cell at ambient temperature by applying Two-Color Resonant Four-Wave

Mixing (TC-RFWM) [1]. The high sensitivity and selectivity of the method allows the unambiguous assignment of the double-resonance transitions observed in the (0,3,1) ~ rovibrational band of HCO on the electronic ground state X 2A'. By taking advantage of the thermally populated N-levels up to ~ 20, the determined rotational constants from 89 transitions yield structural information on the vibrationally excited formyl radical.

In addition, the initial TC-RFWM experiments on H2CO in the low pressure cell [2] are extended to investigations in a molecular beam environment. This work focuses on the near threshold dynamics of the dissociation of formaldehyde via the radical channel, i.e. H2CO →

HCO + H around 30340 cm-1.

[1] P. P. Radi, M. Tulej, G. Knopp, P. Beaud, T. Gerber, J. Raman Spectrosc. 34, 1037

(2003).

[2] P. P. Radi and A.P. Kouzov, J. Raman Spectrosc. 33, 925 (2002).

67

A2-05

Near Infrared Emission Spectra of HO2 and DO2

E. H. Fink1 and D. A. Ramsay2

1Physikalische Chemie, FB9,Bergische Universität-Gesamthochschule Wuppertal, D-42097 Wuppertal, Germany 2Steacie Institute of Molecular Sciences, National Research Council, Ottawa, Canada K1A 0R6

Near infrared emission spectra of HO2 and DO2 have been recorded in the region 8000 to

6000 cm-1 using a Fourier Transform spectrometer [1]. Rotational analyses of the 000-000 and other bands have been carried out and structures of the molecules in the ground and excited states determined. Most of the transitions are electric dipole in character but many magnetic dipole transitions have been seen as well as some very weak electric dipole transitions caused by spin-orbit coupling of the ground and excited states. Many perturbations have been seen and give information on neighbouring states.

[1] E. H. Fink and D. A. Ramsay, J. Mol. Spectrosc. 185, 304-324 (1997); ibid 216, 322-334

(2002)

68

A2-06

Cavity Ring Down Spectroscopy of CH, CH2, HCO and H2CO in a Premixed Flat Flame at both Atmospheric and Sub-atmospheric Pressure

R. Evertsen1, A. Staicu2, J.A. van Oijen1, N.J. Dam3, L.P.H. de Goey1 and J.J. ter Meulen3 1 Eindhoven University of Technology, Eindhoven, The Netherlands 2 National Institute for Laser Physics and Radiation Physics, Bucharest, Romania 3 University of Nijmegen, Nijmegen, The Netherlands

Absolute concentrations of CH, CH2, HCO and H2CO have been measured in a premixed flat flame by the use of Cavity Ring Down Spectroscopy (CRDS). At atmospheric pressure problems were encountered due to both the narrow spatial distribution of these species close to the burner surface and the occurrence of thermal deflection of the laser beam. As a result only the distribution of CH could be completely observed [1]. The distributions of

CH2 and HCO could be measured only partly [2], whereas H2CO was too close to the burner surface to be detectable in the atmospheric flame. In a low-pressure set up the entire spatial distributions of all species could be measured by CRDS at 200 mbar. In addition, signals have been observed which may be attributed to HCN. The rotational flame temperature was derived from the Boltzmann distribution as obtained from the CH spectrum. The results are compared to modeling calculations using GRI-Mech 2.11 and 3.0. The calculated concentrations are in good agreement with the experimental results. However, at atmospheric pressure deviations are present between the calculated and observed position of the CH distribution relative to the burner surface and between the calculated and observed temperature at the position of the maximum CH density. The deviations are verified by an analysis of the effects of experimental inaccuracies and are attributed to the applied reaction mechanism in the calculations. Also for the low-pressure burner deviations between the positions of the distributions of the observed species were observed.

[1] R. Evertsen, J.A. van Oijen, R.T.E. Hermanns, L.P.H. de Goey and J.J. ter Meulen, Comb.Flame 132, 34 (2003) [2] R. Evertsen, J.A. van Oijen, R.T.E. Hermanns, L.P.H. de Goey and J.J. ter Meulen, Comb.Flame 135, 57 (2003)

69

A2-07

Rotation-vibration Motion of Pyramidal XY3 Molecules Described in the

Eckart Frame: Theory and Application to NH3

Sergei N. Yurchenko,1 Miguel Carvajal,2 Per Jensen,3 Hai Lin,4 and Walter Thiel 4 1Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A OR6 2Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Avda. de las FF.AA. s/n, Universidad de Huelva, 21071, Huelva, Spain 3FB C - Theoretische Chemie, Bergische Universität, D-42097 Wuppertal, Germany 4Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany

We present a new model for the rotation-vibration motion of pyramidal XY3 molecules, based on the Hougen-Bunker-Johns approach. Inversion is treated as a large amplitude motion, while the small-amplitude vibrations are described by linearized stretching and bending coordinates. The rotation-vibration Schrödinger equation is solved

14 variationally. We report three applications of the model to NH3 using an analytic potential function derived from high-level ab initio calculations [1]. These applications address the J=0 vibrational energies up to 6100cm-1, the J ≤ 2 energies for the vibrational ground state and the

+ ν2, ν4, and 2ν2 excited vibrational states, and the J ≤ 7 energies for the 4ν2 vibrational state.

We demonstrate that also for four-atomic molecules, theoretical calculations of rotation-vibration energies can be helpful in the interpretation and assignment of experimental, high-resolution rotation-vibration spectra.

This work is supported by the European Commission through contract no.

HPRN-CT-2000-00022 "Spectroscopy of Highly Excited Rovibrational States".

[1] H. Lin, W. Thiel, S. N. Yurchenko, M. Carvajal, and P. Jensen, J. Chem. Phys. 117,

11265 (2002).

70

A2-08

Resonance-enhanced Multiphoton Ionization Spectroscopy of CH3 and CD3 . Two-photon Absorption Selection Rules and Rotational Line Strengths of the v3- and v4-Active Vibronic Transitions

Kuo-mei Chen Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC

To explore the possibility of K-level resolved, 2+1 resonance-enhanced multiphoton

ionization (REMPI) processes of the methyl radical, the two-photon absorption selection

1 1 rules and rotational line strengths of the 30 and 40 vibronic bands of the transition

2 ~ 2 np A2′′ ← X A2′′ (n = 3 or 4) were reported. Stringent selection rules, which were

imposed upon these two-photon transitions, are the initial K ′′ = 3p (p = 0, 1, 2,..),

∆K = ±2, ∆U = ±3 and ∆N = 0, ±1, ± 2 (O, P, Q, R and S branches). The previously

2 assigned 22 vibronic band of the methyl radical should be studied by the REMPI with a

better spectral resolution and analyzed by the newly derived two-photon absorption

selection rules and rotational line strength formulas.

71

A2-09

The Vibration-Rotation Emission Spectra of Gaseous ZnH2 and ZnD2

Alireza Shayesteh1, Dominique R. T. Appadoo1, Iouli Gordon2, and Peter F. Bernath1,2 1Department of Chemistry, University of Waterloo, Waterloo, ON, N2L 3G1, Canada 2Department of Physics, University of Waterloo, Waterloo, ON, N2L 3G1, Canada

High resolution infrared emission spectra of gaseous ZnH2 and ZnD2 have been recorded with a Fourier transform spectrometer. The molecules were generated in an emission source that combines an electrical discharge with a high temperature furnace. The

-1 vibration-rotation emission spectra of ZnH2 and ZnD2 were recorded in the 1200-2200 cm region at an instrumental resolution of 0.01 cm-1. The antisymmetric stretching fundamental

64 64 -1 -1 bands, 001-000, of ZnH2 and ZnD2 were observed near 1889.4 cm and 1371.6 cm , respectively, and for the minor isotopes of zinc, 66Zn and 68Zn, the band origins were shifted

-1 by approximately 1-2 cm . Preliminary analysis of the spectra resulted in r0 values of

64 64 1.535271(1) Å and 1.531833(9) Å for ZnH2 and ZnD2, respectively. Several hot bands of

ZnH2 involving ν1, ν2 and ν3 have also been observed, and analysis of these bands will lead to an equilibrium structure (re) for ZnH2. This work is a continuation of our search for new metal dihydrides that has so far led to the detection of BeH2 [1, 2] and MgH2 [3].

[1] P.F. Bernath, A. Shayesteh, K. Tereszchuk and R. Colin, The Vibration-Rotation Emission

Spectrum of Free BeH2, Science 297, 1323-1324 (2002). [2] A. Shayesteh, K. Tereszchuk, P.F. Bernath and R. Colin, Infrared Emission Spectra of

BeH2 and BeD2, J. Chem. Phys. 118, 3622-3627 (2003). [3] A. Shayesteh, D.R.T. Appadoo, I. Gordon, and P.F. Bernath, The Vibration-Rotation

Emission Spectrum of MgH2, J. Chem. Phys. 119, 7785-7788 (2003).

72

A2-10

Identification and Characterization of Two New Electronic Transitions of the FeH Radical in the Infrared

Walter J. Balfour,1 John M. Brown,2 and Lloyd Wallace3

1Department of Chemistry, University of Victoria, Victoria BC, V8W 3P6, Canada 2Department of Physical and Theoretical Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom 3National Optical Astronomy Observatories, P.O. Box 26732, Tucson, AZ 85719, U.S.A.

Transition metal monohydrides are notorious for the spectroscopic challenges they present. Their spectra are mostly many-line and complex. Their electronic states are often of high orbital angular momentum and multiplicity. The FeH radical is a typical example.

Since the identification of its 989.6 nm system as 4∆ - X4∆ [1], steady progress has been made in the location and characterization of predicted low-lying states in the sextet manifold [2].

However, several low-lying quartet states are also expected. We wish now to report the identification through rotational analysis of two FeH electronic systems in the infrared between 6000 and 7500 cm-1. We classify these electronic transitions as E 4Π - X 4∆ and G

4Π - E 4Π. Numerous rotational perturbations are evident in the spectra. Details of the analyses will be presented. Prominent FeH features are present in sunspot umbral spectra

[3].

[1] J. G. Phillips, S. P. Davis, B. Lindgren and W. J. Balfour, Astrophys. J. Suppl. Ser. 65, 721 (1987). [2] C. Wilson, H. M. Cook and J. M. Brown, J. Chem. Phys. 115, 5943 (2001). [3] L. Wallace and K. Hinckle, Astrophys. J. 559, 424 (2001).

73

A2-11

Detection of the Electronic Spectra of FeCl2 and CoCl2 in the Gas Phase

Stephen H. Ashworth,1 Thomas D. Varberg,2 Philip J. Hodges,3 and John M. Brown,3

1School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom 2 Department of Chemistry, Macalester College, 1600 Grand Avenue, St Paul, MN 55105, USA 3Department of Physical and Theoretical Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom

The band systems of FeCl2 at 288 nm and of CoCl2 at 310 nm have been recorded at high resolution by laser excitation spectroscopy. These results confirm earlier observations at low resolution by DeKock and Gruen [1] but provide much more structural information. The molecules were formed in a high-temperature reaction between HCl and the metal; the sample was cooled to a rotational temperature of about 10K in a subsequent free-jet expansion.

For both spectra, an excited state vibrational progression with an interval of approximately 200 cm-1 has been identified; the interval has been tentatively assigned to the symmetric stretching vibration. Rotational analyses of selected bands reveal the Ω s the lower and upper states involved in the transitions. The analyses also provide rotational constants and vibrationally averaged bond lengths. The spectra are consistent with a linear structure [2]. Dispersed fluorescence studies show progressions in the ground state symmetric stretching -1 -1 vibration ν1 (353 cm for FeCl2 and 362 cm for CoCl2). These values are very similar to those determined for other transition metal dichlorides [3]. There appears to be a marked reduction in this vibrational wavenumber on excitation to the upper electronic states.

[1] C.W. DeKock and D.M. Gruen, J. Chem. Phys. 44, 4378 (1966). [2] S.H. Ashworth, P.J. Hodges and J. M. Brown, Phys. Chem. Chem. Phys. 4, 5923 (2002). [3] F.J. Grieman, S.H. Ashworth and J.M. Brown, J. Chem. Phys. 92, 6365, (1990).

74

A2-12

Free Radicals in the Reaction Products of Zr with Methane: the Electronic Spectra of ZrC and ZrCH

A.J. Merer1, J.R.D. Peers1,2 and S.J. Rixon1,3 1Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, B.C., Canada V6T 1Z1 2Present address: Creo Inc., 3755 Willingdon Avenue, Burnaby, B.C., Canada V5G 3H3 3Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C., Canada V6T 1Z1

Two new free radicals have been observed by laser-induced fluorescence, following the reaction of laser-ablated zirconium with methane under supersonic free jet conditions. ZrC dominates at small CH4 concentrations (~1% in helium), while ZrCH is found at higher concentrations (~8%). Both have very complicated band systems in the 520−670 nm region. The complexity of the ZrC spectrum occurs because the highest occupied molecular orbitals, 11σ and 12σ (Zr 5sσ and C 2pσ) are nearly degenerate, with two electrons available to fill them. The ground state, X3Σ+, arises from the configuration (11σ)1 (12σ)1, but low-lying 1Σ+ states, corresponding to the other possible arrangements of these two electrons, are observed at 187.83, 1846 and 2463 cm−1. Evidence for the σσ′ electron configuration of the 3Σ+ ground state comes from the small value of the spin-spin parameter λ (0.514 cm−1), and the wide hyperfine widths of the 91ZrC lines (nearly 0.2 cm−1). These show that one of the electrons is in an orbital derived from the Zr 5sσ atomic orbital, so that the other electron must also be in a σ orbital, presumably C 2pσ. Internal hyperfine perturbations occur in the 3 + 91 Σ ground state of ZrC, where the hyperfine levels of the F1 and F3 electron spin components perturb each other with selection rules ∆N = 0, ∆J = ±2. The mechanism is second order, where ∆N = 0, ∆J = ±1 matrix elements of the Fermi contact operator mix both the F1 and F3 electron spin components with the F2 component. The excited electronic states near 16000 cm−1 represent promotion of one or other of the σ electrons to the 6π m.o. (Zr 4dπ); four close-lying (and strongly-interacting) states arise, two 3Π and two 1Π. Further perturbations arise from higher vibrational levels of ‘dark’ electronic states at lower energy. Like the isoelectronic ZrN,[1] ZrCH has a 2Π − X2Σ+ transition near 15000 cm−1. Dispersed fluorescence studies of bands of this system have mapped the vibrational structures of the ground states of ZrCH and ZrCD, while high resolution rotational analyses give the bond lengths as r(Zr-C) = 1.831 Å, r(C-H) = 1.087 Å. Although the ground state is well understood, the vibrational assignments of many of the observed levels of the 2Π excited state remain unclear. Rotational analyses of about ten sub-bands each of ZrCH and ZrCD have given the Zr isotope shifts and the upper state P values (where P = Λ + l + Σ), while 13C shifts have been obtained for the strongest bands of ZrCH. It appears that there is strong vibronic 2 2 1 coupling with both a Σ and a ∆ state, in order to account for the intensity of the 2 0 band and its comparatively large Renner-Teller splitting, together with the unexpectedly small values of the apparent spin-orbit coupling parameter and the Zr-C stretching frequency. [1] H. Chen, Y. Li, D.K-W. Mok and A.S-C. Cheung, J. Mol. Spectrosc. 218, 213 (2003).

75

A2-13

The Bending Vibrational Levels of Acetylene Cation: A Case Study of the Renner-Teller Effects with Two Degenerate Bending Vibrations

Sheunn-Jiun Tang,1,2 Yung-Ching Chou,1 Jim Jer-Min Lin,1,3 and Yen-Chu Hsu1,2 1Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan, R. O. C. 2Department of Chemistry, National Taiwan University, Taipei 106, Taiwan, R. O. C. 3Department of Applied Chemistry, National Chiao Tung University, Hsin-Chu, Taiwan 300, R. O. C.

Thirty-eight vibronic levels of the acetylene cation, with v4=0-6, v5=0-2 and K=0-3, lying at energies of 0−3520 cm-1 above the zero-point level, have been recorded at rotational resolution by the method of 1+1′ two-color pulsed-field ionization zero-kinetic-energy (PFI-ZEKE) photoelectron spectroscopy. In this work, single ro-vibrational levels have been chosen from the V4K1,2, V5K1, 11V2K1 and 21V4K0 levels of the à state of C2H2 as the intermediates of the two-color excitation processes. (V refers to the trans-bending vibration). + Among the observed vibronic levels of C2H2 , seven trans-bending levels (v4=0-3, K=0-3) are in fairly good agreement with results previously reported by Pratt et al.[1] In this study, the Renner-Teller effect, the vibrational anharmonicity, and the vibrational l-type doubling of both the trans- and cis-bending vibrations were included in the spectral analysis. For the lowest 14 observed vibronic levels with v4 + v5 ≤ 2, (though not including ± the two components of v4=0, v5=1, K=0 ) a least squares fit using 16 parameters gave an r.m.s. -1 deviation of 0.35 cm . The sign of є5 could be determined. For the higher vibronic levels, an additional parameter, r45, was included in the fit to allow for the Darling-Dennison resonance between the two bending manifolds. With these 17 parameters, about 61% and 58% of the v4 + v5 =3 and v4 + v5 =4 polyads, respectively, could be assigned. In the overall fit -1 to 32 vibronic levels with v4 + v5 ≤ 4, an r.m.s. deviation of 0.45 cm was obtained using 17 parameters. It was at first surprising to find that among the three observed v4 = 1, v5 = 2, Σu levels, two belong to Hund's case (a) and one to Hund’s case (b), but this result is in fact in good agreement with the theoretical predictions. [1] S. T. Pratt, P. M. Dehmer, and J. L. Dehmer, J. Chem. Phys. 99, 6233 (1993).

76

A2-14

High Resolution Spectroscopic Studies of Vibrational States in the Triplet Potential of Acetylene

K. Yoshida, and H. Kanamori

Department of Physics, Tokyo Institute of Technology Ohokayama Megoro-ku Tokyo Japan

Since acetylene in the lowest triplet state (T1) was predicted that there are three local minima at cis-, trans-, and vinylidene configurations by theoretical calculations, an isomerization reaction among those configurations has been paid a lot of attentions. We have observed an electronic transition between the T2 - T1 potential energy surface at the cis-bent configuration around 7400 cm-1 region by using high resolution near-IR diode laser kinetic spectroscopy combined with a pulsed mercury photo-sensitized reaction. By now 0-0 band of

C2H2, C2HD and C2D2 have been observed in Doppler limited resolution and rotational analysis have been performed. However, vibrational excitation in the bending modes is essentially important for the cis-trans isomerization. It is very promising to detect vibrationally excited states in the mercury photo-sensitized reaction because most of the excess energy is transferred into the internal vibrations of the lowest triplet electronic state, especially in the bending mode to compensate a drastic change from the linear to cis-bent structure. This means that a nascent product of the reaction is highly vibrationally excited beyond cis-trans barrier in the T1 potential. That is the cis-trans isomerization state which we are looking for.

In the experiment searching for a hot band, 1-1 band of C2H2 and C2D2 were observed by the kinetic spectroscopy. The hot band signals were discreminated from the stronger and slower peakes of the 0-0 band by setting a shorter gate after a pulsed excitation. A thousand of new peaks were assignd to electric transitions between vibrating triplet asymmetric rotors, which shows strong Colioris interraction. The vibrational state observed is assigned to symmetric cis-bending mode. An effect of the vibrational excitation on the T1 and T2 potential will be discussed.

77

A2-15

Experimental and Theoretical Studies On Rydberg States of H2CS in the Region 130−220 nm

I-Feng Lin, Fendi Kurniawan, and Su-Yu Chiang National Synchrotron Radiation Research Center, Hsinchu, Taiwan

Absorption Spectrum of H2CS in the region 130−220 nm was recorded with a continuously tunable light source of synchrotron radiation. Unstable H2CS was prepared by thermally cracking c-C3H6S at temperatures above 750°C. The measurements were performed under continuously flowing condition with a dual beam photoabsorption system on the high-flux beamline at the National Synchrotron Radiation Research Center (NSRRC) in

Taiwan. Observation of four absorption systems of H2CS that correspond to transitions n → 3s,

3py, and 3pz, and π → π in the region 180−220 nm is consistent with previous report; our spectrum shows improved resolution in the π → π absorption spectrum. Absorption spectrum of H2CS in the region 130−180 nm is reported for the first time. Theoretical calculations using time-dependent density functional theory (TD-DFT) with different basis sets were also made to predict vertical excitation energies and oscillator strengths. Transitions to Rydberg states associated with excitation to 4s−6s, 4py−5py and 4pz−5pz are assigned based on effective quantum numbers and comparison with predicted vertical excitation energies. Thermal products of c-C3H6S and intensity variation of their absorption bands at different temperatures will also be discussed.

78

A2-16

Infrared Spectra of Neutral and Ionic SO2H2 Species Trapped in Solid Neon

Marilyn E. Jacox and Warren E. Thompson Optical Technology Division, National Institute of Standards and Technology Gaithersburg, Maryland 20899-8441, U. S. A.

When a Ne:H2:SO2 = 600:10:1 mixture is codeposited at 4.2 K with a beam of neon atoms that have been excited in a microwave discharge, new absorptions of hydrogen-containing products are observed. Among the products are the recently identified species cis-HOSO and HSO2, as well as isomers of S(OH)2 and of its cation. In other experiments in which the neon atoms are not excited in the discharge but in which the SO2 is excited by 254 nm radiation, isomers of uncharged S(OH)2 and of HSOOH appear. Isotopic substitution studies and density functional calculations support the infrared identifications.

79

A2-17

Polarized IR Spectrum of Matrix-Isolated Propargyl Radicals and

Detection of HC≡CH-CH2OO

Evan B. Jochnowitz,1 Xu Zhang,1 Mark R. Nimlos,1,2 Mychel Elizabeth Varne,3 John F. Stanton,3 and G. Barney Ellison1

1 Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215, USA. Email: [email protected]

2 National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401, USA Email: [email protected]

3 Institute for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, TX 78712, USA. Email: [email protected]

Beams of the propargyl radical have been produced by thermal dissociation of

HC≡C-CH2Br and HC≡C-CH2CH2ONO in a hyperthermal nozzle. The production of the

HC≡C-CH2 radical was verified with a photoionization mass spectrometer: HC≡C-CH2 + + hω118.2 nm → HC≡C-CH2 (m/z 39). Samples of propargyl were deposited on a 10 K cold CsI window and the polarized infrared absorption spectrum of the propargyl radical was collected. The linear dichroism was measured with photooriented samples to yield experimental polarizations of the vibrational modes. We have detected nine of the twelve fundamental vibrational modes of propargyl: Γvib(HC≡C-CH2) = 5a1 ⊕ 3b1 ⊕ 4b2. The ˜ 2 –1 experimental HC≡C-CH2 (X B1) frequencies (cm ) and polarizations follow: a1 modes —

3308, 3028, 1935, 1369, 1061; b1 modes — 686, 483; b2 modes — 1017, 620. When beams of HC≡C-CH2 and O2 are co-deposided at 10 K, a chemical reaction is observed to produce ˜ 2 ˜ 2 the propargyl peroxyl radical: HC≡C-CH2 (X B1) + O2 → HC≡C-CH2OO (X A”). ˜ 2 The experimental frequencies of some vibrational modes for HC≡C-CH2OO (X A”) are obtained.

[submitted to J. Phys. Chem. A, May, 2004]

80

A2-18

Recent Progress in FTIR and DFT Studies on the Vibrational Spectra and Structures of Group IV Clusters

R. Cardenas, S.A. Bates, D.L. Robbins, C.M.L. Rittby and W.R.M. Graham Department of Physics and Astronomy, TCU, Fort Worth, Texas, USA

The fundamental vibrations and structures of pure and mixed clusters of C, Si, and Ge are of interest in a wide variety of applications ranging from stellar and interstellar chemistry to semiconductor properties and manufacture. Fourier transform infrared measurements coupled with density functional theory (DFT) calculations have resulted in the identification of vibrational fundamentals of novel carbon chains with single atoms of Si, Ge, and various transition metals such as Ti, Fe, and Mn bonded to the terminal carbons. Structures and identifications are confirmed by comparison with observed frequencies and with extensive measurements of 13C isotopic shifts.

81

A2-19

Photochemistry of HI-Allene Complexes in Argon Matrices

Cailin Delaney, Justin Clar, Jodi Cohen and Samuel A. Abrash Department of Chemistry, University of Richmond, Richmond, VA, 23173, USA

HI-allene complexes, and their isotopic variants, including DI-allene, HI-perdeuteroallene, and DI-perdeuteroallene, were photolysed in cryogenic Ar matrices. Data on growth of products as a function of photolysis time was collected, and ab initio calculations of the vibrational frequencies of potential products were done. The results are discussed in light of potential models that can account for the product branching ratios of these weakly bound complexes.

82

A2-20

Decelerating OH and NH Radical Beams

S.Y.T. van de Meerakker, N. Vanhaecke, and G. Meijer

Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany and FOM Institute for Plasmaphysics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands

During the last few years, great experimental progress has been made in manipulating molecules with electric fields. Arrays of time-varying, inhomogeneous electric fields have been used to reduce in a stepwise fashion the forward velocity of molecules in a beam. With this so-called ‘Stark-decelerator’, the equivalent of a LINear Accelerator (LINAC) for charged particles, one can transfer the high phase-space density that is present in the moving frame of a pulsed molecular beam to a reference frame at any desired velocity; molecular beams with a computer- controlled (calibrated) velocity and with a narrow velocity distribution, corresponding to sub-mK longitudinal temperatures, can be produced [1].

Using a proto-type Stark decelerator we have been able to trap ND3 molecules in an electrostatic trap [2] at temperatures of around 25 mK, and to confine bunches of slow molecules in a storage ring [3]. In principle, this method can be extended to any polar molecule, but because of their special molecular properties and chemical relevance, radical species like OH, CH and NH are considered prime candidates.

We will report on a scaled up version of the Stark-decelerator and molecular beam machine that has just become operational, and that is able to capture a much larger fraction of the original molecular beam. It has been used to produce decelerated beams of ground-state OH and electronically excited (metastable) NH radicals. The NH radical is particularly interesting, as an optical pumping scheme enables the accumulation of decelerated bunches of slow NH radicals, either in a magnetic or in an optical trap [4].

[1] H.L. Bethlem and G. Meijer, Int. Rev. Phys. Chem. 22, 73 (2003).

[2] H.L. Bethlem et al., Nature (London) 406, 491 (2000); H.L. Bethlem et al., Phys. Rev. A 65, 053416 (2002).

[3] F.M.H. Crompvoets et al., Nature (London) 411, 174 (2001).

[4] S.Y.T. van de Meerakker et al., Phys. Rev. A 64, 041401(R) (2001).

83

A2-21

Inter-bonds Crossing Dipole Moment and Stretching Vibrational Bands Intensities of the Group V Hydrides

Shui-Ming Hu, An-Wen Liu, Sheng-Gui He, Jing-Jing Zheng, Hai Lin and Qing-Shi Zhu Laboratory of Bond Selective Chemistry, University of Science and Technology of China, Hefei 230026, P.R.China

The dipole moment stimulated by a vibrating bond in a polyatomic molecule was used to be treated as a bond dipole, whose direction was considered to be along the vibrating bond.

However, the full polynomial expansion of the multi-dimensional dipole moment surface of a polyatomic molecule, for instance, XH3 type hydrides, should also include the inter-bond crossing terms. The three-dimensional X-H stretching DMSs of the group V hydrides are calculated by the density functional theory method. Together with the effective Hamiltonian model, the stretching vibrational bands intensities of these molecules are calculated and also compared with the experimental results what are derived from the infrared absorption spectra recorded by a Fourier-transform spectrometer and those values available in literatures. The inter-bonds crossing terms in the DMS expansion are found to be important to the overtone bands intensities and dominant for those combination bands. The contribution from different terms to the stretching vibrational bands intensities of such a hydrides are discussed.

84

B1-01

Crossed Molecular Beam Studies of Radical-Radical Reactions: 3 O( P) + C3H5 (Allyl)

G. Capozza,1 F. Leonori, 1 E. Segoloni, 1 N. Balucani, 1 D. Stranges,2 G. G. Volpi, 1 and P. Casavecchia1 1Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy 2Dipartimento di Chimica, Universita` di Roma "La Sapienza", 00185 Roma, Italy

The Crossed Molecular Beams (CMB) scattering technique with "universal" electron-impact (EI) mass-spectrometric detection and time-of-flight (TOF) analysis has been central in the development of our understanding of reaction dynamics [1]. While reactive differential cross sections (DCSs) have been measured using this technique for a great variety of atom (radical) + molecule reactions over the past 40 years [1], very little has been done on radical-radical reactions. This is mainly due to the difficulty of generating beams of two radical species of sufficient intensity to carry out angular and velocity distribution measurements. We record only the pioneering study in 1997 by Lee's group [2] using the CMB method, aimed at determining DCSs for a radical-radical reaction: C(3P) + propargyl 3 (C3H3) was investigated using a pulsed supersonic C( P) atom beam obtained by laser ablation of graphite and a pulsed supersonic beam of propargyl radicals obtained by laser photolysis of propargyl bromide. From TOF measurements at a few selected angles, the lab angular distribution of the C4H2 product was obtained and the center-of-mass DCS derived. 3 Product rovibrational distributions were determined by LIF detection for O( P)+ND2 in 3 crossed beams [3] and very recently for the reactions O( P) + propargyl (C3H3) and allyl (C3H5) radicals in unskimmed pulsed jets [4]. In order to investigate the dynamics of radical-radical reactions using the CMB technique with "continuous" mass spectrometric detection it is desirable to use "continuous" supersonic beams of the radical species, so that one can measure readily the product angular distributions by modulating one of the two beams for background subtraction. Then, from also product TOF distribution measurements, one can derive the double reactive DCS in the center-of-mass system. In our laboratory we are generating since a number of years "continuous" supersonic beams of a variety of simple radicals [O(3P,1D), N(4S,2D), C(3P,1D), Cl(2P), OH(2Π), and CN(2Σ+)] by using a high-pressure radio-frequency discharge quartz nozzle beam source [1]. Very recently, we have also developed a radical source, based on the flash pyrolysis in a SiC nozzle, for generating "continuous" supersonic beams of alkyl radicals (CH3, C2H5, C3H3, C3H5, etc.). The availability of these sources for producing "continuous" supersonic beams of a variety of radicals, coupled with a sensitive CMB apparatus exploiting the "soft" electron impact ionization for product detection [5], is permitting us to undertake the investigation of the dynamics of a variety of radical-radical reactions. Here we report on the first measurements of product angular and velocity distributions for the radical-radical reaction 3 O( P) + allyl (C3H5), of great relevance in combustion chemistry.

[1] P. Casavecchia, Rep. Prog. Phys. 63, 355 (2000), and references therein. [2] R. I. Kaiser, W. Sun, A. G. Suits, and Y. T. Lee, J. Chem. Phys. 107, 8713 (1997). [3] D. Patel-Misra, D. G. Sauder, and P. J. Dagdigian, J. Chem. Phys. 95, 955 (1991). [4] S. -K. Joo, L.-K. Kwon, H. Lee, and J.-H. Choi, J. Chem. Phys. 120, 7976 (2004). [5] G. Capozza, E. Segoloni, F. Leonori, G. G. Volpi, P. Casavecchia, J. Chem. Phys. 120, 4557 (2004).

85

B1-02

The Dynamics of Prototype Insertion Reactions: Crossed Beam Experiments versus Quantum and Quasiclassical Trajectory Scattering Calculations on Ab Initio Potential Energy Surfaces for 1 2 C( D) + H2 and N( D) + H2

N. Balucani,1 G. Capozza, 1 E. Segoloni, 1 L. Cartechini, 1 R. Bobbenkamp,1 P. Casavecchia1 L. Bañares,2 F. J. Aoiz,2 P. Honvault,3 B. Bussery-Honvault,3 J.-M. Launay3 1Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy 2Departamento de Química Física, Universidad Complutense, E-28040 Madrid, Spain 3PALMS/SIMPA-UMR 6627 du CNRS ,Université de Rennes I, 35042 Rennes, France

In order to deepen our understanding of the dynamics of insertion reactions [1,2], we 1 have recently extended our crossed beam investigations beyond O( D)+H2 to two other 2 1 prototypical reactions, N( D)+H2 and C( D)+H2, which occur on a PES with a deep well associated with the strongly bound species NH2 and CH2, respectively. We exploit the capability of generating continuous supersonic beams of N(2D) and C(1D) atoms [1,2]. We 1 have studied C( D)+H2 at two collision energies, Ec=1.86 and 3.8 kcal/mol, and the isotopic 1 variant C( D)+D2 at Ec=3.6 kcal/mol by measuring product angular and velocity distributions in crossed beam experiments with mass spectrometric detection and time-of-flight analysis. The results at Ec=1.86 kcal/mol, which were previously compared with statistical predictions [2], have been compared with exact quantum-mechanical (QM) as well as quasiclassical trajectory (QCT) scattering calculations carried on a new ab initio PES [3]. For the higher Ec 1 of 3.8 kcal/mol and for C( D)+D2 the experimental results have been compared with the results of QCT calculations. 2 Following on studies of the isotopic variant N( D)+D2 at Ec=15.9 and 21.3 kJ/mol, and comparisons with QCT calculations on an accurate ab initio ground state 12A" PES [4], we 2 have investigated the reaction N( D) + H2(j=0-3) → NH + H, at Ec=15.9 kJ/mol and compared the results with those of QM and QCT calculations. The good agreement between QM predictions and experiment assess the quality of the ab initio ground state PES. Small, but significant discrepancies between QCT and QM calculations suggest the occurrence of quantum effects - tunneling through the combined potential and centrifugal barrier, similarly to what seen for abstraction reactions [6]. Acknowledgments: R. Bobbenkamp acknowledges a fellowship within the EC Research Training Network REACTION DYNAMICS (contract HPRN-CT-1999-00007).

[1] P. Casavecchia, N. Balucani, G. G. Volpi, Annu. Rev. Phys. Chem. 50, 347 (1999); P. Casavecchia, Rep. Prog. Phys. 63, 355 (2000); K. Liu, Annu. Rev. Phys. Chem. 52, 139 (2001); X. Liu, J. J. Lin, S. Harich, G. C. Schatz, X. Yang, Science 289, 1536 (2000). [2] Bergeat, L. Cartechini, N. Balucani, G. Capozza, L.F. Phillips, P. Casavecchia, G.G. Volpi, L. Bonnet, J.-C. Rayez, Chem. Phys. Lett. 327, 197 (2000). [3] B. Bussery-Honvault, P. Honvault and J. M. Launay, J. Chem. Phys. 115, 10701 (2001). [4] N. Balucani, M. Alagia, L. Cartechini, P. Casavecchia, G.G. Volpi, L.A. Pederson. G.C. Schatz, J. Phys. Chem. A 105, 2414 (2001). [5] P. Honvault and J. M. Launay, J. Chem. Phys. 111, 6665 (1999); ibid. 114, 1057 (2001). [6] N. Balucani, L. Cartechini, G. Capozza, E. Segoloni, P. Casavecchia, G. G. Volpi, F. J. Aoiz, L. Banares, P. Honvault, J.-M. Launay, Phys. Rev. Letters 89, 013201-1 (2002); and in preparation.

86

B1-03

Photodissociation Dynamics of Pyridine and C6HxF6-x (x=1~4) at 193 nm

Ming-Fu Lin,1 Yuri A. Dyakov,1 Sheng-Hsien Lin, 1,2 Yuan T. Lee,1,2 and Chi-Kung Ni1* 1Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 2Chemistry Department, National Taiwan University, Taipei, Taiwan

Photodissociation of pyridine and F substituted benzenes, C6HxF6-x (x=1~4), at 193 nm were studied separately using multimass ion imaging techniques. Photofragment translational energy and dissociation rate were measured. Five dissociation channels were observed in the photodissociation of pyridine, including the H atom elimination, C5NH5→ C5NH4 + H, and four ring opening channels, C5NH5→ C4H4 + HCN, C5NH5→ C3H3 + C2NH2, C5NH5→

C3NH + C2H4, C5NH5→ C4NH2 + CH3. Isotope substituted pyridine, 2,6, d2-pyridine, was also studied. The observation of various D atom substituted fragments indicates the H and D atom exchange prior to dissociation. Combination of experimental results and ab initio calculation provides the possible fragment structures and dissociation mechanism.

Photodissociation of F substituted benzenes shows HF elimination is the major channel. Small amount of photofragments corresponding to H atom eliminations were also observed.

Dissociation rate and fragment translational energy distribution suggest that HF elimination reactions occur in the ground electronic state. The potential energy surface obtained from ab initio calculations and the dissociation rate from RRKM calculation indicates that the four-center reaction in the ground electronic state is the major dissociation mechanism for the HF eliminations.

87

B1-04

State-to-state Photodissociation Dynamics of OH Radical via the A2Σ+ State 3 and Fine-structure Distributions of the O( PJ) Product

Weidong Zhou, Yan Yuan, and Jingsong Zhang Department of Chemistry, University of California Riverside, CA 92521 U.S.A.

OH radial is a prototypical open-shell diatomics. Photo-predissociation of OH via the A2Σ+ state serves as a model system for studying various non-adiabatic processes. Predissociation of A2Σ+ results from its crossings and spin-orbit couplings with three

4 - 2 - 4 3 2 repulsive states ( Σ , Σ , and Π, which correlate with the O( PJ) + H( S) products). At larger internuclear distances, these three repulsive states interact with each other via non-adiabatic couplings (spin-orbit and Coriolis interactions), and at the largest separations, non-adiabatic processes such as asymptotic spin–orbit interactions can also affect the 3 outcomes of photodissociation. The fine-state populations of the O( PJ) product are controlled by the non-adiabatic interactions among these electronic states along the dissociation coordinate, and they in turn can provide a sensitive probe of the dissociation dynamics. In this work, the photo-predissociation dynamics of rotational states (N') of OH (A2Σ+, 2 2 + 3 2 v' = 3 and 4), OH (X Π, v'', N'') + hν → OH (A Σ , v', N') → O( PJ) + H( S), is studied using the high-n Rydberg atom time-of-flight (HRTOF) technique. Spin-orbit branching fractions 3 of O( PJ=2,1,0) are measured: 0.676 ± 0.010:0.138 ± 0.013:0.186 ± 0.017 for N' = 0 in v' = 3 and 0.873 ± 0.026:0.102 ± 0.028:0.025 ± 0.005 for N' = 0 in v' = 4, in excellent agreement with the recent theory. While OH A2Σ+ v' = 3 predissociates predominantly via a single 4Σ- state, v' = 4 decays via the 4Σ-, 2Σ-, and 4Π states, and interferences of these dissociation 3 pathways strongly influence the O( PJ) fine-structure distributions. A bond dissociation -1 energy D0(O-H) = 35565 ± 30 cm is directly determined in the photodissociation experiment.

88

B1-05

Molecular Beam Studies of the Photolysis of 2-Chloro-2-butene and the Subsequent Dissociation of the 2-Buten-2-yl Radical

L. R. McCunn,1 J. L. Miller,1 M. J. Krisch,1 Y. Liu,1 L. J. Butler,1 and J. Shu 2 1The University of Chicago, Chicago, IL, U.S.A. [email protected] 2Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A.

This work investigates the unimolecular dissociation of the 2-buten-2-yl radical. Crossed laser-molecular beam studies of 2-chloro-2-butene produce the 2-buten-2-yl radical in the initial photolytic step. Our experiments disperse 2-buten-2-yl radicals by translational, and hence internal, energies. Dispersing chlorine atoms from the precursor molecule allows us to determine the velocity imparted in the initial C-Cl fission process and to assign an internal energy distribution to the nascent 2-buten-2-yl radicals. We then measure velocity distributions of products from unimolecular dissociation of the radical in order to determine relevant energy barriers to dissociation.

The 2-buten-2-yl radical is one of five straight-chain isomers of C4H7. G3//B3LYP calculations have characterized the relative energies and isomerization barriers of the five isomers, as well as the dissociation energies and barriers for possible unimolecular dissociation reactions of each isomer. Our interest in the 2-butenyl radical lies in its three competing reaction pathways: C-C fission to form CH3 + propyne, C-H fission to form H + 1,2-butadiene and C-H fission to produce H + 2-butyne. Our experimental results show that 193 nm photolysis of 2-chloro-2-butene results in two primary dissociation channels, C-Cl bond fission and HCl elimination. C-Cl bond fission is the dominant photodissociation channel and produces 2-buten-2-yl radicals with a range of internal energies that span the barriers to dissociation of the radical. Detection of the stable 2-buten-2-yl radicals allowed us to determine the translational, and therefore internal, energy that marks the onset of dissociation of the radical. Dissociation of the 2-buten-2-yl radical produces CH3 + propyne and imparts little translational energy to the products. Analysis of TOF spectra taken at m/e = 54 is in progress and may reveal contributions from 1,2-butadiene, 2-butyne, cofragments to HCl elimination and daughter fragmentation of 2-buten-2-yl. This poster presents these experimental results as well as a comparison to our previous theoretical predictions.

89

B1-06

Threshold is More Exciting: Seeing Reactive Resonance in a Polyatomic Reaction

Vincent W.C. Shiu1, Jim J. Lin1 & Kopin Liu1 Malcom Wu2 & David H. Parker2

1Institute of Atomic and Molecular Sciences, Academia Sinica P.O. Box 23-166, Taipei, Taiwan 106 2Department of Molecular and Laser Physics, University of Nijmegen Toernooiveld 1, 6525 ED Nijmegen, The Netherlands

A time-sliced ion imaging technique is applied to measure the reaction excitation function of F + CH4 → HF(ν′) + CH3(ν = 0) for the first time [1]. It was found the ″raw″ excitation function was significantly distorted by the density-to-flux transformation of the reaction. Near the reaction threshold, several remarkable observations were uncovered. In addition to the drastic change of co-product HF(ν′=2) rotational distributions ⎯ changing from a predominantly backward scattered low-j′ distribution at a higher collision energy to a distinct bimodal distribution with the high-j′ states preferentially scattered in the forward direction near reaction threshold, the formation of high-frequency, symmetric-stretch excited

CH3(ν = 1) products was detected. And its yield was found to be significant only near the threshold region. To interpret these findings, we surmise the existence of a reactive resonance in this polyatomic reaction [2]. The discovery of reactive resonance in a polyatomic reaction is more than just an extension from a typical atom + diatom reaction. As shown here, it holds great promise to disentangle the elusive intramolecular vibrational dynamics of transient collision complex in the critical transition-state region.

[1] Weicheng Shiu, Jim J. Lin, Kopin Liu, Malcom Wu, and David H. Parker, J. Chem. Phys. 120, 117(2004). [2] Weicheng Shiu, Jim J. Lin, and Kopin Liu, Phys. Rev. Lett. 92, 103201(2004).

90

B1-07

Dissociation of the Methanethiol Radical Cation Induced by Collisions with Ar Atoms: An Investigation by Quasiclassical Trajectories

Emilio Martínez-Núñez1, Jorge M. C. Marques2 and Saulo A. Vázquez1

1Departamento de Qímica Física, Universidade de Santiago de Compostela, Santiago de

Compostela, 15782, Spain

2Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal

Quasiclassical trajectory calculations were carried out to study the dynamics of energy

+ transfer and collision-induced dissociation (CID) of CH3SH + Ar at collision energies ranging from 4.34 to 34.7 eV. The relative abundances calculated for the most relevant product ions are found to be in good agreement with experiment, except for the lowest

+ energies investigated. In general, the dissociation to form CH3 + SH is the dominant channel, even though it is not among the energetically favored reaction pathways. The results corroborate that this selective dissociation observed upon collisional activation arises from a more efficient translational to vibrational energy transfer for the low-frequency C−S stretching mode than for the high-frequency C−H stretching modes, together with weak couplings between the low- and high-frequency modes of vibration. The calculations suggest

+ that CID takes place preferentially by a direct CH3 + SH detachment, and more efficiently

+ when the Ar-atom collides with the methyl group-side of CH3SH .

91

B1-08

The Photodissociation Dynamics of t-Butylnitrite Initiated by Excitation

to the S2 Electronic State

Thorsten Obernhuber, Uwe Kensy, and Bernhard Dick# Department of Physical Chemistry, University of Regensburg, 93040 Regensburg, Germany

Following excitation to the second excited singlet state S2, t-butylnitrite (TBN) dissociates with high quantum yield into the fragment radicals NO and t-butoxy.

N O N O O O

We have studied the population of rotational and vibrational states of the NO fragment by REMPI spectroscopy. For a variety of these final states the velocity distribution of the NO fragment was determined by the velocity-map ion-imaging method.

The rotational product state distribution is bimodal: One fraction (A) shows small rotational quantum numbers (J < 10), a second fraction (B) has high rotational quantum numbers in the range 50 – 70. The velocity distribution was in all cases well fitted by an expression of the form:

N ⎛ (v − v )2 ⎞ p(v,ϑ) = A v 2 exp⎜− j0 ⎟ × ()1+ β P (cosϑ) (1) ∑ j ⎜ 2σ 2 ⎟ j 2 j ⎝ j ⎠

The ion images yield a thermal and isotropic velocity distribution for fraction A. We assign these species to the dissociation of molecules inside clusters of TBN. For the fast rotating fragments (B) two components (N = 2) with positive anisotropy are observed. The faster component (v0 = 2350 m/s, σ = 200 m/s, β = 1.1) is assigned to the dissociation of free TBN molecules. The anisotropy indicates that the transition dipole of the S0 → S2 transition has a small angle with the dissociation coordinate, and that the dissociation occurs on a time scale much shorter than the rotational period of TBN. The second component has a smaller mean velocity with a broader distribution and significantly less anisotropy. It is assigned to the dissociation of TBN molecules located at the surface of clusters.

#) e-mail: [email protected]

92

B1-09

Photolysis of 2-Fluorotoluene at 193 nm: Internal Energy of HF Determined with Time-resolved Fourier-transform Infrared Emission Spectroscopy

Sheng-Kai Yang1, Hui-Fen Chen1, Suet-Yi Liu1, Chia-Yan Wu1, and Yuan-Pern Lee1, 2 1Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013 2Institute of Atomic and Molecular Sciences, Academia Sinica,Taipei, Taiwan 106

2-Fluorotoluene only differs from fluorobenzene by a methyl group, but its photochemistry is expected to be distinct from that of fluorobenzene. The HF-elimination channel may proceeds via either a four-center elimination from the ring structure or a five-center elimination involving the methyl group. Furthermore, 2-fluorotoluene might isomerize to a seven-member ring before dissociation takes place. Following photodissociation of 2-fluorotoluene at 193 nm, rotationally resolved emission spectra of

HF(v ≤ 3) in the spectral region 2700–4500 cm-1 are detected with a step-scan

Fourier-transform spectrometer. In the period 0–1μs after photolysis, rotational temperatures of HF are 1310 ± 80 K for v=1 and 1440 ± 260 K for v=2; a short extrapolation leads to a nascent rotational temperature of 1450 ± 200 K and a nascent energy of 12 ± 2 kJ mol-1.

Observed vibrational distribution of (v=1) : (v=2) : (v=3) = (64.5 ± 0.6) : (24.5 ± 0.1) : (11.1 ±

0.1) corresponds to a vibrational temperature of 6010 ± 340 K. An average vibrational energy of 27 ± 4 kJ mol-1 is derived based on observed population of HF(v ≥ 1) and an estimate of the population of HF(v = 0) by extrapolation. Possible dissociation mechanisms are discussed and our experimental results are compared with those of fluorobenzene at 193 nm.

93

B1-10

Inelastic State-to-state Scattering of Oriented OH by HCl

D.R. Cireasa1, A. Moise2 and J.J. ter Meulen2 1Physical and Theoretical Chemistry Laboratory, Oxford, United Kingdom 2 University of Nijmegen, Nijmegen, The Netherlands

The dynamics of a collision of two molecules depends crucially on the relative orientation of the colliding partners. Whereas a specific relative orientation may lead to a chemical reaction the same reaction may be prohibited when the molecules are oriented in the opposite direction. Thus far, collision studies are generally performed with non-oriented molecules and steric effects stay concealed. We have developed a technique based on electrostatic state selection in combination with a weak homogeneous electric field to select and orient OH molecules in the lowest rotational state. In previous crossed molecular beam studies of inelastic collisions of OH with Ar strong steric effects were revealed for inelastic collisions, showing differences for opposite orientations up to an order of magnitude [1,2]. We now report measurements of parity resolved inelastic scattering of OH (X2Π, J=3/2, f) by HCl. Relative state-to-state cross sections and their steric asymmetries were measured for rotational excitations up to J=9/2 in the Ω=3/2 spin-orbit ladder and up to J=7/2 in the Ω=1/2 spin-orbit ladder. A propensity for spin-orbit conserving transitions was found, but the generally observed propensity for excitation into particular Λ-doublet components was not evident. A comparison is made with results previously obtained for collisions of OH with

CO and N2. From this comparison it can be concluded that the potential energy surface (PES) governing the interaction between OH and HCl is more anisotropic than the PES’s governing the intermolecular interaction of OH with CO and N2. Whereas for scattering into low J states a preference for collisions at the O-side is found for OH-CO and OH-N2 the collisions at the H-side are preferred for the OH-HCl system. A possible explanation is the occurrence of reactions when the O-side is directed towards the HCl molecule, producing H2O and Cl. Experiments are now performed to measure the Cl atoms by (1+1) REMPI.

[1] M.C. van Beek, J.J. ter Meulen and M.H. Alexander, J.Chem.Phys. 113, 637 (2000) [2] M.C. van Beek, G. Berden, H.L. Bethlem and J.J. ter Meulen, Phys.Rev.Lett. 86, 4001 (2001)

94

B1-11

Quasiclassical Trajectory Studies of the Cl + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

J. F. Castillo1, F. J. Aoiz1, L. Bañares1 1Departamento de Química Física I, Universidad Complutense de Madrid,Madrid 28040, Spain

We present the results of Quasiclasical Trajectory (QCT) calculations for the reaction

Cl + CH4 → HCl + CH3 employing a global PES constructed by interpolation of ab initio Quantum Chemistry data using the method developed by Collins and co-workers [1]. Ab initio data (energy, gradients and hessian matrix) have been calculated at the QCISD/aug-cc-pVDZ level of theory.

Comparisons of HCl(v',j') rotational distributions and differential cross sections with experimental determinations [2,3] will be presented.

References:

1. M. A. Collins. Theor. Chem. Acc. (2002) 2. Z. H. Kim, A. J. Alexander, H. A. Bechtel, R. N. Zare, J. Chem. Phys. 115, 179, (2001). 3. J. Zhou, J. J. Lin, B. Zhang, K. Liu, J. Phys. Chem. "Richard Bershon Memorial Issue".

95

B1-12

Planetary Chemistry of C2H5 Radicals: Rate Constant for the CH3 + C2H5 Reaction at Low Temperatures and Pressures

André S. Pimentel1, Fred L. Nesbitt1,2, Walter A. Payne1, and Regina J. Cody1

1 Laboratory for Extraterrestrial Physics, NASA Goddard Space Flight Center Greenbelt, MD 2 Department of Chemistry, Catholic University of America, Washington, DC: also at Coppin State College, Baltimore, MD Many reactions of smaller hydrocarbon radicals which are important for combustion chemistry are also important in the photochemical modeling of the Outer Planets of the Solar System. However, the atmospheric conditions for the planetary atmospheres are different in terms of lower temperatures and pressures and smaller bath gases, i.e. He / H2. The ethyl radical, C2H5, is predicted by photochemical modeling to be one of the most abundant C2 species in the atmospheres of Jupiter and Saturn. The reaction CH3 + C2H5 is expected to be one of the important loss processes for C2H5 and an important source of C3H8 in these atmospheres. There have been four direct studies of the rate constant for the reaction CH3 +

C2H5 but none at the lower temperatures and pressures needed for the modeling studies of the atmospheres of the Outer Planets. Therefore, we are measuring the rate constant at T = 298 and 200 K, and P in the range of 0.4, 1 and 2 Torr. The measurements are performed in a discharge − fast flow system under pseudo-first order conditions with [C2H5]/[CH3]=10 − 110.

We monitor the decay of the CH3 radical via low-energy electron impact mass spectrometry. The results thus far show moderate dependence upon pressure and temperature. The rate −11 constants for the reaction CH3 + C2H5 are k(295K, 0.4 Torr) = (0.95±0.09)×10 , k(295K, 1 Torr) = (1.81±0.30)×10−11, k(295K, 2 Torr) = (3.02±0.63)×10−11, k(202K, 0.4 Torr) = (0.97±0.18)×10−11, k(202K, 1 Torr) = (2.64±0.59)×10−11, and k(202K, 2 Torr) = (3.27±0.75)×10−11, all in units of cm3 molecules−1 s−1. A comparison will be made with previous measurements.

Acknowledgements. The NASA Planetary Atmospheres Research Program supported this work. ASP thanks the National Academy of Science for the award of a research associateship.

96

B1-13

Experimental Studies of the Rate Coefficients 3 of the Reaction O( P) + CH3OH at High Temperatures

Sheng-Lung Chou1, Yuan-Pern Lee1, 2, and Ming-Chang Lin3 1Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 3Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA

Methanol is regarded as a promising alternative fuel. Exhausts from the engines powered by methanol is potentially much less polluting than gasoline, but incomplete combustion 3 produces toxic gas formaldehyde. The reaction O( P) + CH3OH is an important step to initiate oxidation processes of methanol. The rate coefficient has not been determined for temperatures above 1000 K. 3 Rate coefficients of the reaction O( P) + CH3OH in the temperature range 740-1400 K are determined using a diaphragmless shock tube. O(3P) atoms are generated by photolysis of

SO2 with an ArF(193 nm) or a KrF(248 nm) excimer laser; its concentration is monitored with atomic resonance absorption spectroscopy (ARAS) [1]. We model observed temporal profiles of [O] with 36 reactions using a commercial kinetic modeling program FACSIMILE. Rate coefficient of the title reaction is varied to yield the best fit for temporal profiles of [O]. Observed rate coefficients show Arrhenius behavior, with k(T) = (1.12±0.11)×10-10exp[-(3520±120)/T] cm3 moleucle-1 s-1. From the modeling, the dominant 3 secondary reaction below 1400 K is CH2OH+O( P)→CH2O+OH and the major secondary 3 reaction above 1400 K is CH3+O( P)→CH2O+H. Our results indicate that the preexponential factor and activation energy are greater than those reported by Just et al. [2] and Keil et al. [3]

[1] C.-W. Lu, Y-J. Wu, Y-P. Lee, R. S. Zhu, and M. C. Lin, J. Phys. Chem. A, 107, 11020 (2003). [2] H. H. Grotheer and T. Just, Chem. Phys. Lett., 78, 71(1981). [3] D. G. Keil, T. Tanzawa, E. G. Skolnik, R. B. Klemm, and J. V. Michael, J. Chem. Phys., 75, 2693 (1981).

97

B1-14

Electron Donor-Acceptor Bonds in the Methyl Radical Complexes

H3C-BH3, H3C-AlH3 and H3C-BF3: an ab initio Study

Ru-Jiao Li, Zhi-Ru Li1, Di Wu, Xi-Yun Hao, Bing-Qiang Wang,

Chia-Chung Sun

State Key Laboratory of Theoretical and Computational Chemistry, Institute of theoretical chemistry Jilin University, Changchun, 130023 P.R. China

A new kind of donor-acceptor complexes between methyl radical H3C and moleculesYZ3 (YZ3 = borane BH3, alane AlH3 and boron trifluoride BF3) is predicted and intermolecular single electron donor-acceptor bonds in these methyl radical complexes are found. The single electron bond lengths of H3C-BH3, H3C-AlH3 and H3C-BF3 complexes are 2.181 Å, 2.594 Å and 2.823 Å, respectively. The intermolecular single electron donor-acceptor bond energies are calculated by the CCSD(T)/aug-cc-pVDZ method with counterpoise procedure. The interaction energies of the H3C-BH3, H3C-AlH3 and H3C-BF3 complexes are -6.3 kcal/mol, -6.8 kcal/mol and -1.8 kcal/mol, respectively.

98

B1-15

Rapid Intersystem Crossing in Highly Phosphorescent Iridium Complexes

Kuan Lin Liu, Chao Han Cheng, Kuo-Chun Tang, and I-Chia Chen Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013

Six-coordinate tris-(phenylpyridine) iridium exhibits high phosphorescence efficiency, quantum yield up to 45 % at room temperature. High phosphorescence quantum yield is because of strong spin-orbit coupling. These types of complexes often show intense absorption from C^N (π – π)* in the blue to UV region and MLCT (metal to ligand charge transfer) transitions in the visible. Both 1MLCT and 3MLCT bands are typically observed and strong spin-orbit coupling is evident in comparing the oscillator strengths for the two MLCT bands. We use femtosecond optical gate technique to detect the emission rise curves of the 3MLCT state. The goal of this study is to explore this ultrafast dynamics of energy transfer in the iridium complex. Experimental results show that the formation of the triplet state is rapid ∼70 fs, and shorter than the system response (FWHM of cross correlation curve = 230 fs). There are two decay components observed; the short one (440 fs at λem = 490 nm and 1.1 ps at 580 nm) is assigned to be vibration cooling due to the solvent bath and the long one is the lifetime of the 3MLCT (47 ns in aerated BuCN solution). Close to the emission region of the 1MLCT, the fluorescence intensity is weak and is overlapped with that of 1MLCT. These experimental results show efficient intersystem crossing and explain the high emission quantum yield in these complexes. These results should also provide a fundamental understanding of the application of similar phosphorescent organometallic molecules in both photocatalysis and photovoltaic assemblies.

99

B1-16

Ultrafast Electron Transfer and Energy Transfer Dynamics of Porphyrin-TiO2 Nanostructures

Liyang Luo, Chia-Chen Chiang, and Eric Wei-Guang Diau* Department of Applied Chemistry and Center for Interdisciplinary Molecular Science, National Chiao Tung University, Hsinchu 30050, Taiwan, ROC Ching-Yao Lin* Department of Applied Chemistry, National Chi Nan University, Nantou 545, Taiwan, ROC

Photophysical properties of the ZnⅡ porphyrin (ZnP) and its derivatives the molecular structures are show below in solution and thin film have been investigated by time-resolved fluorescence spectroscopic methods. With excitation to the S2 state (B band) of ZnP in benzene at 400nm, the fluorescence transients show three consecutive components with time constants of ~2 ps for S2→S1 internal conversion, ~11 ps for solvent-induced vibrational relaxation and ~2 ns for S1→T1 intersystem crossing (ISC). The rapid energy transfer process due to aggregation was found to compete with the ISC process for the ZnBEDPP molecule coated on the glass. When ZnBEDPP coated on the TiO2 nanocrystalline thin film, the aggregation is ineffective and the ultrarapid interfacial electron transfer becomes dominant so that the emission due to ISC is scarely observed. Although the distance between the zinc cation and the TiO2 nanopaticle in ZnBEDPP is longer than that in ZnCATPP, the electron transfer rate of ZnBEDPP is faster than that of ZnCATPP, probably due to the better π -conjugation efficiency for the former than the latter.

100

B1-17

The Internal Energy Distribution and Alignment Properties of the

CH3O (X) Fragment by the Photodissociation of CH3ONO at 355 nm

Hong-Ming Yin, Ju-Long Sun, Shu-Lin Cong, Ke-Li Han*, and Guo-Zhong He

State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics,

Chinese Academy of Science, Dalian 116023, China

The photodissociation dynamics of methyl nitrite (CH3ONO) was studied using 355 nm

2 laser photolysis, and CH3O photofragments (X E v″ = 0, 1) were probed by single photon laser-induced fluorescence spectra. The ground vibrational state of the CH3O was found to be most populated, and the rotational distributions of each vibrational level were quite hot. The

(2) alignment parameter A0 between the electronic transition dipole moment µ involved in the absorption of the parent molecule and the rotational angular momentum J of the photofragment CH3O (v″ = 1) was measured. Polarization experiments showed that the rotational angular momentum of CH3O was aligned parallel to the transition moment of the

(2) parent molecule. The positive A0 values showed that the photodissociation process of

CH3ONO favored an in-plane momentum kick.

101

B2-01

Fourier-transform Microwave Spectroscopy and FTMW-millimeter-wave Double Resonance Spectroscopy of XOO (X = Cl, Br) Radicals

Kohsuke Suma,Yoshihiro Sumiyoshi, and Yasuki Endo Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan

ClOO is an important species for atmospheric chemistry because of its role in ozone destruction in the polar stratosphere. Many attempts to observe this radical by high-resolution spectroscopy in the gas phase have been unsuccessful so far, presumably because of its elusive nature due to the anomalously weak Cl–O bond which is almost equal to the hydrogen bond. In the present study, Fourier transform microwave (FTMW) spectroscopy with a pulsed discharge nozzle has been successfully applied to observe high-resolution spectra of ClOO in the gas phase for the first time. More than 200 a-type transitions (9GHz-39GHz) and 10 b-type transitions (80GHz) for the 35Cl and 37Cl isotopomers have been observed using FTMW and FTMW-millimeter-wave (MMW) double resonance spectroscopy, where the latter method enable us to observe b-type transitions. The rotational, centrifugal, spin rotation coupling, and hyperfine coupling constants have been determined by least squares fits. The hyperfine coupling constants indicate the species to have the 2A" ground electronic state, similar to related radicals, XOO, XSO and XSS (X=H, F,

Cl). The r0 structure is determined to be r0(OO) = 1.227Ǻ, and r0(ClO) = 2.075Ǻ, θ0(ClOO) = 116.4º. Extensive ab initio calculations have been performed, using SCF, B3LYP, CCSD(T), CASSCF and MRCI with aug-cc-pVXZ (X=D, T, Q, 5). However, many of them turned out to be inappropriate for ClOO, because it is indispensable to take account of static and dynamic electron correlations simultaneously. Only MRCI with a large basis set well reproduces the present experimental results. The re structure has been determined using the force field obtained by the ab initio calculations: re(ClO) = 2.0842(2) Ǻ, and re(ClO) = 1.2069(1)Ǻ, θe(ClOO) = 115.37(3)º. Microwave spectra of BrOO have also been observed. A detailed analysis similar to ClOO is now in progress. The nature of the anomalous XO bond for XOO becomes clear by the present experiments and ab initio calculations.

102

B2-02

Detection of Infrared Absorption of Gaseous ClCS Using Time-resolved Fourier-transform Spectroscopy

Huei-Lin Han1, Li-Kang Chu1, and Yuan-Pern Lee1, 2 1Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106

ClCS was produced upon photolysis of a flowing mixture of Cl2CS (0.72 Torr) and N2

(41.9 Torr) at 248 nm. N2 serves as a quencher to stabilize the internally excited ClCS. A step-scan time-resolved Fourier-transform infrared spectrometer coupled with a small multipass absorption cell (base path length 20 cm, effective path length 6.4 m and volume

3 1600 cm ) was employed to observe infrared absorption of photolysis products of Cl2CS.

With spectral resolution of 0.5 cm-1, a transient band consisting of P- and R-branches with an overlapped Q-branch was recorded. We estimate the band origin to lie at 1194.4 cm-1,

-1 consistent with a previous report of a line at 1189.3 cm attributed to the C−S stretching (ν1) mode of 35ClCS in solid Ar [1]. The geometry, rotational parameters, harmonic frequencies, and IR intensities are predicted with the UB3LYP/aug-cc-pVTZ density functional theory.

Predicted vibrational wave numbers of 1212.6 cm-1 (IR intensity of 289.3 km mole-1) for the

35 ν1 mode is consistent with our experiment. A simulated C−S stretching band of ClCS based on these calculated parameters is consistent with our experimental observation.

[1] G. Schallmoser, B. E. Wurfel, A. Thoma, N. Caspary, and V. E. Bondybey, Chem. Phys. Lett. 201, 528 (1993).

103

B2-03

On the Renner-Teller Effect and Barriers to Linearity and Dissociation in ~ HCF( A1A′′ )

Haiyan Fan,1 Ionela Ionescu,1 Chris Annesley,1 Ju Xin,2 and Scott A. Reid1 1Department of Chemistry, Marquette University, Milwaukee, WI 53201 2Department of Physics and Engineering Technologies, Bloomsburg University, Bloomsburg, PA 17815

To investigate the Renner-Teller effect and barriers to linearity and dissociation in the simplest singlet carbene, HCF, we recorded fluorescence excitation spectra of the pure bending levels (0,υ2′,0) with υ2′ = 0-7 and the combination states (1,υ2′,0) with υ2′ = 1-6 and ~1 ~1 (0,υ2′,1) with υ2′ = 0-3 in the HCF A A′′ ←X A′ system. The spectra were measured under jet–cooled conditions using a 140 pulsed discharge source, and rotationally 120 analyzed to yield precise values for the -1 band origins and rotational constants. 100

The approach to linearity in the à state is 80 evidenced in a sharp increase in the A 60 rotational constant (Fig. 1), a minimum in the bending vibrational intervals, and 40 rotational constant in cm constant rotational significant fluorescence lifetime A 20 lengthening in sub-bands with Ka′>0 due 0 to the Renner-Teller interaction. A fit 02468 of the vibrational intervals for the pure υ2' Fig. 1. Dependence of the A rotational constant bending levels yields a barrier to ~ in HCF( A1A′′ ) on quanta of bending excitation. linearity of 6300 ± 270 cm-1 above the Legend: ■ = (0,υ2′,0), ◊ = (1,υ2′,0), ○ = (0,υ2′,1). vibrationless level. Our observation of the Ka′ = 1 level of (1,6,0) places a lower limit on the à state barrier to dissociation of 8555 cm-1 above the vibrationless level. Where they can be compared, the derived à state parameters are in excellent agreement with the predictions of ab initio electronic structure theory.

104

B2-04

Detection of Predissociated Levels of the SO B 3Σ- State using Degenerate Four-wave Mixing Spectroscopy

Reginald Colin1, Ching-Ping Liu2 and Yuan-Pern Lee2, 3 1Laboratoire de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Belgium 2Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013 3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106

We demonstrate an application of the degenerate four-wave mixing (DFWM) technique to

3 - detect predissociated levels of the B Σ state of SO. Following photodissociation of SO2 in a supersonic jet with an ArF excimer at 193 nm, DFWM spectra of the B 3Σ-← X 3Σ- transition of SO in a spectral region 220-263 nm are recorded using a frequency-doubled dye laser.

Observed features show resolved rotational structures in regions well beyond those investigated with laser-induced fluorescence or emission techniques. The rotational analysis of several bands yields spectral parameters for the B 3Σ- state significantly improved over those reported previously. For example, based on the (8-1) and (8-2) bands, we obtained for

-1 the rotational constant Bv a value of 0.46009(4) cm and derived for the first time parameters

-6 -1 -1 for the centrifugal distortion Dv = 1.55(4)×10 cm , the spin-spin coupling λ = 2.78(1) cm

-4 -1 -3 -1 and λD = 6.9(3)×10 cm , and the spin-rotation coupling γ = -7.14×10 cm . Additional bands tentatively assigned as (2-2), (3-1), (3-2), (3-3), (4-2), (5-2), (6-2), (7-1), (7-2), and (9-2) are observed. Predissociation mechanisms of the B 3Σ- state are discussed.

105

B2-05

Electronic Structure from High Resolution Spectroscopy

N. L. Elliott1, J.A.J. Fitzpatrick1, O.V. Chekhlov1, S.H. Ashworth2 and C. M .Western1 1School of Chemistry, University of Bristol, Cantock's Close, Bristol UK 2School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, UK

We have developed [1] an all solid state, narrow bandwidth and continuously tuneable optical parametric oscillator (OPO) based on two β-barium borate non-linear crystals. The OPO is seeded using tuneable diode lasers and generates high power transform limited nanosecond light pulses directly in the ranges 770 – 1050 nm and 535 – 675 nm. Various frequency doubling and mixing schemes allow the range from 210-1050 nm to be covered. The bandwidth is ~ 130 MHz (0.004 cm–1) in the visible which translates to a resolution for UV spectra of 0.01 cm–1. We have applied this to a variety of free radicals, including PF[1], PH[2], NCO and CFBr. A selection of results in presented in this poster; for the first three species the resolution is sufficient to resolve the hyperfine structure and this is interpreted in terms of the bonding in the molecules. Such interpretation requires atomic reference values for comparison and it became clear from our work that the values normally used in the literature had some problems. We therefore undertook a series of ab initio calculations of the hyperfine constants of first and second row diatomics which provide revised atomic reference values giving more realistic descriptions of the bonding. For CFBr the resolution is sufficient to fully resolve the rotational structure for the first time; conventional dye laser spectra only show a band contour. We are therefore able to determine rotational constants for both the upper and lower state.

[1] J.A.J. Fitzpatrick, O.V. Chekhlov, J.M.F. Elks, C.M. Western and S.H. Ashworth. J. Chem. Phys. 115, 6920 (2001) [2] J.A.J. Fitzpatrick, O.V. Chekhlov, C.M. Western and S.H. Ashworth. J. Chem. Phys. 118, 4539 (2003).

106

B2-06

Cavity Ring-Down Spectroscopy of Polyatomic Transient Intermediates: H2CN and H2CNH

† Paul J. Dagdigian, Boris Nizamov, and Alexey Teslja Department of Chemistry The Johns Hopkins University Baltimore, MD 21218-2685 USA

Cavity ring-down spectroscopy (CRDS) has been employed to observe the electronic spectrum of the polyatomic transient intermediates methylene amidogen (H2CN) and methyleneimine (H2CNH). The H2CN radical was prepared by 193 nm photolysis of formaldoxime (H2CNOH). CRDS signals from both the H2CN and OH [A – X (1,0) band] fragments were observed in the 278 – 288 nm wavelength region. By comparing the H2CN and OH signal strengths and taking into account the reaction of OH with the precursor, the oscillator strength of the H2CN transition could be determined. A study of the room-temperature H2CN reaction kinetics was also carried out. Three H2CN excited electronic states are expected in the energy range probed. It was not possible to make electronic state assignments based on the rotational contours of the observed features in the room-temperature absorption spectrum of H2CN. Progress on the observation of the jet-cooled absorption spectrum will be reported at the meeting. Methyleneimine was prepared by the pyrolysis of methyl azide. CRDS signals were recorded over the 234 – 260 nm wavelength region as a function of the temperature of a heated section of tubing upstream of the CRDS cell. The absorption spectrum of H2CNH was found to be broad and structureless, with an absorption maximum near 250 nm.

Wavelength-dependent absorption cross sections of H2CNH were estimated by comparison with the known absorption cross sections of methyl azide. The 118 nm 1-photon photoionization and the UV multiphoton ionization mass spectra of a molecular beam of pyrolyzed methyl azide were also investigated. These results and previous quantum chemical calculations suggest that the S1 state decays by internal conversion, with subsequent loss of H or H2. The photophysics of methyleneimine is compared with that of the isoelectronic ethylene molecule.

† Present address: Department of Chemistry, University of California, Berkeley, CA 94720.

107

B2-07

Significant OH Radical Reactions in the Atmosphere: A New View

Ilana B. Pollack, Ian M. Konen, Eunice X. J. Li, and Marsha I. Lester Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323 USA

The three-body OH + NO2 + M → HONO2 + M association reaction is of fundamental importance in atmospheric chemistry because it is an important sink of reactive HOx and NOx radicals that directly affect the ozone budgets of the troposphere and stratosphere. Until very recently, HONO2 was believed to be the only product of the OH + NO2 reaction. However, a surprisingly large discrepancy between OH kinetic loss measurements performed at high and low pressures has lead several groups to suggest that peroxynitrous acid (HOONO), a less stable isomer of HONO2, may be a secondary product of this reaction and the coupled HO2 + NO reaction. Recently, this laboratory produced HOONO by reaction of photolytically generated

OH and NO2 radicals, stabilized the intermediate in a pulsed supersonic expansion, and identified the trans-perp (tp) conformer of HOONO through infrared action spectroscopy in the OH overtone region.[1] Extensive rotational band structure associated with the OH overtone transition yields structural parameters and its transition dipole moment, which are in good accord with ab initio values. The infrared overtone excitation provides sufficient energy to break the O-O bond of tp-HOONO, producing OH (v=0) fragments that are detected. The internal energy distribution of the OH fragments is consistent with a prior distribution, and enables an accurate determination of the HOONO binding energy. The spectroscopically derived value is in good accord with recent theoretical results and a kinetic estimate of its stability. Comparisons will be made with previous infrared studies of HOONO conformers isolated in Ar matrices [2] and more recent studies in a discharge flow tube.[3,4] Many issues concerning the formation, isomerization, dissociation, and yield of HOONO under jet-cooled and atmospheric conditions will be discussed in the oral and poster presentations.

[1] I. B. Pollack, I. M. Konen, E. X. J. Li, and M. I. Lester, J. Chem. Phys. 119, 9981 (2003). [2] B. M. Cheng, J. W. Lee, and Y. P. Lee, J. Phys. Chem. 95, 2814 (1991); W.-J. Lo and Y. P. Lee, J. Chem. Phys. 101, 5494 (1994). [3] S. A. Nizkorodov and P. O. Wennberg, J. Phys. Chem. A 106, 855 (2002). [4] B. D. Bean, A. K. Mollner, S. Nizkorodov, G. Nair, M. Okumura, S. P. Sander, K. A. Peterson, and J. S. Francisco, J. Phys. Chem. A 107, 6974 (2003).

108

B2-08

1 First Observation of the ( A1) State of SiH2 and SiD2 Radicals by the OODR Spectroscopy

Yasuhiko Muramoto, Haruki Ishikawa1, and Naohiko Mikami Department of Chemistry, Graduate School of Science, Tohoku University 1E-mail: [email protected]

Silylene (SiH2) is a silicon analogue of methylene (CH2). The number of spectroscopic ~ 1 ~ studies on SiH2 is much smaller compared with that on CH2. Until now, only the X A 1, ~ 1 ~ 1 A B1, and a B1 states have been experimentally investigated. Recently, energetics and ~ 1 equilibrium structure of the next low-lying B A1 state were studied by high-level calculations by Yamaguchi et al.[1] However, a corresponding electronic state has not yet been observed.

In the course of our SEP spectroscopic study on highly excited vibrational levels of SiH2 [2], ~ we have identified several bands that can be assigned as transitions to the B state for the first ~ time. In this paper, we will report results of our first observation of the B state of SiH2 and

SiD2. ~ When a J = 0 rotational level of the A state was used as an intermediate level of the OODR measurement, several vibronic bands of 1100 – 1200 cm-1 interval were observed in ~ the energy region of 28000 – 30100 cm-1 above the X state. Based on a rotational selection rule and a predicted bending vibrational frequency, we assigned these bands as an odd-v2 ~ progression. This means that the SiH2 in the B state behaves as a linear molecule. To confirm our assignment, it is necessary to observe OODR spectra via a Ka = 1 rotational level. To avoid a difficulty in measuring desired OODR transitions due to a predissociation in ~ the A state of SiH2, an OODR spectroscopy of SiD2 was carried out. We have succeeded in ~ measuring the OODR transitions to the B state of SiD2 and have determined the value of T0 of -1 SiD2 to be 27214.11 cm . Our observation on SiD2 confirmed the quasi-linear behavior in ~ the B state. Details of our observation will be presented in the paper.

[1] Y. Yamaguchi, T. J. Van Huis, C. D. Sherrill, H. F. Schaefer III, Theor. Chem. Acc. 97, 341 (1997). [2] H. Ishikawa, Y. Muramoto, and N. Mikami, J. Mol. Spectrosc. 216, 90 (2002).

109

B2-09

Metal Hydrides in Astronomy

P. Bernath1, C.W. Bauschlicher2, M. Dulick3, R.S. Ram4, and A. Burrows5

1Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 2NASA Ames Research Center, Mailstop 230-3, Moffett Field, CA 94035 3 National Solar Observatory, 950 N. Cherry Ave., P.O. Box 26732, Tucson, AZ 85726-6732 4Department of Chemistry, University of Arizona, Tucson, AZ 85721 5Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721

Metal hydrides are prominent in the near infrared spectra of cool stars, particularly

M-type dwarfs, and in substellar objects such as brown dwarfs. Brown dwarfs are cool objects that have surface temperatures intermediate between those of stars and those of giant planets such as Jupiter. The L-type class of brown dwarfs is characterized by the presence of metal hydrides such as CrH and FeH, and the absence of metal oxides such as TiO and VO. We have recently started a project on the computation of molecular opacities of metal hydrides.

Our general approach is to combine new laboratory measurements with theoretical calculations. Work on CrH, FeH and TiH will be presented.

110

B2-10

Fourier Transform Spectroscopy of Gold Oxide, AuO

Leah C. O’Brien and Sarah Hardimon Southern Illinois University, Edwardsville, IL, USA

The near infrared spectrum of AuO has been recorded using the Fourier transform spectrometer associated with the National Solar Observatory at Kitt Peak, AZ. The gas phase AuO molecules were produced in a neon-based electric discharge using a gold-lined hollow cathode with a trace amount of oxygen. Two bands were observed in the spectrum,

-1 2 with red-degraded bandheads located at 10665 and 10726 cm , currently assigned as Π1/2 - X

2 2 2 Π1/2 and Π3/2 – X Π3/2 transitions, respectively. Results of the analysis will be presented.

This is the first reported spectral observation of gold oxide.

111

B2-11

The First Observation of the Rhodium Monofluoride Molecule Jet-cooled Laser Spectroscopic Studies

Walter J. Balfour,1 Runhua Li,1 Roy H. Jensen,1 Scott A. Shephard2 and Allan G. Adam2

1Department of Chemistry, University of Victoria, Victoria BC, V8W 3P6, Canada 2Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick, E3B 6E2, Canada

Rhodium monofluoride has been observed and spectroscopically characterized for the first time. RhF molecules were produced under jet-cooled conditions in a laser vaporization molecular beam source by the reaction of a laser-vaporized rhodium plasma with SF6 doped in helium, and studied with laser-induced fluorescence spectroscopy under both medium- and high-resolution. More than 25 LIF bands have been observed between 18500 and 24500 cm-1 and five of these have been recorded at 200 MHz resolution. All bands of appreciable intensity have been rotationally analyzed. The ground electronic level has Ω = 2, which is attributed to an inverted 3Π state from the 2δ46π312σ1 electron configuration. The ground level rotational constants are B = 0.27245 cm-1, D = 1.035×10-7 cm-1. Very small ground level Λ-doublings are evident in the spectrum. Excited states having Ω = 1, 2 and 3 have been identified. Dispersed fluorescence spectroscopy from eleven excited levels has been used to locate a large number of low-lying vibronic states within the energy range up to 8000 cm-1. A ground state vibrational interval of ~ 575 cm-1 is suggested. Preliminary results for

RhCl will also be given.

112

B2-12

Spectroscopy of Free Radicals in Hydrocarbon Oxidation

Terry A. Miller Laser Spectroscopy Facility, Department of Chemistry The Ohio State University, 100 W. 18th Avenue Columbus Ohio 43210

Over two-thirds of the industrialized world’s energy is still derived from the combustion (oxidation) of fossil fuels, which are of course mostly hydrocarbons. Vast quantities of organic molecules are injected from both biogenic and anthropengic sources into the troposphere, where they are degraded mostly by oxidative mechanisms. Free radicals play a key role in these processes; the simplest such oxygen-containing radicals form the alkoxy, RO, and peroxy, RO2, families, which we have spectroscopically investigated. Historically organic peroxy radicals have been monitored by their UV absorption, which is broad, unstructured, and ill-suited to distinguishing among peroxy species. The RO2 radicals have a ~ ~ weak A - X absorption that we have exploited as a species specific diagnostic using near IR cavity ringdown spectroscopy (CRDS). Our CRDS observations include alkyl peroxy radicals with R=CH3, C2H5, C3H7, and C4H9. For the latter two the CRDS spectra generally distinguish among the multiple isomers and conformers. We have also detected the spectra of substituted peroxy radicals with R=CF3 and CH3C(O). CF3O2 is involved in the atmospheric oxidation of chlorofluorocarbons, while CH3C(O)O2 reacts with NO2 to form a key atmospheric pollutant, PAN. Some time ago, we observed for the first time the laser induced fluorescence of a number of larger alkoxy radicals, CnH2n+1O (3 ≦ n ≦ 12) in a supersonic free jet expansion and recently extended these observations to cyclohexoxy. The larger alkoxy radicals with multiple structural isomers possible, exhibit more structural complexity than the smallest members of the family, methoxy and ethoxy. Initially it was believed that spectral bands above the origin ~ of each isomer corresponded to excited state vibrational structure in the observed B － ~ X electronic transitions, as was the case for CH3O and C2H5O. However rotational analyses of these bands showed this not to be true. The rotational structure “bar-codes” the transitions for each radical into distinct groups. Comparison of the common spectroscopic parameters (rotational and spin-rotation constants) for each group with quantum chemistry calculations assigns the groups to different conformers.

113

B2-13

Anomalous Splittings of Torsional Sublevels Induced by the Aldehyde Inversion Motion in the S1 State of Acetaldehyde

Yung-Ching Chou* and I-Chia Chen Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013, Republic of China *Present address of Chou: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106, Republic of China Jon T. Hougen Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8441

During the course of an analysis of the electronic absorption spectrum of acetaldehyde

(CH3CHO), highly anomalous and irregular torsional splittings were observed in the S1 state.

It turns out that a G6 group-theoretical high-barrier formalism developed previously for internally rotating and inverting CH3NHD can be used to understand these abnormal torsional splittings for the levels 140−150, 140−151, and 140−152, where 140− denotes the upper inversion tunneling component of the aldehyde hydrogen and 15 denotes the methyl torsional vibration. m This formalism, derived using an extended permutation-inversion group G6 , treats simultaneously methyl torsional tunneling, aldehyde-hydrogen inversion tunneling and overall rotation. Fits to the rotational states of the four pairs of inversion-torsion vibrational levels (140+150A,E, 140−150A,E), (140+151A,E, 140−151A,E), (140+152A,E, 140−152A,E), and (140+153A,E, 140−153A,E) are performed, giving rms deviations of 0.003, 0.004, 0.004 and 0.004 cm-1, respectively, which are nearly equal to the experimental uncertainty of 0.003 cm-1. Even for torsional levels lying near the top of the torsional barrier, this theoretical model, after including higher-order terms, provides a satisfactory explanation for the experimental data. A smaller anomaly, observed in the K-doublet structure of the S1 state, which deviates from that in a simple torsion-rotation molecule, can also be understood using this formalism and is shown to arise from coupling of torsion and rotation motion with the aldehyde hydrogen inversion. Possible application to proton transfer: From the viewpoint of molecular symmetry, the motion of intramolecular proton transfer is similar to that of CHO inversion (wagging) in the S1 state of acetaldehyde. Hence, the group-theoretical high-barrier formalism (G12) should also be able to describe the interaction between proton transfer and CH3 torsion in the ground vibrational level of methylmalonaldehyde (α-methyl-β-hydroxyacrolein) and 5-methyltropolone. This possibility is under exploration at the present time.

114

B2-14

Absorption Spectra of O2 and NO in 105-200 nm Wavelength Region Measured by using a Supersonic Jet

P. C. Lee, J. C. Yang, and J. B. Nee

Department of Physics, National Central University, Taiwan 32054

The photoabsorption spectrum of O2 in 105~130 nm is very complicated due to overlapping and complex structures. We have recently investigated O2 by using a supersonic jet beam and with light source of the synchrotron radiation from the High-Flux beamline at NSRRC. The spectrum is simplified compared with room temperature results. For example, in the wavelength region 111.8~112.7 nm the room temperature spectrum is conjested and 3 complex consisting of the triplet structure of a few transitions including transitions F Πu− 3 - 3 + 3 - X Σg and D’ Σu − X Σg among others as shown in Fig.1 In the jet spectrum the 3 + 3 - forbidden (1,0) band of the D’ Σu − X Σg could be identified. The perturbed transition 3 3 - (0,0) band of E’ Σu- − X Σg was also simplified. This allows the assignment of bands in 107.1~116.8 nm to be made easier. Results in other wavelength regions will be also shown.

2 The ground state of NO has a symmetry X ΠΩ with a fine structure separation of about 121 cm-1 between the levels Ω ”=3/2 and 1/2. Supersonic jet is useful to cool NO so that only the Ω=1/2-1/2 sub-bands dominates the spectral features. In the wavelength region 184-192 nm, there are several excited states of NO including mixing of the states D2Σ(v’=0) with A2Σ(v’=4). But in the supersonic experiment, results are simplified. The bands of the B2Π(v’=9) and C2Π(v’=0) are also simpler compared with the room temperature spectrum as shown in Fig. 1.

We think the experimental conditions can be improved in the future to simplified the spectrum further. Fig. 1 The supersonic jet spectrum of O2 and NO in 118 nm and 182 nm region.

Pulse-jet absorption

absorption by computer simulation 7 3 Room temperature absorption 7 C(v'=1) 6 2 6

5 1 5 C(v'=0) 4 0 4 F 3Π (3,0) u

(Mb) D(v'=0)/A(v'=4)

abs 3 - 3

σ E' Σ (0,0) 3 u -1

3 + D' Σ (1,0) 2 2 u -2 Absorbance (a.u.) Absorbance B(v'=9) 1 1 -3

0 0 -4 181 182 183 184 185 186 187 188 189 190 191 192 111.8 111.9 112.0 112.1 112.2 112.3 112.4 112.5 112.6 112.7 Wavelength (nm) Wavelength (nm)

115

B2-15

Rovibronic Energy Level Structure of the Two Lowest Electronic States of the Ozone Cation

Stefan Willitsch1, Fabrizio Innocenti2, John M. Dyke2 and Frédéric Merkt1

1 Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland 2 Department of Chemistry, The University, Southampton SO17 1BJ, United Kingdom

The rovibronic energy level structure of the two lowest electronic states of the ozone + cation O3 has been studied by pulsed-field-ionisation zero-kinetic-energy (PFI-ZEKE) photoelectron spectroscopy at a resolution of 0.4 cm-1 following single-photon excitation 2 from the neutral ground state. For the first time, the ordering of the nearly degenerate A1 and 2 B2 electronic states could be unambiguously established experimentally by an analysis of their rotational structure using symmetry selection rules and a quantitative model for rovibronic photoionisation cross sections of asymmetric tops [1]. The adiabatic ionisation

~ +2 ~ +2 -1 energies of the X A1 and A B2 states were determined to be 101020.5±0.5 cm (12.52494±

-1 ~ +2 0.00006 eV) and 102110.1±0.6 cm (12.66004±0.00007 eV), respectively. In the X A1 state,

+ a pronounced progression in the bending mode up to ν2 = 3 is observed. The vibronic

-1 ~ + 2 structure at excitation energies≧1500 cm with respect to the origin of the X A1 state

~ + 2 ~ + 2 appears to be severely perturbed as a result of vibronic mixing between the X A1 and A B2 states in the vicinity of a conical intersection [2]. The analysis of the photoionisation dynamics reveals that the photoelectron is ejected as a superposition of even and odd partial waves for transitions to both states, in line with the mixed angular momentum character of the molecular orbitals from which the photoelectron is removed.

[1] S. Willitsch, U. Hollenstein, and F. Merkt, J. Chem. Phys. 120, 1761 (2004) [2] H. Müller, H. Köppel, and L.S. Cederbaum, J. Chem. Phys. 101, 10263 (1994)

116

B2-16

Isomers of OCS2: IR Absorption Spectra of OSCS in Solid Argon

Wen-Jui Lo1, Hui-Fen Chen2, Po-Han Chou2, and Yuan-Pern Lee2, 3 1Department of Nursing, Tzu Chi College of Technology 880, Sec. 2, Chien kuo Road, Hualien, Taiwan 970 2Department of Chemistry, National Tsing Hua University 101, Sec. 2, Kuang Fu Road, Hsinchu, Taiwan 30013 3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106

The reaction of O atom with CS2 is important in the atmosphere, especially for the sulfur 3 3 cycle. Three product channels have been reported: (1a) O( P) + CS2 → CS + SO, (1b) O( P) 3 + CS2 → OCS + S, and (1c) O( P) + CS2 → CO + S2. Reaction (1a) is the major channel; it proceeds via direct abstraction to form two unstable species. Small branching ratios of Reactions (1b) and (1c) indicate that barriers for these reactions might be large and the adduct

OCS2 plays an important role. Froese and Goddard [1] performed theoretical calculations on

Reaction (1) and located five stable isomers of OCS2. To our knowledge, no spectral information on any of the possible conformers of OCS2 has been reported.

Irradiation of an Ar matrix sample containing O3 and CS2 with a KrF excimer laser at 248 nm yields OSCS. New lines at 1402.1 (1404.7), 1056.2 (1052.7), and 622.3 cm-1 appear after photolysis; numbers in parentheses correspond to species in a minor matrix site.

Secondary photolysis at 308 nm diminishes these lines and produces CO and CS2. These lines are assigned to C=S stretching, O−S stretching, and S−C stretching modes of OSCS, respectively, based on results of 34S-isotopic experiments and theoretical calculations. Theoretical calculations using density-functional theories (B3LYP/aug-cc-pVTZ) predict four stable isomers of OCS2: O(CS2), SSCO, OSCS, and SOCS, listed in increasing order of energy. According to calculations, OSCS is planar, with bond lengths of 1.51 Å (O−S), 1.63 Å (S−C), and 1.55 Å (C=S), and angles ∠OCS ≅ 111.9∘and ∠SCS ≅ 177.3∘; it is less

-1 stable than SSCO and O(CS2) by ~102 and 154 kJ mol and more stable than SOCS by ~26 kJ mol-1. Calculated vibrational wave numbers, IR intensities, 34S-isotopic shifts for OSCS fit satisfactorily with our experimental results.

[1] R. D. J. Froese and J. D. Goddard, J. Chem. Phys. 98, 5566 (1993).

117

B2-17

Gas-Phase Reactions of Organic Radicals and Diradicals with Ions

Xu Zhang, Shuji Kato, Veronica M. Bierbaum, and G. Barney Ellison Department of Chemistry and Biochemistry, University of Colorado Boulder, CO 80309-0215, USA

Reactions of polyatomic organic radicals with gas phase ions have been studied. A supersonic pyrolysis nozzle produced a clean and intense stream of hydrocarbon radicals/diradicals which were studied with a flowing afterglow selected ion flow tube (FA-SIFT) instrument. Reactions of a simple radical, allyl (CH2CHCH2), and a diradical, + - ortho-benzyne (o-C6H4), with hydronium (H3O ) and hydroxide (HO ) ions were studied at thermal energy (roughly 300 K).

+ + CH2CHCH2 + H3O → C3H6 + H2O - CH2CHCH2 + HO → no product ions + + o-C6H4 + H3O → C6H5 + H2O - - o-C6H4 + HO → C6H3 + H2O

+ The proton transfer reactions with H3O occur rapidly at nearly every collision (kII ~ -9 3 -1 - 10 cm s ). An unexpected result has been obtained for o-C6H4 + HO ; the exothermic proton abstraction is significantly slower than the collision rate by nearly an order of magnitude (kII ~ 10-10 cm3 s-1). This has been rationalized by competing associative - detachment. No charged products have been observed for CH2CHCH2 + HO , presumably because of similar detachment pathways.

[1] X. Zhang, V. M. Bierbaum, G. B. Ellison, S. Kato, J. Chem. Phys. 120, 3531 (2004).

118

B2-18

+ H3 Dissociative Recombination and the Cosmic-ray Ionisation Rate towards ζ Persei

M. Larsson,1 B. J. McCall,2 A. J. Huneycutt,2 R. J. Saykally,2 T.R. Geballe,3 N. Djurić,4,* G. H. Dunn,4 J. Semaniak,5 O. Novotny,5 A. Al-Khalili,5 A. Ehlerding,1 F. Hellberg,1 S. Kalhouri,1 A. Neau,1 A. Paál,6 R. Thomas,1 and F. Österdahl6

1Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden 2Department of Chemistry, University of California, Berkeley, CA 94720, USA 3Gemini Observatory, 670 North Aóhoku Place, Hilo, Hawaii 96720, USA 4JILA, University of Colorado and NIST, Boulder, CO 80309, USA 5Swietokrzyska Akademy, 235 406 Kielce, Poland. 6Manne Siegbahn Laboratory (MSL), Stockholm University, S104 05 Stockholm, Sweden

+ The H3 molecular ion plays a fundamental The absolute cross section for dissociative + role in interstellar chemistry, as it initiates a recombination of rotationally cold H3 was network of chemical reactions that produce measured, and based on this measurement a many interstellar molecules. In dense clouds, the thermal rate coefficient was calculated. This + H3 abundance is understood using a simple result is shown in Figure 1. The result is in very + chemical model, from which observations of H3 good agreement with new theoretical result [3]. yield valuable estimates of cloud path length, density, and temperature. On the other hand, observations of diffuse clouds have suggested + ) -7 that H3 is considerably more abundant than -1

s 10 expected from chemical models. However, 3 (cm diffuse cloud models have been hampered by e k large uncertainties in the adopted values of three key parameters: the cosmic-ray ionisation rate, -8 + 10 the electron fraction, and the rate of H3 destruction by electrons. Here we report a direct 10 100 1000 + Electron temperature (K) experimental measurement of the H3 destruction rate under nearly interstellar Figure 1: Calculated thermal rate coefficient ke conditions [1]. Wee also report the observation for the dissociative recombination of rotationally + + of H3 in a diffuse cloud (towards ζ Persei) [1], cold H3 as a function of electron temperature, where the electron fraction is already known based on CRYRING measurements. from satellite measurements. Taken together, these results remove two of three uncertainties in We would like to thank the staff at MSL for the chemical models and suggest that the their help. This work was supported by the IHP cosmic-ray ionisation rate in diffuse clouds is Programme of the EC under contracts forty times faster than previously assumed. HPRN-CT-2000-00142 and The experiment was carried out in the ion HMPT-CT-2001-00226, by the Miller Institue storage ring CRYRING at the Manne Siegbahn for Basic Research in Science, and also in part + Laboratory (MSL). Rotationally cold H3 by the DOE under Contract No. populating only the (J=1, K=1) and (J=1, K=0) DE-A102-95ER54293. V. Koukoouline and C.H. levels was produced by means of a supersonic Greene are acknowledged for communicating expansion ion source. In this source, a direct data prior to publication and for valuable current discharges creates a plasma in hydrogen discussions. gas (at 2.5 atmospheres) supersonically expanding into a vacuum through a 500 µm References: pinhole nozzle [2]. The rotational temperature [1] B.J. McCall et al., Nature 422, 500 (2003). was 20−60 K, based on measurements by cavity [2] B.J. McCall et al., Phys. Rev. A (submitted) ringdown laser absorption spectroscopy. [3] V.Koukoouline and C.H. Greene, Phys.Rev.Lett. 90, 133201 (2003).

119

B2-19

The Reaction Mechanism of O(1D) with Ethylene: the Product Yield Measurements of OH, CH2CHO and H atom

T. Oguchi, T. Hattori and H. Matsui Toyohashi University of Technology, Toyohashi, Japan

1 The reaction of O( D) + C2H4 → products (1) has been investigated by laser-induced fluorescence method (LIF) at room temperature. O(1D) is produced by pulsed laser photolysis of N2O. OH and CH2CHO radicals are observed by using UV probe laser light, and H atom is detected by using VUV laser light generated by tripling technique in Kr and Ar mixture. OH 1 1 and H yields per generated O( D) are measured by comparing with O( D) + H2 → OH + H (φ 3 ~ 1) (2) reaction. CH2CHO yield is measured by comparing with O( P) + C2H4 → CH2CHO + 1 3 1 H (φ ~ 0.42 ) (3), where, O( P) is supplied by quenching O( D) in a N2 buffer. The branching fractions of OH, CH2CHO, and H formation channels are obtained as 0.10, 0.07, and 0.3, respectively. Figure 1 shows the estimated reaction energy diagram of the title reaction from 2,3 ab initio calculrations. Fairly small fractions of OH and CH2CHO channels indicate that the simple bond fission process after the O(1D) insertion into C-H bond is less than half of total mechanism and CH3 + CHO or CO + CH4 channel via chemically excited CH3CHO is supposed to be dominant. This result is consistent with the CH3 yield measurements of this reaction.4 References 1) Koda et al., J. Phys. Chem. 95, 1241 (1991). 2) Fueno et al. Chem. Phys. Lett., 167, 291 (1990). 3) Abou-Zied et al., J. Chem. Phys., 109, 1293 (1998). 4) Miyoshi et al., private communication.

O(1D)＋C H 500 2 4 （２A') CH CH O + H （2A"） 2 CH CH O + H 400 2 C H =C H 2OH＋H OH + C2H ３ CH =CHOH＋H -1 2 300

mol 3 O(P)＋C2H 4 CH3CO + H

200 CH + CO + H 2 3 k J （A'）

CH2CH2O CH3+C H O

/ 100

H,f0

Δ 0

-100 H O -H C=C CO + CH４ H Ｈ -200 CH3CHO 1 Fig. 1 Estimated reaction energy diagram of O( D)+C2H4 reaction.

120

B2-20

Dissociative Recombination of Astrophysically Important Isoelectronic Ions

W. D. Geppert1, R. Thomas1, A. Ehlerding1, F. Hellberg1, F. Österdahl2, T. J. Millar3, J. Semaniak4, M. af Ugglas5, N. Djuric6, M. Larsson1

1Department of Physics, Alba Nova, Stockholm University, SE-106 91 Stockholm, Sweden 2Department of Physics, Alba Nova, Royal Institute of Technology, SE-106 91 Stockholm, Sweden 3Department of Physics, UMIST, PO Box 88, Manchester M60 1QD, UK 4Institute of Physics, Świętokrzyska Academy, ul. Świętokrzyska 15, PL-25406, Kielce, Poland 5Manne Siegbahn Laboratory, Frescativägen 24, SE-104 05 Stockholm, Sweden 6JILA, University of Colorado 440 UCB Boulder, CO 80309-0440, USA

Branching ratios in the dissociative recombination reactions of the astrophysically relevant + + + + pairs of isoelectronic ions DCO and N2H as well as DOCO (as substitute for HOCO ) and + N2OD have been measured using the CRYRING storage ring at the Manne Siegbahn Laboratory at Stockholm University, Sweden. For DCO+, the channel leading to D and CO was by far the most important one (branching ratio 0.88), only small contributions of the CD + O and OD + C product pathways (branching ratios 0.06 each) were recorded. In the case of + N2H the surprising result of a break-up of the N-N bond to N and NH (with a branching ratio 0.64) was found. In contrast to the behaviour of these two ions, branching ratios of DOCO+ + and N2OD were more similar: In both cases, three-body break-ups and elimination of OD were the dominating pathways [1].

Dissociative recombination of HCO+ (DCO+) can lead to CO in the excited a3Π state, which is supposed to cause the so-called Cameron bands in the Red Rectangle [2]. By analysing the kinetic energy release employing the imaging method and assuming a statistical distribution into the product states, a branching of 40 ± 20 % into the mentioned state was obtained, which strengthens the validity of this assumption.

+ + + For the dissociative recombination of N2H , N2OD and DOCO also absolute reaction cross sections were obtained in the collisional energy range between 0 and 1 eV, from which it was possible to work out the thermal rates. In addition, we have tested the effect of the new branching ratios on the chemical evolution models of large astrophysical reaction networks. Calculations have been performed for a model dark cloud similar to TMC-1 assuming a 4 -3 temperature of 10 K and a (H2) density of 10 cm using a standard model [3]. Inclusion of the new values led to an improvement of the congruence between predicted and observed molecular abundance values in this cloud, especially for nitrogen-containing compounds.

[1] W.D. Geppert, R. Thomas, A. Ehlerding, Jacek Semaniak, Fabian Österdahl, Magnus af Ugglas, Nada Djuric, András Paál and Mats Larsson, Faraday Disc. 117 (2004), in press. [2] D. Strasser, J. Levin, H. B: Pedersen, O. Heber, A. Wolf, D. Schwalm, D. Zajfman, Phys. Rev. A 65, 010702 (2001). [3] M. Yan, A. Dalgarno, W. Klemperer, A.E.S. Miller, Mon. Not. R. Astron. Soc. 313, L17 (2000). [4] A. Markwick, T. J. Millar, S. B, Charnley, S. B., Astrophys. J., 535, 256 (2000).

121

B2-21

Photoelectron Spectroscopy of Nitric Oxide Doped in Helium Droplets

Darcy S. Peterka1,2, Jeong Hyun Kim2, Chia C. Wang1,2, Musahid Ahmed2 and Daniel M. Neumark1,2

1 Department of Chemistry, University of California, Berkeley, CA 94720, USA 2 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA

The study of molecular structures and interactions doped in helium droplets is a challenging topic today. Due to its superfluidity and the ability to host foreign species it provides a gentle, universal, homogeneous, nearly perfect cryogenic matrix for scientific studies. The unique environment provided by helium droplets has demonstrated its capability to be an excellent medium for spectroscopic purpose.

The electronically excited molecules and ionization dynamics in helium droplets remains an unexplored field. Our current research is centered on understanding ionization phenomena in pure and doped helium nanodroplets. We report here our investigation of multiphoton ionization of helium droplets doped with one or more NO molecules. The NO chromophore is ionized by resonant multiphoton absorption via the excited A state (~226 nm), and the resulting photoelectron and mass spectra are measured as a function of excitation wavelength. The purpose of this work is to compare the ion yield and photoelectron spectra of NO inside a droplet to the well-known results for bare NO.

122

C1-01

3 Dynamics of HCCO and CH2 Radical Formation from the Reaction O( P) + C2H2 in Crossed Beams using Soft Electron Impact Ionization for Product Detection

G. Capozza, F. Leonori, E. Segoloni, G. G. Volpi, and P. Casavecchia Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy

We have recently introduced, for the first time, the concept of "soft" electron-impact (EI) ionization by tunable electrons (7-100 eV) for product detection in crossed molecular beams (CMB) reactive scattering experiments with mass spectrometric detection [1]. Analogously to when using "soft" photo-ionization (PI) by tunable VUV synchrotron radiation [2], by tuning the electron energy below the threshold of the dissociative ionization of interfering species, one can often eliminate background signal that would normally prohibit experiments using classic, i.e., "hard" (with 60-200 eV electrons), EI ionization (the latter is plagued by the well known problem of the "dissociative ionization", which leads to extensive fragmentation). Soft EI ionization is crucial for disentangling the dynamics of complex polyatomic reactions. In addition, because absolute EI ionization cross sections can be reliably estimated, branching ratios can also be determined. 3 The first reaction to the investigation of we have applied this approach is O( P) + C2H2, of considerable importance in combustion chemistry. Two main pathways are energetically open at thermal energies:

3 0 O( P) + C2H2 → HCCO + H ∆H 0 = −19.5 kcal/mol (1a) 0 → CH2 + CO ∆H 0 = −47.1 kcal/mol (1b)

We have studied the reaction at two collision energies, Ec=9.5 kca/mol and Ec=13.1 kcal/mol (the latter was obtained by crossing the two same reactant beams at 135° rather than at 90°, which affords a higher angular and time-of-flight (TOF) resolution). This reaction was 18 18 previously studied in CMB at Ec= 6 kcal/mol [3] using O to be able to detect C O in TOF measurements. In our experiments, by using 17 eV electrons for product ionization we have been able to detect CH2 radicals from channel 1b with nearly no background and, most important, without contribution from interfering signals (arising from C2H2, HCCO, and N2 fragmentation). From product angular and TOF distributions in the lab, product angular and translational energy distributions in the center-of-mass were derived for both channels 1a and 1b. The branching ratio was also derived [1] and found to be in agreement with the most recent, accurate kinetic determinations. Information on the ionization threshold of HCCO (ketenyl) with a well defined internal energy content was obtained by measuring its EI efficiency curve down to 9 eV.

[1] - G. Capozza, E. Segoloni, F. Leonori, G. G. Volpi, and P. Casavecchia, J. Chem. Phys. 120, 4557 (2004); P. Casavecchia, G. Capozza, and E. Segoloni, in "Modern Trends in Chemical Reaction Dynamics", Advanced Series in Physical Chemistry, Ed. by K. Liu and X. Yang (World Scientific, Singapore, 2004), in press. [2] - X. Yang, J. Lin, Y.T. Lee, D.A. Blank, A.G. Suits, A.M. Wodtke, Rev. Sci. Instrum. 68, 3317 (1997). [3] - A.M. Schmoltner, P.M. Chu, and Y.T. Lee, J. Chem. Phys. 91, 5365 (1989).

123

C1-02

Towards the "Universal" Product Detection in Crossed Beam Reactive Scattering Experiments using Soft Electron Impact Ionization: Dynamics of Vynoxy, Acetyl, Methyl, Formyl, and Methylene Radicals and 3 Ketene Formation from the Reaction O( P) + C2H4

G. Capozza, E. Segoloni, G. G. Volpi, and P. Casavecchia Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy

Our understanding of reaction dynamics has benefited greatly of the “universal” capability of the Crossed Molecular Beams (CMB) scattering technique with Electron-Impact (EI) mass spectrometric detection [1]. However, one of the main limitations of EI is known to reside in the dissociative ionization - of reagents, products, and background gases. This can greatly complicate, and even prohibit the identification of products, particularly for multiple channel polyatomic reactions. To overcome this problem, we have very recently introduced, for the first time, the soft EI ionization for product detection [2]. Rather than resorting to soft photoionization (PI) with tunable VUV radiation from a synchrotron, we use EI ionization with tunable (7-100 eV) electrons from a hot filament. This is an attractive alternative to the use of PI by synchrotron radiation, and offers the bonus that branching ratios can be derived since EI ionization cross sections are known or can be estimated. 3 Here we report on the investigation of the reaction O( P)+C2H4, which plays a key role, besides in the combustion of ethylene itself, in the overall mechanism for hydrocarbon combustion. There are five exoergic channels: 3 O( P) + C2H4 → H + CH2CHO ∆H°0 = −13 kcal/mol (2a)

→ H + CH3CO ∆H°0 = −25 kcal/mol (2b)

→ H2 + CH2CO ∆H°0= −85 kcal/mol (2c)

→ CH3 + HCO ∆H°0 = −27 kcal/mol (2d)

→ CH2 + HCHO ∆H°0 = −7 kcal/mol (2e) Since the pioneering work of Cvetanovic in the 1950s many research groups have investigated this reaction, employing a variety of experimental techniques under different conditions of pressure and temperature, identifying only some of the possible products, which has given rise to uncertainties and controversy. By using "soft" EI ionization, we have been able to unambiguously detect the following radical and molecular products, CH2CHO, CH3CO, CH2CO, CH3, and CH2, corresponding to the five reaction pathways (2a-e). From detailed angular and velocity distribution measurements at m/e=42, 15, and 14 using different electron energies, and from measurements of fragmentation patterns, we have characterized the reaction dynamics of all five competing channels and determined the branching ratios. We believe that soft EI ionization, making the so-called universal detection possible, represents a cornerstone in the field and will contribute to establishing a closer link between the kinetics and dynamics of elementary gas-phase chemical reactions.

[1] - P. Casavecchia, Rep. Prog. Phys. 63 (2000) 355, and references therein. [2] - G. Capozza, E. Segoloni, F. Leonori, G. G. Volpi, P. Casavecchia, J. Chem. Phys. 120, 4557 (2004).

124

C1-03

+ Photodissociation of I2 Studied by Velocity Map Imaging

Chen-Lin Liu, Hsu Chen Hsu, and Chi-Kung Ni Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei, Taiwan

+ 2 2 I2 ions in various vibrational states of the ground state X Π3/2 and X Π1/2 spin–orbit components were generated by one photon ionization at 118.222 nm in a molecular beam.

These ions were further dissociated into I+ + I by 532nm photons. The speed and angular distributions of I+ ions were measured by time resolved velocity map imaging. From the speed

+ + 2 distribution of I ions, the vibrational state distributions of I2 ions in the ground state X Π3/2

2 + and X Π1/2 spin–orbit components were identified. The angular distribution of I ions suggests that there is one perpendicular type transition and one parallel type transition

+ corresponding to the 532 nm photon excitation of I2 ions. However, the relative 532 nm absorption probabilities of these two types of transitions change with the initial vibrational states. The possible upper electronic states corresponding to the 532 nm excitation are proposed.

125

C1-04

2 3 − 2 3 Dynamics of Reaction, Y( D3/2, 5/2) + O2(X Σ g) → YO(A Π) + O( PJ), Studied by Crossed Beam-chemiluminescence Technique

Tomohiko Higashiyama, Masayuki Ishida, and Kenji Honma Department of Material Science, Himeji Institute of Technology, Hyogo, Japan

We have studied the reaction of gas-phase yittrium atom with oxygen,

2 3 − 2 3 Y( D3/2,5/2) + O2(X Σ g) → YO(A Π) + O( PJ) (1) by using a crossed beam apparatus. The yittrium atomic beam was generated by laser vaporization and cooled by a carrier gas issued from a pulsed valve. Pure O2 was issued from another pulsed valve, and both beams are skimmed and crossed each other in a reaction chamber. Collision energies studied here are from 17.3 to 52.0 kJ/mol.

Intense chemiluminescence was observed at the crossing region. The chemiluminescence was consisted of YO(A2Π-X2Σ), YO(A'2∆-X2Σ), and YO(B2Σ-X2Σ) transitions. The reasonably high resolution spectra were obtained for the YO(A2Π-X2Σ) transition and were analyzed to determine rotational-vibrational state distributions of

YO(A2Π). The observed chemiluminescence spectra were well represented by the statistical distribution of the product rotational states. The vibrational state distributions were also almost statistical. With a simple consideration of reactant-product state correlation, the formation of a long-lived intermediate complex was suggested for the reaction mechanism.

126

C1-05

Molecular Beam Studies of the Dissociation and Isomerization of Radical Isomers: The Influence of the Electronic Wavefunction in the Dissociation Dynamics of Vinoxy Radicals

J. L. Miller,1 L. R. McCunn,1 M. J. Krisch,1 L. J. Butler,1 and J. Shu 2 1The University of Chicago, Chicago, IL, U.S.A. [email protected] 2Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A.

Photodissociation and reactive scattering experiments test the fundamental assumptions we make in calculating and understanding the rates of chemical reactions via transition state theories: the assumption of the separability of electronic and nuclear motion and the assumption of rapid intramolecular vibrational energy redistribution. Much of our predictive ability for the branching between chemical reaction pathways has relied on statistical transition state theories or, in smaller systems, quantum scattering calculations on a single adiabatic potential energy surface. The potential energy surface gives the energetic barriers to each chemical reaction and allows prediction of the reaction rates. Yet the chemical reaction dynamics evolves on a single potential energy surface only if the Born-Oppenheimer separation of nuclear and electronic motion is valid. This poster and the one presented by L. R. McCunn at the conference describe recent results using our new molecular beam scattering methodology to investigate the internal energy dependence of the unimolecular dissociation and isomerization pathways of selected radical isomers under collision-free conditions. While complementary work in other groups has focused on the photodissociation pathways of radicals, this work probes the unimolecular reactions of radical isomers at lower internal energies where the branching between competing dissociation product channels can be a sensitive function of internal energy. The specific results presented in this poster focus on the unimolecular dissociation channels of the vinoxy radical. In the ground electronic state, vinoxy radicals may dissociate to H + ketene or isomerize to acetyl radicals and dissociate to CH3 + CO. Prior work on this system by Neumark and co-workers evidenced a 4:1 product branching favoring the H + ketene dissociation channel upon exciting the vinoxy radical to the B state. Those workers concluded that the reaction proceeds via internal conversion and modeled the product branching with conventional RRKM theory that assumes the dynamics proceeds adiabatically on the ground electronic state. However, in planar geometries the dissociating vinoxy radical must traverse a conical intersection en route to H + ketene. Thus we undertook to measure the branching between these two dissociation channels as a function of internal energy in the vinoxy radical, expecting to see some reduction of the H + ketene product branching due to nonadiabatic recrossing of the transition state. Using chloroacetaldehyde as a photolytic precursor, the experiments produce nascent vinoxy radicals in the ground state with energies spanning the H + ketene and vinoxy→acetyl isomerization barriers. The surprising results are presented in the poster.

127

C1-06

Mode- and State-selected Photodissociation of OCS+ by Time-sliced Velocity Mapping Image Technique

Chushuan Chang1, Chu-Yung Luo2, and Kopin Liu1,2 1 Department of Chemistry, National Taiwan University, Taipei 106, Taiwan 2 Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan

~ Vibrationally state-selected photodissociatoin of the OCS+( B 2 Σ+ ) molecular ion was investigated by a novel time-sliced velocity mapping image technique[1], which elucidates directly the dynamics of dissociation process without invoking the inverted-Abel

+ ~ 2 (2-dimension to 3-dimension) transformation. A mode- and state-selected OCS ( X Π1/ 2,3/ 2 ) ion was first prepared by a (2+1) resonance-enhanced multiphoton ionization (REMPI)

1 -1 process via the intermediate F ∆(Π1/2) Rydberg state of OCS in the 70500−72500 cm region.

+ ~2 + Predissociation of the vibronically selected level of the OCS ( B Σ ,(ν1, ν2, ν3)) state was

~2 + ~ 2 + ~ 2 initiated by a BΣ ←X Π1/ 2,3/ 2 transition of the initially prepared OCS ( X Π1/ 2,3/ 2 ) from a second laser. The predissociation product ion, S+, was then detected by the time-sliced velocity mapping technique. Rotationally resolved image demonstrated the formation of the

+ 2 1 + + 4 1 + S ( Du) + CO(X Σ , ν, J) product channel, instead of the S ( Su) + CO(X Σ ) pathway as previously suggested by Hubin-Frankskin et. al[2]. Preliminary analysis revealed a dominant bimodal rotational distribution of the CO(X1Σ+ υ = 0) fragment, peaking around J

=10−20 and 46−54, respectively, and relatively minor excited CO(X1Σ+ υ = 1, 2).

[1] J. J. Lin, J. Zhou, W. Shiu, and K. Liu, Rev. Sci. Instrum. 74, 2495(2003) [2] M.-J. Hubin-Frankskin, J. Delwich, P.-M. Guyon, M. Richard-Viard, M. Lavollee, O. Dutuit, J.-M. Robbe, J.-P. Flament, Chem. Phys. 209, 143(1996)

* Work supported by National Science Council of Taiwan under NSC92-2113-M-001-040

128

C1-07

Quasiclassical Trajectory Study of the 193 nm Photodissociation of

CF2CHCl

Emilio Martínez-Núñez and Saulo A. Vázquez Departamento de Qímica Física, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain

Quasiclassical trajectory calculations were performed to calculate product energy distributions for the HF and HCl elimination reactions in the photodissociation of CF2CHCl at

193 nm. The trajectories were integrated “on the fly” by using density functional theory

(DFT). In particular, we used the BLYP functional with parameters adjusted to reproduce high level ab initio data corresponding to the stationary points in the exit channels. The trajectories are initiated at the relevant transition states, using a microcanonical, quasiclassical normal-mode sampling. Comparison with the available experimental results is discussed.

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1 Reinvestigation of O( D)+H2O Reaction: Examination of the Contribution of Excited States

Yo Fujimura, Hisashi Tamada, Yoshiyuki Imai, Kazuya Mitsutani, and Okitsugu Kajimoto Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan

1 We have examined the contribution of the excited states in the O( D)+H2O reaction by measuring rovibrational state distribution of OH products up to the energetically accessible highest vibrational level (v′=3) at the average collision energy of 42 kJ/mol. Influence of the excited states originating in the five-fold degeneracy of O(1D) atom is one of current important issues of the O(1D) reactions. Recent high-level ab initio calculations for

1 1 O( D)+H2 [1] and O( D)+HCl [2] reactions show low entrance barrier less than 10 kJ/mol for the first excited state, and experimental observations agree well to these calculated results [3].

However, little is known about the larger system such as the title reaction. Although the influence of the excited states is expected to be most discernible in high vibrational levels of the OH products due to the abstraction nature in the excited state surfaces of the O(1D) reaction, the observed vibrational distribution smoothly decreases with the increase of the vibrational quantum number and no clear evidence of the contribution of the excited state is detected. We have estimated that the contribution of the excited states is at most 10% from a surprisal analysis under the collision energy employed in this study.

[1] G. C. Schatz, A. Papaioannou, L. A. Pederson, L. B. Harding, T. Hollebeek, T.-S. Ho, and H. Rabitz, J. Chem. Phys. 107, 2340 (1997). [2] S. Nanbu, M. Aoyagi, H. Kamisaka, H. Nakamura, W. Bian, and K. Tanaka, J. Theor. Compt. Chem. 1, 263 (2002). [3] Y.-T. Hsu, J.-H. Wang and K. Liu, J. Chem. Phys. 107, 2351 (1997).

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Photodissociation Dynamics Investigated with a Pulsed Slit-jet and Time-resolved Fourier-transform Spectroscopy Mohammed Bahou1 and Yuan-Pern Lee1,2 1Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan

Among the photodissociation channels of vinylchloride CH2CHCl at 193nm there are two competing pathways for HCl elimination, namely the three-center (α,α) and four-center (α, β) molecular elimination. Because the transition states involved in each reaction path is distinct, the internal energy distribution of resultant photofragments is expected to reflect these differences [1-3]. Step-scan time-resolved Fourier-transform spectroscopy (TR-FTS) has been demonstrated to be powerful in determining internal energy distributions of reaction products as compared with other techniques. Following photodissociation of vinyl chloride seeded in a He supersonic jet at 193 nm, rotationally resolved infrared emission of HCl(v) are recorded to yield nascent rotational and vibrational distributions. Preliminary results show that rotational distributions of HCl free from rotational quenching and nearly Boltzman-type for v = 1−4; they are compared with previous experimental results determined with a flow system [2], and recent classical trajectory calculations [4]. Observed rotational distributions agree well with trajectory calculations; a major fraction of the low-J component observed previously in a flow system is likely due to quenching. The implication in photodissociation dynamics is discussed. [1] Y.-P. Lee, Ann. Rev. Phys. Chem. 54, 215 (2003). [2] S.-R. Lin, S.-C. Lin, Y.-C. Lee, Y.-C. Chou, I-C. Chen, and Y.-P. Lee, J. Chem. Phys. 114, 160 (2001). [3] S.-R. Lin, S.-C. Lin, Y.-C. Lee, Y.-C. Chou, I-C. Chen, and Y.-P. Lee, J. Chem. Phys. 114, 7396 (2001). [4] E. Martínez-Núñez, A. Fernández-Ramos, S. A. Vázquez, F. J. Aoiz, and L. Bañares, J. Phys. Chem. A107, 7611 (2003).

131

C1-10

Ab Initio Studies for Dissociation Pathway and Isomerization of Crotonaldehyde Sheng-Jui Lee and I-Chia Chen Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300

Dissociation and isomerization reactions of singlet and triplet crotonaldehyde are investigated using ab initio calculations. Geometries and frequencies of intermediates, transition states, and fragments are optimized at level B3LYP/6-311++G(d,p); accurate energetics for some optimized geometries are obtained at CCSD(T)/6-311G(d,p). The transition states of all channels are checked by IRC method. Up to five dissociation pathways are investigated: H atom elimination, HCO elimination, CH3 elimination, CO elimination, and H2CO elimination and four isomerization processes are found:

1,3-Butadienol, 3-Butenal, Ethylketene, and CH3CHCH2CO. On the singlet surface, crotonaldehyde can undergo isomerization to 3-butenal directly or to 1,3-butadienol first then converted to 3-butenal via a two-step process. Dissociation to H2CO + propyne and CO + propene is correlated to the ground electronic surface and via an exit barrier. In addition, isomer ethylketene can also dissociate to form CO + propene. On triplet surface, four optimized structures of T 3(n-π*) and two of T 3(π-π*) with a twisted geometry are obtained.

3 * On T1 (π-π ) elimination to CH3 with a barrier and isomerization to ethylketene are found.

3 * On T2 (n-π ) H elimination channel and fragmentation to HCO with an exit barrier and isomerization to CH3CHCH2CO first then dissociation to CO + triplet propene are found.

Isomers 1,3-Butadienol and 3-Butenal can undergo dissociation to form fragments allyl radical + HCO.

132

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The Use of Ultrafast Photodissociation as a Probe for Studies of Electronic Energy Transfer Dynamics

Jr-Wei Ho, Chia-Ming Yang, Ta-Jen Lai and Po-Yuan Cheng* Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan

Electronic energy transfer (EET) is one of the most important elementary steps in chemistry and biology. Conventional methods used in studies of EET usually involve the use of fluorescence as a probe. Here, we have employed a different approach in which ultrafast dissociation occurring in model systems was used as a probe to investigate the EET dynamics.

In this study a series of compounds, Ph-(CH2)n-I n=0-2, are excited by femtosecond (fs) laser pulses at 200 nm to one of their high-lying (π,π*) states that is largely localized in the phenyl ring region. The systems then evolve to cross to an energy-accepting (n,σ*) state with purely repulsive characteristics localized along the C-I bond, leading to an ultrafast elimination of the iodine atom. By monitoring the formation of free iodine atoms in real time, the EET dynamics between the initially excited (π,π*) and the C-I(n,σ*) states in these three compounds have been revealed.

133

C1-12

The Role of Radical-Molecule Complexes in the Recombination Kinetics of Benzyl Radicals

Kawon Oum, Kentaro Sekiguchi and Klaus Luther Institut für Physikalische Chemie, Universität Göttingen, Tammannstr. 6, D-37077 Göttingen, Germany

Radical combination reactions are usually considered to proceed by the dynamical interplay of the interactions between the radical reagents (R+R) and collisional energy transfer of their * adduct with the bas gas (R2 + M). This leads to the well known pressure dependence at low ET densities and a limiting value “k∞ ” – independent of the nature and pressure of the gas – at sufficient high gas densities. A dynamically distinctly different mechanism, involving radical-bathgas complexes RM as one or both reagents, was identified long time ago in atom plus atom recombination, but it was thought that it would only play a role in small, diatomic systems if usual weak interactions RM of the van der Waals type are involved. However recently we found experimental evidence in extended high pressure studies which point at the presence of the radical-complex mechanism already for larger radicals of up to four atoms (CCl3)[1].

We now report extended studies on the pressure and temperature dependence of the benzyl recombinations kinetic in various bath gases (CO2, Ar, N2, Xe, He, CF3H). Time resolved UV absorption techniques were used to monitor kinetics over a wide range of pressures (1–1000 bar) at temperatures of 250–400 K in an optical high pressure and high temperature flow cell. Benzyl radicals (PhCH2) were produced from reactions of toluene with Cl following excimer laser photolysis of Cl2 at 308 nm: Cl2 + hν → 2 Cl; Cl + PhCH3 → PhCH2 + HCl.

We chose benzyl as an example of a large organic radical. Its recombination reaches the ET pressure independent rate constant k∞ already in the range of 10 mbar. However following two decades of pressure independent behaviour we observe a surprising new increase of the rate constants with density, starting at pressures of several bar[2]. At very high densities a final decrease of the rate constants due to limitations by diffusion was observed as expected.

The experimental dependence of the unusual increase of reaction rates on the choice of bathgases M and the temperature indicates very strongly that we observe the signature of RM complex dynamics in benzyl recombination under conditions when it starts to govern the overall kinetics. Detailed evidence will be presented and consequences will be discussed.

[1] K. Oum, K. Luther and J. Troe, J. Phys. Chem. A 108, 2690 (2004). [2] K. Oum, K. Sekiguchi, K. Luther and J. Troe, Phys. Chem. Chem. Phys. 5, 2931 (2003).

134

C1-13

Reactions of •OH and H• with Aliphatic Alcohols: A Pulse Radiolysis Study

M. S. Alam1,2,3, B. S. M. Rao2 and E. Janata1

1Hahn-Meitner-Institut Berlin GmbH, Bereich Solarenergieforschung Glienicker Str. 100, 14109 Berlin, Germany 2National Centre for Free Radical Research, Department of Chemistry University of Pune, Pune-411007, India 3Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan

The study of reactions of hydroxyl radicals or hydrogen atoms with various alcohols is quite common in pulse radiolysis. The alcohols are used as a scavenger in order to simplify the redox system. Or, the reaction of the subsequently formed alcohol radicals with a variety of substrates is investigated. The rate constants for the reactions of hydroxyl radicals or of hydrogen atoms with various alcohols were earlier determined by interpreting competition reactions [1], or by following the decay of the hydrogen atom using EPR techniques [2]. Here, we present the evaluation of rate constants based on measurements of the optical absorption in the UV-range [3,4] of the respective alcohol radicals. They are generated in aqueous solutions either at pH1 and purged with argon or at natural pH and saturated with nitrous oxide and containing various primary, secondary, or tertiary alcohols. The absorption of alcohol radicals generated from secondary and tertiary alcohols differ depending on the pH value, unlike that of primary alcohols. The relevant reaction mechanisms at natural pH and at pH1 are discussed.

[1] P. Neta, G. R. Holden, R. H. Schuler, J. Phys. Chem. 75, 449, 1971. [2] S. P. Mezyk, D. M. Bartels, J. Phys. Chem. A. 101, 1329, 1997. [3] M. S. Alam, B. S. M. Rao, E. Janata. Phys. Chem. Chem. Phys. 3, 2622, 2001. [4] M. S. Alam, B. S. M. Rao, E. Janata. Radiat. Phys. Chem. 67, 723, 2003.

135

C1-14

Substituent Effect on Structure and Bonding of Bertrand Diradical (X2P)2(BY)2

Mu-Jeng Cheng and San-Yan Chu

Department of Chemistry, National Tsing Hua University, Hsinchu 30013,

Theoretical study of a series of X2B2P2H4 and H2B2P2Y4 (X, Y= F, Cl, CH3, H, SiH3), the

Bertrand type diradical, shows that the stronger the σ-acceptor substituent for X or Y, the smaller the inversion barrier Ea, the energy gap between the long-bond isomer (1) and the short-bond isomer (2). The σ-acceptor substituent also increases the ∆ES-T, the energy splitting between the singlet and triplet state of the long-bond isomers. Thus it reduces the diradical character for the long-bond isomer from the CASSCF wavefunction analysis. The replacement of boron with aluminum atom in H2B2P2H4 will lower the symmetry of the long-bond isomer from D2h to C2h with a dramatic increase in diradical charcater. This phenomenon can be explained by the weakening in the through-space π-bond interaction from

B-B to Al-Al.

X Y Y

Y B Y P P 1 Y P P Y BB Y B Y 1 X 2 X 2 2 X

136

C1-15

Characterisation of the CCl2 Ã State Joseph Guss and Scott Kable University of Sydney

We have recorded the laser induced fluorescence spectrum of A-X transition of jet-cooled -1 -1 CCl2 from 18,000 cm to 24,000 cm . Dispersed fluorescence (DF) spectra from over 100 single vibronic levels have allowed us to make secure rotational, vibrational and isotopic assignments of the emitting state. The spectroscopy of the A-X transition can be understood by considering three different regions: Region 1 (up to ~20,300 cm-1): Assignments in this region, in terms of vibrational quanta, are straightforward. The relative peak intensities (Franck-Condon factors) in the DF spectra confirm these assignments. Region 1 is essentially the limit of previous assignments. Region 2 (from ~20,300 cm-1 to ~22,500 cm-1) has a similar appearance to Region 1; however, the DF spectra are now not well modeled by a single set of FCFs. This suggests Fermi resonance between different vibrational levels. The near resonance between two quanta of bend and one quantum of symmetric stretch allows coupling of vibrational levels. The extent of mixing becomes quickly complete such that a label in terms of bending and stretching quanta is meaningless. Region 3 (from ~22,500 cm-1 to ~24,000 cm-1) is characterised by a markedly different rotational structure. High resolution DF spectroscopy allows us to uniquely identify the K state from which emission occurs. In Region 3 we almost exclusively observe K = 0 lines (unlike Regions 1 and 2 where all vibrational bands comprised several distinct K sub-bands). In this region we believe the energy is above the Renner-Teller intersection with the ground state. ~ We have modeled the A state potential energy surface using the “ab initio potential morphing” technique of Meuwly and Hutson. Briefly, ab initio calculations are undertaken at a level of theory sufficient to produce a surface with a qualitatively correct shape. This surface is then “morphed” with a scaling function that bends and stretches the ab initio surface to fit experimental observables, in this case, energy levels. The derived PES surface not only matched the observed energies, but explains the origin of the three Regions in the spectrum.

137

C1-16

Assessment of Training Effects on Levels of Serum Total Anti-oxidative Activity in Matured Rats using Luminol-dependent Chemiluminescence

Takashi Kumae1 and Hatsuko Arakawa2 1National Institute of Health and Nutrition, Tokyo, Japan 2National Institute of Public Health, Wako, Japan

There are many papers dealing with reactive oxygen species generated In Vivo during physical activities. To estimate a balance between oxidative radicals and anti-oxidative systems in a living body, we developed a simple measurement method of total anti-oxidative activity (TOA) in biological samples using luminol-dependent chemiluminescence [1]. We divided rats into following two groups; one group of rats started training at 11 weeks old (Group A) and another group started at 17 weeks old (Group B). Each group was divided into 4 sub-groups: 1) forced training group; exercised on a treadmill, 2) voluntary training group; housed separately with running wheel, 3) control of voluntary training group; housed separately without running wheel, and 4) control group; housed under sedentary condition. After 6- or 12-week training, the rats were anesthetized, and bloods were collected from abdominal aorta. To measure serum TOA, we used stable peroxide (SuperSignal ELISA Piko Chemiluminescent Substrate (Pierce)) and horseradish peroxidase as a radical source. A parallel luminometer (Alpha-Basic 47, Tokken) was used to measure the chemiluminescence [2]. Serum vitamin C, non-protein glutathione, glutathione reductase activity, glutathione peroxidase activity, and thiobarbitric acid reactive materials (TBAR) were measured and 20 items of general serologic tests were achieved. According to aging, vitamin C levels in the control groups were significantly decreased. In Group B, the forced and voluntary training groups showed significantly increased levels of TAO along with decreased levels of TBAR than the levels in the control group after 12-week training. These results suggest that TAO is useful to evaluate the training effects on the oxidative and anti-oxidative balance. [1] T. Kumae, K. Machida,S. Nakaji, and K. Sugawara, J Phys. Fit. Nutr. Immunol. 13, 227-229 (2004). [2] T. Kumae and H. Arakawa, Luminescence 18, 61-66 (2003).

138

C1-17

High Resolution Spectroscopy and Reaction Dynamics of Free Radicals

Feng Dong, Erin Whitney, Alex Zolot, Mike Deskevich, and David J. Nesbitt JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440, U.S.A.

The combination of i) shot noise limited (< 10-6/Hz1/2) direct absorption IR laser spectroscopy with ii) supersonic slit discharge expansions provides a powerful window into detailed study of highly reactive free radicals in the gas phase at low temperatures. First of all, we will present recent results on high resolution rovibrational spectropscopy of organic free radicals such as cyclopropyl, which has been detected for the first time in the gas phase by direct absorption in the CH stretch region. Of special interest is the presence of quantum mechanical tunneling between the two non-planar conformations of the lone CH radical group, which is easily resolved in these studies and provides direct information on barrier heights to isomerization between the two conformers. A second topic will be the use of direct IR laser absorption methods to probe quantum state-resolved dynamics in crossed molecule beams. This method has been used to probe several prototypic hydrogen abstraction reaction systems, from atom + diatom, where direct comparison with theory can be made, to atom + polyatom, where the dynamics can in principle be far more complicated. For the specific test case of F + ethane, product state distrubutions and Doppler profiles reveal a remarkably strong correlation between i) recoil velocies of the nascent HF fragment and ii) Eavailable for the co-product. The analysis indicates ”impulsive mode” funneling of the reaction exothermicity into rotation of the ethyl radical, and suggests that the essential reaction dynamics for many exothermic atom + polyatom systems can be understood from extensions of the Polanyi rules.

139

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FTMW and FTMW-MMW Double Resonance Spectroscopy of the CH3OO Radical

1) 1) 1) 2) Kaoru Katoh , Yoshihiro Sumiyoshi , Yasuki Endo , and Eizi Hirota 1) Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan 2) The Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, Japan

RO2·(R = CH3, C2H5, etc.) radicals play very important roles in atmospheric and combustion chemistry. However, laser induced fluorescence spectroscopy cannot be applied to detect these radicals since the RO2· radicals have no fluorescent states, and thus only limited spectroscopic data are available for these radicals. In the present study, pure rotational transitions of CH3OO with resolved spin splittings and hyperfine splittings due to the H nuclei have been observed by Fourier-transform microwave (FTMW) spectroscopy and FTMW-millimeter wave (MMW) double resonance spectroscopy. The 101 – 000 transitions in the 21 GHz region have been observed by FTMW spectroscopy, and the 202 – 101 transitions in the 42 GHz region have been observed by applying FTMW-MMW double resonance spectroscopy, where the 101 – 000 transitions are monitored by a FTMW spectrometer. The radical was produced in a supersonic jet by a pulsed electric discharge of a mixture gas of CH3COCH3 and O2 diluted to 0.3% with Ar. The discharge voltage was about 1.5 kV. The a-type transitions, 101 – 000 and 202 – 101 in both the A and E states with fine and hyperfine structure, have been simultaneously fit with the experimental accuracy to a Hamiltonian formulated by the Rho axis method (RAM)[1]. Fig.1 shows the rotational energy level structure determined by the least-squares analysis. The potential -1 barrier V3 is determined to be 343 cm , which is higher than that of an ab initio calculation, 330 cm-1, at the RCCSD(T)/cc–pVTZ level of theory. It was found that the 202 and 110 states are very close, and a strong interaction occurs between the states with J = 3/2. To clarify the interaction, observations of the b-type transitions, 110 – 101 and 111 – 000, for the A and E states are in progress. [1] J. T. Hougen, I. Kleiner, and M. Godefroid, J. Mol. Spectrosc. 163, 559 (1994)

140

C2-02

Geometric Phase and the Hydrogen-Exchange Reaction

Juan Carlos Juanes-Marcos and Stuart C. Althorpe Department of Chemistry, University of Exeter Exeter, EX4 4QD, UK

The Hydrogen-Exchange reaction is the simplest reaction that has a conical intersection, and this has sparked a lively debate as to whether the dynamics is influenced by Geometric Phase

(GP) effects. We have recently performed the first time-dependent wave packet calculations to include the GP vector potential [1], in order to predict how the GP influences the reaction dynamics, and the (experimentally measurable) cross sections. Overall, our results reproduce recent predictions made by Kendrick [2], which are that the GP effect causes changes in the fixed-J opacity functions, but that these changes cancel upon summing over partial waves in the cross sections. We find [3] that most of the wave packet does not encircle the conical intersection. However, we also find that, at higher total energies (typically >1.8 eV), there are significant shifts produced by the GP in the oscillatory patterns that are present in some of the state-to-state differential cross sections. We will discuss recent work aimed at uncovering the origin of these patterns, which may provide a means of probing experimentally the onset of GP effects in the hydrogen-exchange reaction.

[1] C.A. Mead, D.G. Truhlar, J. Chem. Phys. 70, 2284 (1979).

[2] B.K. Kendrick, J. Phys. Chem. A 107, 6739 (2003).

[3] J.C. Juanes-Marcos, S.C. Althorpe, Chem. Phys. Lett. 381, 743 (2003).

141

C2-03

~1 Polarization Quantum Beat Spectroscopy of HCF( A A′′): 19F and 1H Hyperfine Structure, Zeeman Effect, and Singlet-triplet Interactions

Haiyan Fan,1 Ionela Ionescu,1 Chris Annesley,1 Ju Xin,2 and Scott A. Reid1 1Department of Chemistry, Marquette University, Milwaukee, WI 53201 2Department of Physics and Engineering Technologies, Bloomsburg University, Bloomsburg, PA 17815 To investigate the 19F and 1H nuclear hyperfine structure and Zeeman effect in the simplest singlet carbene, HCF, we recorded quantum beat spectra (QBS) of the pure bending ~ 1 ~ 1 levels (0,υ2′,0) and combination states (1,υ2′,0) and (0,υ2′,1) in the HCF A A′′ ←X A′ system. The spectra were measured under jet–cooled 20 conditions using a pulsed 15 discharge source, both at 10 zero-field and under y application of a weak 5 magnetic field (< 30 G). Analysis yielded the 19F and 0 1 H nuclear spin-rotation -5 constants (C ) and weak aa intensit Fluorescence -10 field Lande gaa factors.

Consistent with theoretical -15 expectations, a linear -20 correlation of Caa and gaa is 0123456 observed for the majority of Time in µs vibrational levels, from Fig. 1. Fluorescence transients obtained following r excitation of the R0(0) transition in the (0,1,1) level of which the hyperfine constants ~ 1 HCF(A A′′ ), for parallel and perpendicular laser-detection 19 1 for the F and H nuclei were polarizations. determined. We will highlight the utility of polarization QBS for the study of singlet-singlet (i.e., Renner-Teller) and singlet-triplet interactions in this system.

142

C2-04

Two-color Resonant Four-wave Mixing Spectroscopy of Highly 2 Predissociated Levels in the à A1 State of CH3S

Ching-Ping Liu1, Scott A. Reid2 and Yuan-Pern Lee1, 3 1Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 30013 2Department of Chemistry, Marquette University, Milwaukee, WI 53201 3Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106

We report a two-color resonant four-wave mixing study of highly predissociated levels in the first excited electronic state of thiomethoxy radical, CH3S. The spectra were measured under jet-cooled conditions following 248 nm laser photolysis of dimethyl disulfide, in a 3 hole-burning geometry where the probe laser excited specific rotational lines in the 30 band. The spectral simplication afforded by the two-color method 1 4 allowed accurate determination 2 3 of band positions and Γ=4.6(2) 1 homogeneous linewidths, which are reported for the C-S n stretching states 3 (n=0-7) and Relativeintensity 1 n combination states 1 3 (n=0-2), 1 n 1 1 n 2 3 (n=3-6), and 1 2 3 (n=0,1).

The spectra show pronounced 29145 29150 29155 29160 mode specificity, as the Wavenumber (cm-1) homogeneous linewidth of nearly Figure 1. Two-color resonant four wave mixing spectrum of the 2134 level (open circles) and the results of a fit (line) isoenergetic levels often varies which yielded a homogeneous linewidth of 4.6(2) cm-1. by 1-2 orders of magnitude, with

υ3 a clear promoting mode for dissociation. The derived à state vibrational frequencies ω1′,

ω2′, and ω3′ are in excellent agreement with ab initio predictions.

143

C2-05

Exploring the Potential Energy Surfaces of C3

K. Ahmed, G. G. Balint-Kurti and C. M .Western School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS UK

~1 ~ 1 + The spectroscopy of the A Πu − X Σ g transition in the C3 radical has a remarkably long history, dating back to 1881 when the ultraviolet emission was first seen in the spectra of comets. The system is very complicated and, despite many spectroscopic studies, the basic analysis was only completed in 1995 by Izuha and Yamanouchi[1] when the asymmetric stretch, ν3, in the excited state was determined. This shows a double minimum potential in the excited state, and the analysis is further complicated by a strong Renner-Teller interaction in the excited state and a very low (63 cm–1) bending frequency in the ground state. In this poster we present a new determination of the potential energy surfaces for the ground and first excited states, starting from a Ab initio Symmetric Stretch Potential surface obtained from high level ab initio / cm–1 calculations and then fitting the most important 80000 parameters to experimental data. It is clear from 70000 the ab ibitio calculations that much of the 60000 complications in the excited state arise from 1 50000 Πg crossings with a pair of states ( 1Σ− and 1 ∆ ) 1 – 1 u u Σu , ∆u ~ 40000 4500 cm–1 above the A state origin and an 1 –1 30000 additional crossing with a Πu state at 6500 cm . A 1Π We present a fit of the ground state potential up 20000 u –1 to 7500 cm which reproduces 85 observed 10000 1 + X Σ g levels to 5 cm–1 and a fit to the excited state 0 below the first crossing which reproduces 39 1.05 1.15 1.25 1.35 1.45 1.55 –1 observed levels to 5 cm . r 1 = r 2 / Å

[1] M. Izuha and K. Yamanouchi, Chem. Phys. Lett. 242, 435 (1995)

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C2-06

~ Perturbations in the A1Πu, 000 Level of C3 Guiqiu Zhang,1,2 Kan-Sen Chen,1 Anthony J. Merer,3 Yen-Chu Hsu,1,4 Wei-Jan Chen,1,5 Shaji Sadasivan,1 Yean-An Liao,1 and A. H. Kung1 1Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan, R. O. C. 2 Dept. of Chemistry, Shandong Normal Univ., Jinan 250014, People’s Republic of China 3 Dept. of Chemistry, University of British Columbia, Vancouver, B. C., Canada V6T 1Z1 4 Department of Chemistry, National Taiwan University, Taipei, Taiwan, R. O. C. 5Department of Physics, National Central University, Chung-Li 32054, Taiwan.

0 1 Rotational analyses have been carried out for the (0,0), 11 , and 11 bands of the ~1 ~ 1 + A Π u −X Σ g system of C3, from high resolution (ring laser) spectra taken under supersonic jet-cooled conditions. Two different measurements have been taken for each band, with time gatings of 20-150 ns and 800−2300 ns. At short time delays the spectra are similar to those recorded by Gausset et al. [1], and by many other workers [2], but at long time delays a 0 number of new lines appear in the (0,0) and 11 bands, some of which have also been observed by McCall et al. [3] Analysis shows that there are two long-lived states perturbing ~1 −1 ~ the A Π u , 000 level at low J values. One of these lies about 1.5 cm above the A , 000 ~ level and appears to be part of a case (b) triplet state; its B value is similar to that of the A , 000 level. The other appears to be a P=1 level, which is almost degenerate with the 000 level for low rotational quantum numbers, but has a much lower B value such that it drops rapidly below it with increasing rotation; it has a surprisingly large P-type doubling. Vibrational assignments of the perturbing states have not yet been possible. Our new spectra confirm the revised rotational assignment of the R(0) line of the ~1 ~ 1 + A Π u −X Σ g , (0,0) band given by McCall et al. [3] This new assignment is consistent with astrophysical spectra of C3 recorded in absorption by Maier et al. [4] towards various stars, which indicate the presence of C3 in the interstellar medium. [1] L. Gausset, G. Herzberg, A. Lagerqvist and B. Rosen, Astrophys. J. 142, 45(1965). [2] (a). A. J. Merer, Can. J. Phys. 45, 4103 (1967); (b). W.J. Balfour, J. Cao, C.V.V. Prasad and C.X.W. Qian, J. Chem. Phys. 101, 10343 (1994); (c). J. Baker, S. K. Bramble and P. A. Hamilton, J. Mol. Spectrosc. 183, 6 (1997). [3] B. J. McCall, R. N. Casaes, M. Ádámkovics and R. J. Saykally, Chem. Phys. Lett. 374, 583 (2003). [4] J. P. Maier, N. M. Lakin, G. A. H. Walker and D. A. Bohlender, Astrophys. J. 553, 267 (2001).

145

C2-07

Partial Quenching of Orbital Angular Momentum in the OH-Acetylene Complex

Mark D. Marshall,1 Margaret E. Greenslade,2 James B. Davey,2 and Marsha I. Lester2 1Department of Chemistry, Amherst College, Amherst, MA 01002-5000 USA 2Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323 USA

The entrance channel leading to the addition reaction between the hydroxyl radical and acetylene has been examined by spectroscopic characterization of the OH-acetylene reactant complex. Infrared action spectra have been recorded in the OH overtone [1] and asymmetric CH stretch regions, with a UV probe laser detecting the OH fragments produced upon vibrational predissociation of the complex. Analysis of the rotationally resolved OH overtone band (a-type) at 6885.5 cm-1 yields the (B+C)/2 rotational constant and confirms the T-shaped, π-hydrogen bonded structure predicted by ab initio theory. The asymmetric CH stretch spectrum centered at 3278.6 cm-1 consists of seven peaks of various intensities and widths. This spectrum is very different from those previously reported for similar HF/HCl-acetylene complexes. A model has been developed to examine the origin of this unexpected result, namely partial quenching of the OH orbital angular momentum in the complex.[2] The significant splitting of the OH monomer orbital degeneracy into 2A' and 2A'' electronic states in the complex is shown to be responsible for the quenching, a process that must occur as the system evolves from weakly interacting partners to the addition product. The model has been successfully applied to the analysis of the observed infrared bands of the OH-acetylene complex, and allows the determination of the A rotational constant and difference potential from the b-type, CH stretching band. In addition, the stability of the complex is deduced from the OH product rotational state distributions. Results obtained in -1 both spectral regions are consistent with D0 ≤ 950 cm .

[1] J. B. Davey, M. E. Greenslade, M. D. Marshall, M. I. Lester, and M. D. Wheeler, J. Chem. Phys., in press (2004). [2] M. D. Marshall and M. I. Lester, J. Chem. Phys., submitted for publication (2004).

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Infrared Spectroscopy of Large-sized Protonated Water Cluster Cations: Development of the 3-Dimensional Hydrogen Bond Network with Cluster Size

Asuka Fujii, Mitsuhiko Miyazaki, Takayuki Ebata, and Naohiko Mikami Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan

Development of hydrogen bond network with cluster size has been one of the most attractive subjects in molecular cluster chemistry. Recently infrared (IR) spectroscopy has been applied to molecular clusters produced in a molecular beam, and cluster structure determination can be carried out with a help of ab initio calculations. In such studies, however, cluster sizes have been limited to less than 10 molecules, and only very early stages of 1 hydrogen bond network development have been observed. In this paper, we present IR spectra of size-selected protonated water cluster cations, + 2 H (H2O)n, from n=4 to n=27 in the OH stretching vibrational region. Both of hydrogenbonded and free OH stretch bands smoothly change their features with increase of the cluster size, reflecting the development of the hydrogen bond network among the water molecules. Detailed analysis of the spectra indicates that the radial chain structures with the + + H3O or H5O2 core in the small sizes grow into the 2-dimensional hydrogen bond net structures at n=7-10, and then the 3-dimensional cage structures become predominant in n=21, + which is a well-known magic number in mass spectra of H (H2O)n. This is the first experimental characterization of the structures of large-sized clusters involving more than 10 water molecules. The predominance of the 3-dimensional cage structures in n>20 is consistent 3 with the previous ab initio prediction of the dodecahedral cage structures for n=21. IR + 4, 5 spectra and structure of [Benzene-(H2O)n] cluster cations (n=1-23) will also be discussed. References 1. J. -C. Jiang, Y. -S. Wang, H. -C. Chang, S. H. Lin, Y. T. Lee, G. Niedner-Schatteberg, and H. -C. Chang, J. Am. Chem. Soc. 122, 1398 (2000). 5. M. Miyazaki, A. Fujii, T. Ebata, and N. Mikami, Science in prerss. 3. A. Khan, Chem. Phys. Lett. 319, 440 (2000). 4. M. Miyazaki, A. Fujii, T. Ebata, and N. Mikami, Chem. Phys. Lettt. 349, 431 (2001). 5. M. Miyazaki, A. Fujii, T. Ebata, and N. Mikami, Phys. Chem. Chem. Phys. 5, 1137 (2003).

147

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Electronically-excited Singlet States of LiH

Wei-Tzou Luh Department of Chemistry, National Chung Hsing University 250 Kuo-Kuang Road, Taichung 402, Taiwan

Electronically-excited singlet states of isotopic lithium hydrides lying in the range of 5.8-6.4 eV are investigated via a pulsed optical-optical double resonance spectroscopic technique. For the D 1Σ+ state, observed OODR line shapes for some vibrational levels are of asymmetric, Fano-type profile. Observed line widths (HWHM) change dramatically as the vibrational quantum number varies [1], they are among the range 0.1 - 12.5 cm-1 for 7LiH, 0.1

- 10 cm-1 for 7LiD, compared to the theoretical results, 0.0008 - 37.5 cm-1 for 7LiH, of

Gemperle and Gadea [2]. The observed asymmetric profile is attributed mainly (a) to the D

1Σ+ - C 1Σ+ bound-free nonadiabatic radial coupling strength, and (b) to the relative ratio between the D1Σ+-A1Σ+ bound-bound oscillator strength and that for the C1Σ+-A1Σ+ free-bound excitation. The observed line width is mainly attributed to the D 1Σ+ - C 1Σ+ bound-free nonadiabatic radial coupling strength. Recent spectral results for higher electronic states, E1Σ+, I1Π, J1Π, and K1∆, will be also presented.

[1] Y.L. Huang, W.T. Luh, G.H. Jeung, F.X. Gadea, J. Chem. Phys. 113, 683 (2000).

[2] (a) F. Gemperle, F.X. Gadea, Europhys. Lett. 48, 513 (1999); (b) private communication.

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Intracavity Laser Spectroscopy of NiH

Leah C. O’Brien1and James J. O’Brien2 1Southern Illinois University, Edwardsville, IL, USA 2University of Missouri, St Louis, MO, USA

The visible electronic transitions of NiH have been recorded with rotational resolution by intracavity laser absorption spectroscopy. The gas phase NiH molecules were produced in an electric discharge using a nickel cathode in a pure hydrogen atmosphere at 1-4 torr total pressure. Results of the analysis will be presented. 58NiH and 60NiH have been observed in sunspots [1] and attempts to observe NiH in stellar spectra are underway [2].

[1] Malia and Lambeth [2] G. Wallerstein, personal communication.

149

C2-11

Spectroscopy of Si+NH3 and Si+PH3 Reaction Products: Rovibronic Structure of the Ground Electronic States of SiNSi and PH2

Zygmunt J. Jakubek, Sanjay Nakhate1, Benoit Simard*, and Mirek Zachwieja2 Steacie Institute for Molecular Sciences, National Research Council, Ottawa, Canada

The SiNSi and PH2 molecules were produced by laser ablation of Si in the presence of

NH3 and PH3, respectively, and studied in a free jet by the resonant two-photon ionization (R2PI), laser induced fluorescence (LIF), dispersed fluorescence (DF), and stimulated emission pumping (SEP) techniques. SiNSi. Mass-analyzed R2PI spectra of SiNSi were recorded in order to identify the carrier molecule and confirm the previous observation of Brugh and Morse (D. J. Brugh, M. D. Morse, Chem. Phys. Lett. 267, 370 (1997)). LIF excitation spectra were recorded with a 0.2 cm-1 resolution over 32660-36500 cm-1 range and with higher resolution (0.03 cm-1) for selected bands. For most excitation bands, DF spectra were recorded (3-7 cm-1 resolution) in the range of up to 4000 cm-1 to the red and 1500 cm-1 to the blue of the excitation line. Over

20 zero-bending vibronic levels, (ν10ν3) with ν1≤7 and ν3≤3, and 20 Renner-Teller levels, 2 (0ν20) with ν2≤4, were identified in the X Πg ground electronic state. The upper levels of the 2 + 2 - excitation spectra were assigned to 2 electronic states, Σu and Σu . -1 PH2. The LIF excitation spectra of PH2 were recorded (~0.04 cm resolution) in the 2 2 vicinity of the (040)-(000) A A1-X B1 band (F. W. Birss et al. J. Mol. Spectrosc. 92, 269 (1982)). DF spectra were recorded (5-7 cm-1 resolution) in the range of up to 7000 cm-1 to 2 the red from the excitation line. Eight new vibrational levels of the X B1 ground electronic state, (ν1ν2ν3) with ν1, ν2, ν3≤2, were observed. The SEP spectra were obtained by exciting 2 selected rotational levels of the (040) A A1 level (pump) and stimulating with the second laser 2 delayed by 180 ns transitions (dump) to the (100) and (001) levels of the X B1 ground electronic state, while fluorescence to the (000) level was monitored. Pulse-to-pulse signal normalization was used with the SEP and reference signals measured on the same excitation pulse. Twenty-four rotational levels belonging to the (100) and (001) vibrational levels of the ground electronic state were observed and their term values were determined with ~0.1 cm-1 accuracy.

1 On leave from: Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai, India. 2 On leave from: Physics Institute, University of Rzeszow, Rzeszow, Poland

150

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Isotope Dependence and Born-Oppenheimer Breakdown in Mid- and Far-Infrared Spectra of Cadmium Hydride

Thomas D. Varberg1 and Robert J. Le Roy2 1Department of Chemistry, Macalester College, St. Paul, MN 55105 USA 2Guelph-Waterloo Centre for Graduate Work in Chemistry and Biochemistry, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada

New measurements of far-infrared transitions within the υ = 1 levels of the X2Σ+ state of six different isotopomers of CdH and CdD are combined with previous mid-infrared [1,2] and far-infrared [3] data in a combined-isotopomer analysis which yields improved low-order rotational constants, spin–rotation constants and Born–Oppenheimer breakdown (BOB) parameters for this system. Recent work by one of us [3] had reported the measurement and analysis of far-infrared transitions within the υ = 0 level of twelve isotopomers of CdH and

CdD, but the combined-isotopomer analysis reported there found that the hydride and deuteride data appeared to be incompatible unless separate Cd-atom BOB parameters were introduced for the inertial rotation constants of CdH and CdD, and BOB parameters introduced for the spin–rotation constants. The present work shows that taking account of the υ-dependence of the mechanical rotational parameters for υ = 0 isotopomers implied by the reduced-mass-scaling of vibrational quantum numbers allows the far-infrared data to be accounted for without invoking these two assumptions.

[1] R.-D. Urban, U. Magg, H. Birk and H. Jones, J. Chem. Phys. 92, 12–21 (1990). [2] H. Birk, R.-D. Urban, P. Polomsky and H. Jones, J. Chem. Phys. 94, 5435–5442 (1991). [3] T. D. Varberg and J. C. Roberts, J. Mol. Spectrosc. 223, 1-8 (2004).

151

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Doppler-free Two-photon Excitation Spectroscopy and the Zeeman Effect 1 1 1 1 of the 10 140 Band of the S1 B2u←S0 A1g Transition of Benzene-d6

Dae Youl Baek1, Jinguo Wang1, Atsushi Doi1, Shunji Kasahara1, Masaaki Baba2 and Hajime Katô1 1Molecular Photoscience Research Center, Kobe University, Nada-ku, Kobe, Japan 2Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan

1 1 1 1 The 10 140 band of the S1 B2u ← S0 A1g transition in the benzene-d6 molecule had been reported that the rotational structure was not able to analyze and only the J=K lines were seemed to be in the neighborhood of the expected positions [1]. We have measured a

1 1 Doppler-free two-photon excitation spectrum and the Zeeman effect of the 10 140 band of

C6D6 with counter-propagating light beams of identical wavelength within an external cavity.

The spectrum in the range of 40734.0 - 40723.7 cm-1 were recorded. The spectral lines were found to be strongly perturbed, but a number of perturbed and perturbing lines could be identified from the regularity of the energy shifts. Rotationally resolved 616 lines of the

Q(K)Q(J) transitions of J=0-54, K=0-54 were assigned. Zeeman effects and accurate frequency marks were useful to assign the spectral lines. No perturbation originating from an interaction with a triplet state was observed. Background lines which were observed with weak intensity and could not be assigned were found to be a singlet state from the Zeeman spectra. The Zeeman splittings in lines of a given J were observed to increase proportionally to K2, and the ones of the K=J levels were observed to increase proportionally to J. These are consistent with a conclusion that the Zeeman splitting is originating from mixing of the S1

1 1 B2u and S2 B1u states by the J-L coupling [2].

[1] H. Sieber, E. Riedle, and H. J. Neusser, J. Chem. Phys. 89, 4620 (1988). [2] A. Doi, S. Kasahara, H. Katô, and M. Baba, J. Chem. Phys. 120, 6439 (2004).

152

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Electronic Spectra of Molecules with Two C3v Internal Rotors: 1 1 Torsional Analysis of the A A u– X A g LIF Spectrum of Biacetyl

Cheng-Liang Huang1, Chen- Lin Liu2, Chi-Kung Ni2, and Jon T. Hougen3

1Department of Applied Chemistry, National Chiayi University, Chiayi, Taiwan 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, P.O. Box 23-166, Taiwan 3Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8441USA

1 1 The laser-induced fluorescence excitation spectrum of the A Au (S1) - X Ag (S0) -1 transition of biacetyl (CH3-C(=O)-C(=O)-CH3) in the region from 22 182 to 28 000 cm shows a complicated absorption line spectrum, arising from a long progression in the torsional vibrations of the two equivalent trans methyl tops in this molecule. In this poster we present a quantitative and qualitative description of this spectrum. A quantitative understanding was obtained by first numerically calculating these two-top torsional energy levels using a kinetic and potential energy formalism and preliminary constants from the literature.a The molecular constants in this two-top model were then refined by carrying out a least-squares fit to vibrational band origins in the region from 0 to 300 cm-1 above the onset of the A-X absorption. These band origins were obtained from high-resolution spectra recently measured using a near Fourier transform-limited high resolution laser system at IAMS. A qualitative understanding of the resulting numerical energy level pattern was obtained by applying local mode ideas and G36 permutation-inversion group symmetry species to the two equivalent methyl-rotor torsions. It was found that levels with one quantum of torsional excitation are best described by a normal mode formulation, but that levels with more than one quantum of torsional excitation are better described by a local mode formulation. Even though good agreement has been obtained for levels with up to four quanta of torsional excitation, full confirmation of the present interpretation will require rotational analyses of some of the higher-energy bands. ______aM. L. Senent, D. C. Moule, Y. G. Smeyers, A. Toro-Labbé and F. J. Peqalver, J. Mol. Spectrosc. 164, 66-78 (1994).

153

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Rotationally Resolved Photoelectron Spectrum of NH2 and ND2: + 1 ~ + 3 Rovibrational Energy Level Structure of the ã A1 and X B1 States

1 2 1 Stefan Willitsch , John M. Dyke and Frédéric Merkt

1 Physical Chemistry, ETH Zürich, 8093 Z¨urich, Switzerland 2 Department of Chemistry, The University, Southampton SO17 1BJ, United Kingdom

Fully rotationally resolved pulsed-field-ionisation zero-kinetic-energy photoelectron

~ 2 + 1 spectra of NH2 and ND2 have been recorded in the vicinity of the X B1 → ã A1 photoelectron band between 99500 and 103500 cm-1. The spectrum is dominated by a strong

~ 2 + 1 band attributed to the X B1 (0, 0, 0) → ã A1 (0, 0, 0) transition. Weaker bands are assigned

~ + 3 to transitions to highly excited bending levels of the X B1 ground ionic state and to the first + symmetric stretching and bending levels of the ã state. The r0 structure of the amidogen ion in its lowest singlet (ã+) electronic state was derived from an analysis of the rotational structure (r0(N-H) = 1.051(3) Å, α0(HNH) = 109.2(3) Å). A model describing the rotational intensities in the photoelectron spectra of asymmetric top molecules [1] was used to demonstrate that photoionisation occurs out of a p orbital on the central N-atom and that the photoelectron partial wave composition is dominated by the d component. No perturbations in + the rotational structure of the lowest levels of the ã state resulting from the Renner-Teller

~ + ~ + coupling to theb state could be detected. The adiabatic ionisation energy of the X → ã

-1 transition was determined to be 100305.8±0.8 cm (12.43633±0.00010 eV) in NH2 and

-1 100366.2±0.9 cm (12.44382±0.00011 eV) in ND2.

~ + 3 First PFI-ZEKE photoelectron spectra of the quasilinear X B1 state using a twophoton ~ 2 excitation scheme via selected rovibronic levels of the A A1 state will also be presented.

[1] S. Willitsch, U. Hollenstein, and F. Merkt, J. Chem. Phys. 120, 1761 (2004)

154

C2-16

Isomers of CNO2: Infrared Absorption of ONCO in Solid Neon

Yu -Jong Wu1, Chun-Pang Chou1, and Yuan -Pern Lee1, 2 1Department of Chemistry, National Tsing Hua University, Hsingchu, Taiwan 30013 2Institute of Atomic and Molecular Sciences, Academic Sinica, Taipei, Taiwan 106

The reaction of CN with O2 is important in combustion of nitrogen-bearing fuel. Three 2 3 2 3 product channels have been reported: (1) CN ( Σ) + O2 ( Σg)→ NCO ( Σ) + O ( P), (2) CN 1 2 1 2 + O2 → CO ( Σ) + NO ( Π), and (3) CN + O2 → CO2( Σg) + N ( D). Mohammad et al. employed infrared emission spectroscopy [1] to measure branching ratio to determine a branching ratio 29% for channel (2). They suggested that the reaction proceeds via an energetically intermediate. To our knowledge, no intermediate of CNO2 has been experimentally observed. Benson and Francisco performed a high-level ab inito calculation to characterize the structure, spectra, and heat of the formation of ONCO radical [2]. Recently Qu et al. calculated the doublet NCO2 potential energy surface and located six isomers of CNO2 [3]. The matrix isolation technique is known for its superiority in trapping and preserving unstable species. Irradiation of a Ne matrix sample containing NO and CO with an ArF excimer laser at 193 nm yields ONCO radicals. New lines at 2045.1, and 968.0 cm-1 appear after photolysis; secondary photolysis at 308 nm diminishes these lines and produces NO and CO. These lines are assigned to C—O stretching and C—N stretching modes of ONCO, respectively, based on results of 13C-isotopic experiments and theoretical calculations. Theoretical calculations using density-functional theories (B3LYP and PW91PW91) predict four stable isomers of NCO2: ONCO, NCOO, NCO2, and CNOO, listed in increasing order of energy. Calculated vibrational wave numbers, IR intensities, and 13C-isotopic shifts for ONCO fit satisfactorily with experimental result. This new spectral identification of ONCO provides information for future investigations of its roles in atmospheric chemistry. This experiment also demonstrates that electronic excitation may assist in reactions that have high barriers on the ground electronic surface.

[1] F. Mohammad, V. R. Morris, W. H. Fink, and W. M. Jackson, J. Phys. Chem. 97, 11590 (1993). [2] B. D. Benson and J. S. Francisco, Chem. Phys. Lett. 233, 335 (1995). [3] Z. W. Qu, H. Zhu, Z. S. Li, X. K. Zang, and Q. Y. Zang, Chem. Phys. Lett. 353, 304 (2002).

155

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IR Spectroscopy of Ge(NO) and Ge(NO)2 Isolated in Solid Argon

Chun-Pang Chou1, Yu-Jong Wu1 and Yuan-Pern Lee1, 2 1Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan 30013 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106

Germanium is known as an important material in semiconductor industry. Nitridation of germanium surface forms germanium nitride film that has distinct properties with original material. By understanding the involvement of nitrogen impurity one might control the electric and other properties of semiconductor material. Hence, spectral characterization of species of germanium nitride is of fundamental interest. Laser-ablated Ge atoms react with NO before being deposited on a Ni-coated Cu target at 13K. IR absorption spectra are recorded in the range of 500－4000 cm-1 at a resolution of 0.5 cm-1. A XeCl laser at 308 nm and an ArF laser at 193 nm were empolyed for secondary photolysis. Mixtures of N16O/N18O and 14NO/15NO were used for mixed isotopic experiments. Two groups of new lines were observed upon deposition. Group A consists of one line at 1543.8 cm-1； it shifts to 1513.7 cm-1 and 1509.8 cm-1 upon 15N- and 18O- isotopic substitution. This line is assigned to the N=O stretching mode of GeNO based on results of isotopoic substitution and theoretical calculations. Theoretical calculations using the density-functional theory (B3LYP/aug-cc-pVTZ) predict optimized structure of linear GeNO with bond lengths of 1.75Å (Ge-N) and 1.20Å (N=O) . Group B consists of two new lines at 1428.8 cm-1 and 1645.5 cm-1. The line at 1428.8 cm-1 shifts to (1469.1 cm-1, 1457.7 cm-1) and (1460.3 cm-1, 1443.0 cm-1), respectively, upon 15N- and 18O- isotopic substitution, whereas the line at 1645.5 cm-1 shifts to (1631.5 cm-1, 1615.5 cm-1) and (1627.0 cm-1, 1603.9 cm-1) , respectively. The line at 1428.8 cm-1 is assigned to the N=O asym-stretching mode and the -1 line at 1645.5 cm is assigned to the N=O sym-stretching modes of Ge(NO)2. Theoretically predicted structure of Ge(NO)2 has C2V symmetry, with bond lengths of 1.93 Å (Ge-N), 1.17 Å (N=O) and angles ∠ NGeN=74.97 °, ∠ GeNO=137.27 °. Calculated vibrational wave

15 18 numbers, IR intensities, N- and O- isotopic shifts for both GeNO and Ge(NO)2 fit satisfactorily with our experimental results.

156

C2-18

Dissociative Recombination of Hydrocarbon Ions

A. Ehlerding1, W. Geppert1, V. Zhaunerchyk1, F. Hellberg1, R. Thomas1, S. T. Arnold2, A. A. Viggiano2, J. Semaniak3, F. Österdahl4, M. af Ugglas5, M. Larsson1 1 Department of Physics, Stockholm University, AlbaNova, 106 91 Stockholm, Sweden 2 AFRL, Space Vehicles Directorate, 29 Randolph Rd, Hanscom AFB, MA 01731, USA 3 Swietokrzyska Academy,25-406 Kielce, Poland 4 Department of Physics, Royal Institute of Technology, AlbaNova, 106 91 Stockholm, Sweden 5 Manne Siegbahn Laboratory, Stockholm University, 104 05 Stockholm, Sweden

Dissociative recombination (DR) is the process where the molecular ion stabilizes from the capture of an electron by dissociation via a repulsive excited state in the neutral molecule. This process plays a significant role as the main neutralization process in different plasma processes, for example plasma enhanced combustion [1]. Since simulations have shown that the formation of radicals in the DR of the hydrocarbon fuel have a large influence on the efficiency of the reactor, the product distribution of these ions are being investigated in a systematic study at the CRYRING heavy ion storage ring, Stockholm, Sweden. Previously reported results from this study concerned the DR cross section and + + + + + chemical branching fractions of C2H [2], C2H2 [3], C2H3 [4], C2H4 [2] and C3H7 [5]. This + + + + has now been further extended to C2D5 , C3H4 , C3D7 and C4D9 . One of the most interesting features in these results is that the ions containing only two carbon atoms have a very high probability of multiple hydrogen detachment, whereas it is much smaller for the larger hydrocarbon ions. The breakup of the carbon-carbon bond on the other hand seems to be more + favorable for the larger species, C3H4 being an exception.

[1] S. Williams, et al., JANNAF 25th Air-breathing Propulsion Meeting, Monteray, p205 (2000) [2] A. Ehlerding, et al., PCCP, 6, 949 (2004) [3] A. M. Derkatch, et al., J. Phys. B, 32, 3391 (1999) [4] S. Kalhori, et al., Astr. Astrophys., 391, 1159 (2002) [5] A. Ehlerding, et al., J. Phys. Chem. A, 107, 2179 (2003)

157 C2-19

The Effect of Bonding on the Fragmentation of Small Systems

R. D. Thomas1, A. Ehlerding1, W. Geppert1, F. Hellberg1, M. Larsson1, S. Rosén1, V. Zhaunerchyk1, E. Bahati2, M. E. Bannister2, C. R. Vane2, A. Petrignani3, W. J. van der Zande3,4, P. Andersson5, and J. B. C. Pettersson5.

1Department of Physics, Albanova University Centre, Stockholm University, S106 91 Stockholm, Sweden 2Physics Division, Oak Ridge National Laboratory, P.O.Box 2008, Oak Ridge, TN 37831-6377 3FOM Instituut AMOLF, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands 4Department of Physics, University of Nijmegen, 6525 ED Nijmegen, The Netherlands 5Department of Chemistry, Atmospheric Science, Göteborg University, SE-412 96 Göteborg, Sweden

In several recent dissociative recombination (DR) experiments, the observed DR products depend heavily on the structure of the molecular ion, specifically the type of bonds which determines the structure. For examples, the dominant product channel observed in the DR of

+ + + + N2O2 and D5 suggests that these ions have the form NO .NO and D3 .D2, respectively, whilst

+ + the D5O2 system is best represented by D .(D2O)2 [1]. We compare and contrast these

+ observations by investigating the DR of one of the simplest such systems, Li .H2. This will provide us with an excellent opportunity for understanding the role played by the molecular bonds and charge center in the DR process.

[1] M. B. Någård et al. J. Chem. Phys., 117, 5264 (2002)

158 C2-20

Dynamics and Spectroscopy of Threshold Photoion-Pair Formation

Qichi Hu and John Hepburn Department of Chemistry University of British Columbia Vancouver, BC, Canada

In recent years we have exploited a new form of Rydberg state based on charge separation [1] in very weakly bound vibrationally excited ion-pair states to make precise measurements of ion-pair dissociation thresholds. In this talk I shall discuss the results of some recent work, where we have focused on the dynamics of formation of these ion-pair Rydberg states and ion-pair photofragments, which typically involves a form of dissociative recombination of a Rydberg electron with an ion core. We have consistently found that the energy dependence of the cross section for photoion-pair production in small molecules shows mostly sharp resonances with little or no continuum contribution, supporting the model of dissociative recombination of conventional Rydberg states. In some cases, we have been able to do some tentative assignments of the Rydberg states responsible.

I shall focus on two simple systems: HCl/DCl and HF/DF, where the dynamics are driven almost exclusively by Rydberg state decay. HF/DF is particularly interesting, as the ion-pair dissociation threshold and the molecular ionization threshold are nearly isoenergetic, and the cross-section for photoionization and photoion-pair production are comparable at threshold.

[1] J.D.D. Martin and J.W. Hepburn, Phys. Rev. Lett. 79, 3154 (1997)

159 C2-21

One- and two-photon excitation vibronic spectra of 2-methylallyl radical at 4.6–5.6 eV

Chun-Cing Chen1, Hsing-Chen Wu2, Chien-Ming Tseng2, Yi-Han Yang2, and Yit-Tsong Chen1,2 1Institute of Atomic and Molecular Sciences, Academia Sinica 2Department of Chemistry, National Taiwan University, and

Vibronically excited 2-methylallyl radical (CH2C(CH3)CH2) at 4.6–5.6 eV has been studied by 1+1 and 2+2 resonance-enhanced multiphoton ionization (REMPI) spectroscopy. [1] The 2-methylallyl radicals were produced by the flash pyrolysis (>1000°C ) of 3-bromo-2-methylpropene in a supersonic-jet expansion. The 2+2 REMPI spectrum of 2-methylallyl radical at 38000–40500 cm-1 is identified as ~ 2 ~ 2 B (1 A1 ) ← X (1 A 2 ) transition, i.e. the excitation of a non-bonding electron to the 3s Rydberg state ( 3s ← n ). Seven lowest-lying electronic states with excitation energy below 6 eV have been calculated in an MRCI level. Two new electronic bands have been observed at 38500–41000 cm-1 by 1+1 REMPI spectroscopy and ~ 2 ~ 2 ~ 2 assigned to C (1 B2 ) ← X (1 A 2 ) and E (2 A 2 ) ← ~ 2 X (1 A 2 ) . Much broader 1+1 REMPI signals at 41000-43500 cm-1 with HWHM of 80 cm-1 for each ~ 2 ~ 2 vibronic band could be due to D (2 B2 ) ← X (1 A2 ) ~ 2 ~ 2 and/or F (3 B2 ) ← X (1 A 2 ) via an intensity borrowing ~ 2 ~ 2 from C (1 B2 ) ← X (1 A 2 ) . Taking the computed (a) The 2+2 REMPI spectrum of geometries and vibrations of the ground- and excited- 2-methylallyl radical. (b) Calculated spectral intensities (FCFs only) for the electronic states, Franck-Condon factors (FCFs) have ~ 2 vibronic bands of B (1 A1 ) ← been calculated. Combining the FCFs with calculated ~ 2 X (1 A2 ) . (c) The 1+1 REMPI excitation energies and oscillator strengths of the six spectrum of 2-methylallyl radical. electronic states at 4–6 eV, predicted spectral patterns (d)-(e) Calculated spectral intensities have been used to assist spectroscopic analysis for the (including the electronic oscillator strength and FCFs) for the vibronic observed vibronic spectra of 2-methylallyl radical. ~ 2 ~ 2 bands of E (2 A2 ) ← X (1 A2 ) and ~ 2 ~ 2 C (1 B2 ) ← X (1 A 2 ) , respectively. [1] Chun-Cing Chen, Hsing-Chen Wu, Chien-Ming Tseng, Yi-Han Yang, and Yit-Tsong Chen Journal of Chemical Physics, 119, 241-250 (2003).

160

Index of Author (Presented work is indicated by *)

161 List of Participants

Abrash, Samuel A. Akimoto, Hajime Department of Chemistry Atmospheric Composition Research University of Richmond Program, Richmond, VA 23173 Frontier Research System for Global USA Change Tel: +1-804-289-8248 Yokohama, 236-0001 Fax: +1-804-287-1897 Japan [email protected] Tel: +81-45-778-5710 Fax: +81-45-778-5496 [email protected]

Alam, Mohammad Shahdo Althorpe, Stuart C. Department of Chemistry Department of Chemistry National Tsing Hua University University of Exeter Hsinchu, 30013 Exeter, EX4 4QD Taiwan UK Tel: +886-3-5714687 Tel: +44-1392-263473 Fax: +886-3-5722892 Fax: +44-1392-263434 [email protected] [email protected]

Aoiz, Francisco Javier Bahou, Mohammed Departamento de Quimica Fisica I Department of Chemistry Universidad Complutense de Madrid National Tsing Hua University Madrid, 28040 101, Sec. 2, Kuang Fu Road Spain Hsinchu, 30013 Tel: +34-913-944126 Taiwan Fax: +34-913-944135 Tel: +886-3-5715131-3421 [email protected] Fax: +886-3-5722892 [email protected]

Balfour, Rosemary Balfour, Walter J. Department of Chemistry Department of Chemistry University of Victoria University of Victoria Victoria BC, V8W 3P6 Victoria BC, V8W 3P6 Canada Canada Tel: +1-250-721-7168 Tel: +1-250-721-7168 Fax: +1-250-721-7147 Fax: +1-250-721-7147 [email protected] [email protected]

34 Bernath, Peter F. Bondybey, Vladimir E. Department of Chemistry Institute fur Physicalishe Chemie University of Waterloo Technische Universitat Munchen 200 University Avenue West Lichtebergstr. 4 Waterloo, Ontario, N2L 3G1 Garching, D-8574 Canada Germany Tel: +1-519-888-4814 Tel: +49-89-2891-3421 Fax: +1-519-746-0435 Fax: +49-89-2891-3416 [email protected] [email protected]

Brouard, Mark Brown, John M. The Physical and Theoretical Chemistry The Physical and Theoretical Chemistry Laboratory Laboratory, Department of Chemistry University of Oxford, South Parks Road University of Oxford, South Parks Road Oxford, OX1 3QZ Oxford, OX1 3QZ UK UK Tel: +44-1865-275410 Tel: +44-1865-275457 Fax: +44-1865-275410 Fax: +44-1865-275410 [email protected] [email protected]

Butler, Laurie J. Butler, Lynne M. James Franck Institute James Franck Institute 5640 S. Ellis Ave 5640 S. Ellis Ave Chicago, IL 60637 Chicago, IL 60637 USA USA Tel: +1-773-702-7206 Tel: +1-773-702-7206 Fax: + Fax: + [email protected] [email protected]

Casavecchia, Piergiorgio Castillo, Jesus F. Dipartimento di Chimica Departamento de Quimica Fisica I Universita di Perugia Universidad Complutense de Madrid Perugia, 06123 Madrid, 28040 Italy Spain Tel: +39-0755855514 Tel: +34-913-944-126 Fax: +39-0755855606 Fax: +34-913-944-135 [email protected] [email protected]

Chang, Ying-de Chang, Chih-Wei Institute of Atomic and Molecular Science, Department of Applied Chemistry Academia Sinica National Chiao Tung University P. O. Box 23-166 1001, Ta-Hsueh Rd. Taipei, 106 Hsinchu, 30010 Taiwan Taiwan Tel: +886-2-2366-8250 Tel: +886-3-5712121-56570 Fax: +886-2362-0200 Fax: +886-3-5723764 [email protected] [email protected]

35 Chang, Bor-Chen Chang, Wei-Zhong Department of Chemistry Department of Chemistry National Central University National Central University 300 Jung-Da Road 300 Jung-Da Road Chung Li, 32054 Chung Li, 32054 Taiwan Taiwan Tel: +886-3-4227151x5908 Tel: +886-3-4227151x5918 Fax: +886-3-4227664 Fax: +886-3-4227664 [email protected] [email protected]

Chang, Chushuan Chang, Huan-Cheng Institute of Atomic and Molecular Sciences, Institute of Atomic and Molecular Sciences, Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8257 Tel: +886-2-2366-8260 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Chen, Ming-Wei Chen, Chun-Cing Department of Chemistry Institute of Atomic and Molecular Science, National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5643335 Taiwan Fax: +886-3-5717553 Tel: +886-2-2366-8250 [email protected] Fax: +886-2362-0200 [email protected]

Chen, Hsueh-Ying Chen, Chia-Yi Department of Chemistry Department of Chemistry National Tsing Hua University National Central University Hsinchu, 30013 300 Jung-Da Road Taiwan Chung Li, 32054 Tel: +886-3-5715131-3423 Taiwan Fax: + Tel: +886-3-4227151-5918 [email protected] Fax: +886-3-4227664 [email protected]

Chen, Kuo-Mei Chen, Stella L. Department of Chemistry Department of Chemistry and Biochemistry, National Sun Yat-sen University University of Colorado Kaohsiung, 804 Boulder, CO 80309 Taiwan USA Tel: +886-7-525-3911 Tel: +1-303-492-5406 Fax: +886-7-525-3912 Fax: +1-303-492-5894 [email protected] [email protected]

36 Chen, Yang Chen, Kan-Sen Dept. of Chem. Phys. Institute of Atomic and Molecular Sciences, University of Science and Technology of Academia Sinica China P. O. Box 23-166 Hefei, 230026 Taipei, 106 China Taiwan Tel: +86-551-360-6619 Tel: +886-2-2366-8217 Fax: +86-551-360-7084 Fax: +886-2-2362-0200 [email protected] [email protected]

Chen, I-Chia Chen, Yit-Tsong Department of Chemistry Department of Chemistry National Tsing Hua University National Taiwan University Hsinchu, 30013 No. 1, Sec. 4, Roosevelt Road Taiwan Taipei, 106 Tel: +886-3-5715131-3339 Taiwan Fax: +886-3-5721614 Tel: +886-2-366-8238 [email protected] Fax: +886-2-2362-0200 [email protected]

Chen, Hui-Fen Chen, Wei-Kan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-3-5715131-3423 Fax: +886-3-5722892 Fax: + [email protected] [email protected]

Cheng, Mu-Jeng Cheng, Po-Yuan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3390 Tel: +886-3-573-7816 Fax: +886-3-5711082 Fax: + [email protected] [email protected]

Cheng, Chao-Han Chiang, Su-Yu Department of Chemistry National Synchrotron Radiation Research National Tsing Hua University Center Hsinchu, 30013 101, Hsin-Ann Rd. Taiwan Science-Based Industrial Park Tel: +886-3-5715131-3425 Hsinchu, 30077 Fax: +886-3-5721614 Taiwan [email protected] Tel: +886-3-5780281-7315 Fax: +886-3-5783813 [email protected]

37 Ching, Dauw-Chung Choi, Jong-Ho Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica Korea University P. O. Box 23-166 Anam-dong, Sungbuk-ku Taipei, 106 Seoul, 136-701 Taiwan Korea Tel: +886-2-2912-2437 Tel: +82-2-3290-3135 Fax: +886-2-2362-0200 Fax: +82-2-3290-3121 [email protected] [email protected]

Choi, Woosuk Chou, Chun Pang Department of Chemistry Department of Chemistry Korea University National Tsing Hua University Anam-dong, Sungbuk-ku Hsinchu, 30013 Seoul, 136-701 Taiwan Korea Tel: +886-3-5715131-3346 Tel: +82-2-3290-3135 Fax: +886-3-5722892 Fax: +82-2-3290-3121 [email protected] [email protected]

Chou, Po Han Chou, Yung-Ching Department of Chemistry Institute of Atomic and Molecular Sciences, National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5715131-3346 Taiwan Fax: +886-3-5722892 Tel: + [email protected] Fax: + [email protected]

Chou, Sheng Lung Chu, San-Yan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-3-5715131-3390 Fax: +886-3-5722892 Fax: +886-3-5711082 [email protected] [email protected]

Chuang, Su-Ching Chung, Chao-Yu Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3345 Tel: +886-3-5715131-5407 Fax: +886-3-5722892 Fax: +886-3-5722892 [email protected] [email protected]

38 Colin, Reginald Continetti, Robert E. Laboratoire de Chimie Quantique et Department of Chemistry and Biochemistry Photophysique, CP 160/9 Univ. California, San Diego Université Libre de Bruxelles 9500 Gilman Drive 50,av. F. D. Roosevelt La Jolla, CA 92093-0340 1050 Brussels USA Belgium Tel: +1-858-534-5559 Tel: +32-2-650-2420 Fax: +1-858-534-7244 Fax: +32-2-650-4232 [email protected] [email protected]

Curl, Jonel W. Curl, Robert F. Chemistry Department MS-60 Chemistry Department MS-60 Rice University Rice University Houston, TX 77005 Houston, TX 77005 USA USA Tel: +1-713-348-4816 Tel: +1-713-348-4816 Fax: +1-713-348-5155 Fax: +1-713-348-5155 [email protected] [email protected]

Dagdigian, Paul J. Dai, Dongxu Department of Chemistry, Remsen Hall Dalian Institute of Chemical Physics Johns Hopkins University Chinese Academy of Sciences 3400 N. Charles Street 457 Zhongshan Road Baltimore, MD 21218 Dalian, 116023 USA China Tel: +1-410-516-7438 Tel: +86-411-84379360 Fax: +1-410-516-8420 Fax: +86-411-84675584 [email protected] [email protected]

Diau, Eric Wei-Guang Dyakov, YuRi Department of Applied Chemistry Institute of Atomic and Molecular Sciences, National Chiao Tung University Academia Sinica 1001, Ta-Hsueh Rd. P. O. Box 23-166 Hsinchu, 30010 Taipei, 106 Taiwan Taiwan Tel: +886-3-5131524 Tel: +886-2-2366-8272 Fax: +886-3-5723764 Fax: +886-2-2362-0200 [email protected] [email protected]

Ehlerding, Anneli Endo, Yasuki Department of Physics Department of Basic Science Stockholm University The University of Tokyo Alba Nova University Center Komaba 3-8-1, Meguro Stockholm, SE106 91 Tokyo, 153-8902 Sweden Japan Tel: +46-8-55378648 Tel: +81-3-5454-6748 Fax: +46-8-55378601 Fax: +81-3-5454-6721 [email protected] [email protected]

39 Fang, Yung-Sheng Fujii, Asuka National Synchrotron Radiation Research Department of Chemistry Center Graduate School of Science 101, Hsin-Ann Road Tohoku University Science-Based Industrial Park Sendai, 980-8578 Hsinchu, 30077 Japan Taiwan Tel: +81-22-217-6573 Tel: +886-3-5780281 Fax: +81-22-217-6785 Fax: +886-3-5783813 [email protected] [email protected]

Fujimura, Yo Geppert, Wolf D. Department of Chemistry Department of Molecular Physics Graduate School of Science Alba Nova, University of Stockholm, Kyoto University Roslagstullbacken 21 Kitashirakawa-Oiwakecho, Sakyo-ku Stockholm, S-10691 Kyoto, 606-8502 Sweden Japan Tel: +46-8-5537-8649 Tel: +81-75-753-3972 Fax: +46-8-5537-8601 Fax: +81-75-753-3974 [email protected] [email protected]

Graham, Hsueh Mei Graham, William R. M. Department of Physics and Astronomy Department of Physics and Astronomy Box 298840, TCU Box 298840, TCU Fort Worth, TX 76129 Fort Worth, TX 76129 USA USA Tel: +1-817-257-6383 Tel: +1-817-257-6383 Fax: +1-817-257-7740 Fax: +1-817-257-7740 [email protected] [email protected]

Guss, Joseph S. Halberstadt, Nadine School of Chemistry Laboratorire de Physique University of Sydney Quantique/IRSAMC, Université Paul Sabatier Sydney, NSW 2006 118 route de Narbonne Australia Toulouse, 31062 Tel: +61-2-9351-4424 France Fax: +61-2-9351-3329 Tel: +33-5-6155-6488 [email protected] Fax: +33-5-6155-6065 [email protected]

Han, Ke-Li Han, Huei-Lin Dalian Institute of Chemical Physics Department of Chemistry Chinese Academy of Sciences National Tsing Hua University P. O. Box 110-11 Hsinchu, 30013 457 Zhongshan Road Taiwan Dalian, 116023 Tel: +886-3-5715131-3346 China Fax: +886-3-5722892 Tel: +86-411-843-79293 [email protected] Fax: +86-411-846-75584 [email protected]

40 Haung, Jackson Heaven, Michael C. Department of Chemistry Department of Chemistry National Tsing Hua University Emory University Hsinchu, 30013 1515 Dickey Drive Taiwan Atlanta, GA 30322 Tel: +886-3-5715131-3423 USA Fax: + Tel: +1-404-727-6617 [email protected] Fax: +1-404-727-6586 [email protected]

Hepburn, John W. Hirota, Satoko Faculty of Science The Graduate University for Advanced The University of British Columbia, Studies #1505-6270 University Blvd. Hayama, Kanagawa 240-0193 Vancouver, BC V6T 1Z4 Japan Canada Tel: +81-468-58-1500 Tel: +1-604-822-0220 Fax: +81-468-58-1542 Fax: +1-604-822-0677 [email protected] [email protected]

Hirota, Eizi Ho, Jia-Jen The Graduate University for Advanced Department of Chemistry Studies National Taiwan Normal University Hayama, Kanagawa 240-0193 88, Sec. 4, Ting-Chow Rd. Japan Taipei, 116 Tel: +81-468-58-1500 Taiwan Fax: +81-468-58-1542 Tel: +886-2-2930-9085 [email protected] Fax: +886-2-2932-4249 [email protected]

Ho, Jr-Wei Ho, Tong-Ing Department of Chemistry Department of Chemistry National Tsing Hua University National Taiwan University Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3423 Tel: +886-2-23691801 Fax: + Fax: +886-2-23636359 [email protected] [email protected]

Honma, Kenji Hougen, Jon T. Department of Material Science Optical Technology Division, NIST Himeji Institute of Technology Gaithersburg, MD 20899-8441 3-2-1 Kohto, Kamigori USA Hyogo, 678-1297 Tel: +1-301-975-2379 Japan Fax: +1-301-975-2950 Tel: +81-791-58-0167 [email protected] Fax: +81-791-58-0132 [email protected]

41 Hsu, Hsu-Chen Hsu, Yen-Chu Institute of Atomic and Molecular Sciences, Institute of Atomic and Molecular Sciences, Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8268 Tel: +886-2-2366-8281 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Hsu, Hui-Ju Hu, Shuiming Department of Chemistry Dept. Chem. Physics National Central University Univ. of Science and Technology of China 300 Jung-Da Road Jinzhai Road, 96# Chung Li, 32054 Hefei, 230026 Taiwan China Tel: +886-3-4227151x5918 Tel: +86-551-3607460 Fax: +886-3-4227664 Fax: +86-551-3602969 [email protected] [email protected]

Hu, Helen YiaoYing Huang, Hong-Yi Department of Chemistry Institute of Atomic and Molecular Science, The University of York Academia Sinica York, YO10 5DD P. O. Box 23-166 UK Taipei, 106 Tel: +44-1904-434526 Taiwan Fax: +44-1904-434527 Tel: +886-2-2366-8289 [email protected] Fax: +886-2362-0200 [email protected]

Huang, Cheng-Liang Hung, Andy Applied Chemistry Department Department of Chemistry Chiayi University National Tsing Hua University 300, University Road Hsinchu, 30013 Chiayi, 600 Taiwan Taiwan Tel: +886-3-5715131-3423 Tel: +886-5-2717879 Fax: + Fax: +886-5-2717901 [email protected] [email protected]

Hutson, Jeremy M. Ishikawa, Haruki Department of Chemistry Department of Chemistry University of Durham Graduate School of Science Durham, DH1 3LE Tohoku University UK Aramaki-Aoba, Aoba-ku Tel: +44-191-334-2147 Sendai, 980-8578 Fax: +44-191-384-4737 Japan [email protected] Tel: +81-22-217-6573 Fax: +81-22-217-6785 [email protected]

42 Jacox, Marilyn E. Jensen, Per Mail Stop 8441 Faculty of Mathematics and Natural Optical Technology Division Sciences, Department of Chemistry National Institute of Standards and Bergische Universität Wuppertal Technology Wuppertal, D-42097 Gaithersburg, MD 20899-8441 Germany USA Tel: +49-202-439-2468 Tel: +1-301-975-2547 Fax: +49-202-439-2509 Fax: +1-301-869-5700 [email protected] [email protected]

Jones, Norma Jones, William E. Saint Mary's University Saint Mary's University Burke Building, Suite 110 Burke Building, Suite 110 Halifax NS, B3H 3C3 Halifax NS, B3H 3C3 Canada Canada Tel: +1-902-496-8169 Tel: +1-902-496-8169 Fax: +1-902-496-8772 Fax: +1-902-496-8772 [email protected] [email protected]

Kable, Scott H. Kanamori, Hideto School of Chemistry Department of Physics University of Sydney Tokyo Institute of Technology Sydney, NSW 2006 2-12-1 Ohokayama, Muguro-ku Australia Tokyo, 152-8551 Tel: +61-2-9351-2756 Japan Fax: +61-2-9351-3329 Tel: +81-3-5734-2615 [email protected] Fax: +81-3-5734-2751 [email protected]

Kato, Hajime Katoh, Kaoru Molecular Photoscience Research Centre Department of Basic Science Kobe University Graduate School of Arts and Sciences Rokkodai-cho 1-1, Nada-ku The University of Tokyo Kobe, 657-8501 Komaba 3-8-1, Meguro-ku Japan Tokyo, 153-8902 Tel: +81-78-803-5671 Japan Fax: +81-78-803-5678 Tel: +81-3-5454-6766 [email protected] Fax: +81-3-5454-6721 [email protected]

Kobayashi, Ayana Kobayashi, Tsuyoshi Graduate School of Sci. and Engine. Graduate School of Sci. and Engine. Tokyo Inst. Tech, Tokyo, Japan Tokyo Inst. Tech, Tokyo, Japan 2-12-1 Ohokayama, Muguro-ku 2-12-1 Ohokayama, Muguro-ku Tokyo, 152-8501 Tokyo, 152-8501 Japan Japan Tel: +81-3-5734-2704 Tel: +81-3-5734-2704 Fax: +81-3-5734-2751 Fax: +81-3-5734-2751 [email protected] [email protected]

43 Kobayashi, Kaori Kou, Che-lun Graduate School of Sci. and Engine. Department of Physics Tokyo Inst. Tech, Tokyo, Japan National Central University 2-12-1 Ohokayama, Muguro-ku 300, Jung Da Road Tokyo, 152-8501 Chung Li, 32054 Japan Taiwan Tel: +81-3-5734-2704 Tel: +886-3-4227151-5310 Fax: +81-3-5734-2751 Fax: + [email protected] [email protected]

Kumae, Takashi Lai, Ta-Jen Div. of Health Promotion & Exercise Department of Chemistry Natl. Inst. of Health Nutrition National Tsing Hua University 1-23-1 Toyama, Shinjuku-ku Hsinchu, 30013 Tokyo, 162-8636 Taiwan Japan Tel: +886-3-5715131-3423 Tel: +81-3-3203-8061 Fax: + Fax: +81-3-3203-1731 [email protected] [email protected]

Larsson, Mats Lee, Yin-Yu Department of Physics National Synchrotron Radiation Research Stockholm University Center AlbaNova 101, Hsin-Ann Road Stockholm, SE-10691 Science-Based Industrial Park Sweden Hsinchu, 30077 Tel: +46-8-5537-8647 Taiwan Fax: +46-8-5537-8601 Tel: +886-3-5780281-7114 [email protected] Fax: +886-3-5783813 [email protected]

Lee, Sheng-Jui Lee, Yuan-Pern Department of Chemistry Department of Applied Chemistry National Tsing Hua University National Chiao Tung University Hsinchu, 300 Hsinchu, 30010 Taiwan Taiwan Tel: +886-3-5715131-3427 Tel: +886-3-5715131-3345 Fax: +886-3-5721614 Fax: +886-3-5722892 [email protected] [email protected]

Lee, Shih-Huang Lee, Y. T. National Synchrotron Radiation Research Institute of Atomic and Molecular Sciences, Center Academia Sinica 101, Hsin-Ann Road P. O. Box 23-166 Science-Based Industrial Park Taipei, 106 Hsinchu, 30077 Taiwan Taiwan Tel: +886-2-2366-8200 Tel: +886-3-5780281 Fax: +886-2-2785-3852 Fax: +886-3-5783813 [email protected] [email protected]

44 Leone, Stephen R. Lester, Marsha I. University of California and Lawrence Department of Chemistry Berkeley National Laboratory University of Pennsylvania Department of Chemistry 231 S. 34th Street 209 Gilman Hall Philadelphia, PA 19104-4640 Berkeley, CA 94720-1460 USA USA Tel: +1-215-898-4640 Tel: +1-510-643-5467 Fax: +1-215-573-2112 Fax: +1-510-642-6262 [email protected] [email protected]

Li, Zhi-Ru Liang, Chi-Wei Institute of Theoretical Chemistry Institute of Atomic and Molecular Sciences Jilin University Academia Sinica Changchun, 130023 P. O. Box 23-166 China Taipei, 106 Tel: +86-431-8498964 Taiwan Fax: +86-431-8945942 Tel: +886-2-2246-6016 [email protected] Fax: +886-2-2362-0200 [email protected]

Lin, Ming Chang Lin, Min-Fu Department of Chemistry Institute of Atomic and Molecular Sciences Emory University Academia Sinica 1515 Dickey Drive P. O. Box 23-166 Atlanta, Georgia 30322 Taipei, 106 USA Taiwan Tel: +1-404-727-2825 Tel: +886-2-2366-8268 Fax: +1-404-727-6586 Fax: +886-2-2362-0200 [email protected] [email protected]

Lin, Jung-Lee Lin, I-Feng IAMS, Academia Sinica National Synchrotron Radiation Research P. O. Box 23-166 Center Taipei, 106 101, Hsin-Ann Road Taiwan Science-Based Industrial Park Tel: +886-2-2366-8222 Hsinchu, 30077 Fax: +886-2-2362-0200 Taiwan [email protected] Tel: +886-3-5780281 Fax: +886-3-5783805 [email protected]

Lin, Qiong Lin, King-Chuen Physical Chemistry Lab., ETH Honggerberg, Institute of Atomic and Molecular Sciences HCI E209 Academia Sinica Zurich, CH-8093 P. O. Box 23-166 Switzerland Taipei, 106 Tel: +41-1633-4391 Taiwan Fax: +41-1632-1021 Tel: +886-2-2369-0152x101 [email protected] Fax: +886-2-2362-0200 [email protected]

45 Lin, Sheng Hsien Lin, Jim J. Institute of Atomic and Molecular Sciences Institute of Atomic and Molecular Sciences Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8203 Tel: +886-2-2366-8258 Fax: +886-2-2362-4925 Fax: +886-2-2362-0200 [email protected] [email protected]

Lineberger, William Carl Liske, Christiane JILA, 440 UCB Department of Chemistry University of Colorado University of Basel Boulder, CO 80309-0440 Klingelbergstrasse 80 U. S. A. Basel, CH-4056 Tel: +1-303-492-7834 Switzerland Fax: +1-303-492-8994 Tel: +41-612673826 [email protected] Fax: +41-612673855 [email protected]

Liu, Chen-Lin Liu, Suet-Yi Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-2-2366-8268 Fax: +886-3-5722892 Fax: +886-2-2362-0200 [email protected] [email protected]

Liu, Shilin Liu, Tsui-Yu Department of Chemical Physics Department of Chemistry University of Science & Technology of China National Tsing Hua University Hefei, 230026 Hsinchu, 30013 China Taiwan Tel: +86-551-3602323 Tel: +886-3-5715131-3339 Fax: +86-551-3607084 Fax: +886-3-5721614 [email protected] [email protected]

Liu, Kopin Liu, Ching-Ping Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3420 Tel: +886-2-2366-8259 Fax: +886-3-5722892 Fax: +886-2-2363-0578 [email protected] [email protected]

46 Liu, Kuan-Lin Lu, Y.-J. Department of Chemistry Institute of Atomic and Molecular Sciences National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5715131-3427 Taiwan Fax: +886-3-5721614 Tel: +886-2-2366-8257 [email protected] Fax: +886-2-2362-0200 [email protected]

Luh, Wei-Tzou Luo, Liyang Department of Chemistry Department of Applied Chemistry National Chung Hsing University National Chiao Tung University 250, Kuo-Kuang Road 1001, Ta-Hsueh Rd. Taichung, 402 Hsinchu, 30010 Taiwan Taiwan Tel: +886-4-2285-2238 Tel: +886-3-5712121-56570 Fax: +886-4-2286-2547 Fax: +886-3-5723764 [email protected] [email protected]

Luo, Chu-Yung Luther, Klaus Institute of Atomic and Molecular Sciences Institut für Physikalische Chemie Academia Sinica der Universität Göttingen P. O. Box 23-166 Tammannstraβe 6 Taipei, 106 Göttingen, D-37077 Taiwan Germany Tel: +886-2-2366-8257 Tel: +49-551-393120 Fax: +886-2-2362-0200 Fax: +49-551-393-150 [email protected] [email protected]

Maier, John P. Martínez-Núñez, Emilio Department of Chemistry Departamento de Qijica Fisica University of Basel Facultad de Quimica Klingelbergstrasse 80 Avda das Ciencias s/n Basel, CH-4056 Santiago de Compostela, 15782 Switzerland Spain Tel: +41-612673826 Tel: +34-981-563100-14450 Fax: +41-612673855 Fax: +34-981-595012 [email protected] [email protected]

McCunn, Laura R. van de Meerakker, Bas James Franck Institute Dept. of Mole. Phys. University of Chicago Fritz-Haber-Institut der 5640 S. Ellis Ave. Max-Planck-Gesellschaft Chicago, IL 60637 Faradayweg 4-6 USA Berlin, D-14195 Tel: +1-773-702-9003 Germany Fax: + Tel: +49-30 84 1357 31 [email protected] Fax: +49-30 84 1356 03 [email protected]

47 Meijer, Gerard Merer, Anthony J. Dept. of Mole. Phys. Department of Chemistry Fritz-Haber-Institut der University of British Columbia Max-Planck-Gesellschaft 2036 Main Mall Faradayweg 4-6 Vancouver, B. C., V6T 1Z1 Berlin, D-14195 Canada Germany Tel: +1-604-822-2950 Tel: +49-30 84 1356 02 Fax: +1-604-822-2847 Fax: +49-30 84 1356-11 [email protected] [email protected]

Merkt, Frederic Miller, Barbara Physical Chemistry Lab. Department of Chemistry ETH Honggerberg, HCI Ohio State University Zurich, CH-8093 100 W. 18th Avenue Switzerland Columbus, OH 43210 Tel: +41-1-632-4367 USA Fax: +41-1-632-1021 Tel: +1-614-292-2569 [email protected] Fax: +1-614-292-1948 [email protected]

Miller, Terry A. Momose, Takamasa Department of Chemistry Division of Chemistry Ohio State University Graduate School of Science 100 W. 18th Avenue Kyoto, 606-8502 Columbus, OH 43210 Japan USA Tel: +81-75-753-4048 Tel: +1-614-292-2569 Fax: +81-75-753-4000 Fax: +1-614-292-1948 [email protected] [email protected]

Morrison, Marc D. Muller-Dethlefs, Klaus Physical and Theoretical Chemistry Department of Chemistry Laboratory The University of York University of Oxford York, YO10 5DD South Parks Road UK Oxford, OX1 3QZ Tel: +44-1904-434526 UK Fax: +44-1904-434527 Tel: +44-1865-275484 [email protected] Fax: +44-1865-275410 [email protected]

Nee, J. B. Nesbitt, David J. Department of Chemistry JILA/NIST, University of Colorado National Central University UCB 440 Chung-Li, 32054 Boulder, CO 80309-0440 Taiwan USA Tel: +886-3-422-7151x5311 Tel: +1-303-492-8857 Fax: +886-3-425-1175 Fax: +1-303-735-1424 [email protected] [email protected]

48 Neusser, Hans J. Neusser, Sebastian Physikalische Chemie Physikalische Chemie Technische Universität München Technische Universität München Lichtenbergstrasse 4 Lichtenbergstrasse 4 Garching, D-85748 Garching, D-85748 Germany Germany Tel: +49-89-289-13388 Tel: +49-89-289-13388 Fax: +49-89-289-13412 Fax: +49-89-289-13412 [email protected] [email protected]

Ni, Chi-Kung O'Brien, James J. Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica University of Missouri P. O. Box 23-166 8001 Natural Bridge Rd. Taipei, 106 St. Louis, MO 63121-4499 Taiwan USA Tel: +886-2-2366-8268 Tel: +1-314-516-5717 Fax: +886-2-2362-0200 Fax: +1-314-516-5342 [email protected] [email protected]

O'Brien, Leah C. Ogilvie, John F. Department of Chemistry Escuela de Quimica Southern Illinois University Universidad de Costa Rica Box 1652 San Pedro, San Jose 2060 Edwardsville, IL 62026-1652 Costa Rica USA Tel: +506-207-5325 Tel: +1-618-650-3562 Fax: +506-253-5020 Fax: +1-618-650-3562 [email protected] [email protected]

Pamidipati, Gayairi Hela Pan, Wan-Chun Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3425 Tel: +886-3-5715131-3427 Fax: +886-3-5721614 Fax: +886-3-5721614 [email protected] [email protected]

Pimentel, Giselle Pimentel, Andre S. NASA Goddard Space Flight Center NASA Goddard Space Flight Center Code 691 Code 691 Laboratory for Extraterrestrial Physics Laboratory for Extraterrestrial Physics Greenbelt, MD 20771 Greenbelt, MD 20771 USA USA Tel: +1-301-286-1427 Tel: +1-301-286-1427 Fax: +1-301-286-1683 Fax: +1-301-286-1683 [email protected] [email protected]

49 Pollack, Ilana B. Pradhan, Manik Department of Chemistry Institute of Atomic and Molecular Sciences University of Pennsylvania Academia Sinica Philadelphia, PA 19104-6323 P. O. Box 23-166 USA Taipei, 106 Tel: +1-215-898-5765 Taiwan Fax: +1-215-573-2112 Tel: +886-2-2366-8222 [email protected] Fax: +886-2-2362-0200 [email protected]

Radi, Peter P. Ramsay, Donald A. Paul Scherrer Institut Steacie Institute of Molecular Sciences Department General Energy National Research Council Villigen, CH-5232 Ottawa, K1A 0R6 Switzerland Canada Tel: +41-56-310-4127 Tel: +1-613-237-6667 Fax: +41-56-310-2199 Fax: + [email protected] [email protected]

Reid, Scott A. Rouillé, Gaël Marquette University Joint Laboratory Astrophysics Group Department of Chemistry Institut für Festkörperphysik P. O. Box 1881 Helmholtzweg 3 Milwaukee, WI 53201-1881 Jena, 07743 USA Germany Tel: +1-414-288-7565 Tel: +49-3641-9-47306 Fax: +1-414-288-7066 Fax: +49-3641-9-47308 [email protected] [email protected]

Rowland, F. Sherwood Schatz, George C. Dept. Chemistry and Earth System Sci. Department of Chemistry University of California, Irvine Northwestern University 516 Rowland Hall 2145 Sheridan Rd. Irvine, CA 92697-2025 Evanston, IL 60208-3113 USA USA Tel: +1-949-824-6016 Tel: +1-847-491-5657 Fax: +1-949-824-2905 Fax: +1-847-491-7713 [email protected] [email protected]

Serrano, Adela Seymour, Stephanie G. Departamento de Quimica Fisica I Dipartimento di Chimica Universidad Complutense de Madrid Universita di Perugia Madrid, 28040 Perugia, 06123 Spain Italy Tel: +34-913-944-126 Tel: +39-0755855514 Fax: +34-913-944-135 Fax: +39-0755855606 [email protected] [email protected]

50 Shida, Tadamasa Shiu, Vincent Weicheng Kanagawa Institute of Technology Institute of Atomic and Molecular Sciences 517-95 Iwakura Nagatanicho, Sakyo-ku Academia Sinica Kyoto, 606-0026 P. O. Box 23-166 Japan Taipei, 106 Tel: +81-75-722-7841 Taiwan Fax: +81-75-722-7841 Tel: +886-2-2366-8257 [email protected] Fax: +886-2-2362-0200 [email protected]

Simard, Benoit Skodje, Rex T. Steacie Institute for Molecular Sciences, Department of Chemistry NRC University of Colorado Room 1047-100 Sussex Drive Boulder, Colorado 80309 Ottawa, K1A 0R6 USA Canada Tel: +1-303-492-8194 Tel: +1-613-990-0977 Fax: +1-303-492-5894 Fax: +1-613-991-2648 [email protected] [email protected]

Slenczka, Alkwin Steimle, Timothy C. Department of Physical Chemistry Department of Chemistry and Biochemistry University of Regensburg Arizona State University Universitatsstrasse 31 Tempe, AZ 85287-1604 Regensburg, 92053 USA Germany Tel: +1-480-965-3265 Tel: +49-941-943-4487 Fax: +1-480-965-2747 Fax: +49-941-943-4488 [email protected] [email protected]

Sun, Ying-Chieh Suzuki, Toshinori Department of Chemistry Chemical Dynamics Laboratory National Taiwan Normal University Discovery Research Institute 88, Sec. 4, Ting Chou Rd. RIKEN (Institute of Physical and Chemical Taipei, 116 Research) Taiwan Wako, Saitama, 351-0198 Tel: +886-2-2935-0749x122 Japan Fax: +886-2-2932-4249 Tel: +81-48-467-1433 [email protected] Fax: +81-48-467-1403 [email protected]

Tang, Zichao ter Meulen, E. (Liesbeth) M. J. State Key Laboratory of Molecular Reaction University of Nijmegen Dynamics Toernooiveld 1 Center for Molecular Science Nijmegen, 6525 ED Institute of Chemistry The Netherlands The Chinese Academy of Sci. Tel: +31-243653022 Beijing, 100080 Fax: +31-243653311 China [email protected] Tel: +86-10-6255-8906 [email protected]

51 ter Meulen, J. (Hans) J. Thomas, Richard University of Nijmegen, Toernooiveld 1 Department of Physics Nijmegen, 6525 ED Stockholm University The Netherlands Alba Nova University Center Tel: +31-243653022 Stockholm, SE-106 91 Fax: +31-243653311 Sweden [email protected] Tel: +46-8-55378784 Fax: +46-8-55378601 [email protected]

Timonen, Raimo S. Tsai, Ming-Chang Laboratory of Physical Chemistry Institute of Atomic and Molecular Science University of Helsinki Academia Sinica P. O. Box 55 (A.I. Virtasen aukio 1) P. O. Box 23-166 Helsinki, FIN-00014 Taipei, 106 Finland Taiwan Tel: +358-9-1915-0302 Tel: +886-2-2366-8289 Fax: +358-9-1915-0279 Fax: +886-2-2362-0200 [email protected] [email protected]

Tseng, Shiang Y. Tseng, Chien-Ming Department of Applied Chemistry Institute of Atomic and Molecular Sciences National Chiao Tung University Academia Sinica Hsinchu, 30010 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5712121-56551 Taiwan Fax: +886-3-5723764 Tel: +886-2-2366-8268 [email protected] Fax: +886-2-2362-0200 [email protected]

Tsung, Jieh-Wen Tzeng, Wen Bih Department of Physics Institute of Atomic and Molecular Science National Tsing Hua University Academia Sinica 101, Sec. 2, Kuang Fu Road P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-2-2794-4108 Tel: +886-2-2366-8222 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Varberg, Thomas D. Vázquez, Saulo A. Department of Chemistry Departamento de Química Física Macalester College Facultad de Química 1600 Grand Ave. Avda das Ciencias s/n St. Paul, MN 55105-1899 Santiago de Compostela, 15782 USA Spain Tel: +1-651-696-6468 Tel: +34-981-563100-14228 Fax: +1-651-696-6432 Fax: +34-981-595012 [email protected] [email protected]

52 Vilesov, Alexander A. Vilesov, Andrey F. Department of Chemistry Department of Chemistry University of Southern California University of Southern California 920 West 37th Street 920 West 37th Street Los Angeles, CA 90089 Los Angeles, CA 90089 USA USA Tel: +1-213-821-2936 Tel: +1-213-821-2936 Fax: +1-213-740-3972 Fax: +1-213-740-3972 [email protected] [email protected]

Vilesov, Alla V. Wang, Chia C. Department of Chemistry University of California, Berkeley and University of Southern California Lawrence Berkeley National Laboratory 920 West 37th Street 2308 Warring St Apt 101 Los Angeles, CA 90089 Berkeley, CA 94704 USA USA Tel: +1-213-821-2936 Tel: +1-510-495-2412 Fax: +1-213-740-3972 Fax: +1-510-486-5311 [email protected] [email protected]

Wang, Chia Y. Wang, Li Department of Applied Chemistry Dalian Institute of Chemical Physics National Chiao Tung University 457 Zhongshan Road Hsinchu, 30010 Dalian, 116023 Taiwan China Tel: +886-3-5131516 Tel: +86-411-843-79243 Fax: +886-3-5723764 Fax: +86-411-846-75584 [email protected] [email protected]

Wei, Fang Western, Colin M. Department of Chemistry School of Chemistry Peking University University of Bristol Beijing, 100871 Cantock's Close China Bristol, BS8 1TS Tel: +86-10-627-53786 UK Fax: +86-10-627-51780 Tel: +44-117-928-8653 [email protected] Fax: +44-117-952-0612

Willitsch, Stefan Wong, Yung-Hao Physical Chemistry Lab. Institute of Atomic and Molecular Sciences ETH Honggerberg, HCI E209 Academia Sinica Zurich, CH-8093 P. O. Box 23-166 Switzerland Taipei, 106 Tel: +41-1633-4391 Taiwan Fax: +41-1632-1021 Tel: +886-2-2366-8257 [email protected] Fax: +886-3-2362-0200 [email protected]

53 Wu, Hsing-Chen Wu, Chia Yan Institute of Atomic and Molecular Science Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-5407 Tel: +886-2-2366-8250 Fax: +886-3-5722892 Fax: +886-2362-0200 [email protected] [email protected]

Wu, Di Wu, Yu Jong Institute of Theoretical Chemistry Department of Chemistry Jilin University National Tsing Hua University Changchun, 130023 Hsinchu, 30013 China Taiwan Tel: +86-431-8498964 Tel: +886-3-5715131-3346 Fax: +86-431-8945942 Fax: +886-3-5722892 [email protected] [email protected]

Wu, Hao-Wei Yang, Sheng-Kai Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-5407 Tel: +886-2-2366-8217 Fax: +886-3-5722892 Fax: +886-2-2362-0200 [email protected] [email protected]

Yang, Tzung R. Yang, Chia-Ming Department of Applied Chemistry Department of Chemistry National Chiao Tung University National Tsing Hua University Hsinchu, 30010 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5712121-56551 Tel: +886-3-5715131-3423 Fax: +886-3-5723764 Fax: + [email protected] [email protected]

Yu, Chin-Hui Yu, Jen-Shiang K. Department of Chemistry Dept. Biological Sci. Technol. National Tsing Hua University National Chiao Tung University 101, Sec. 2, Kuang Fu Road 75, Po-Ai Street Hsinchu, 30013 Hsinchu, 300 Taiwan Taiwan Tel: +886-3-5715131-3411 Tel: +886-3-5726111x56943 Fax: +886-3-5721534 Fax: +886-3-5729288 [email protected] [email protected]

54 Zhang, Alan Zhang, Guiqiu Department of Chemistry Institute of Atomic and Molecular Sciences University of California, Riverside Academia Sinica Riverside, CA 92521-0403 P. O. Box 23-166 USA Taipei, 106 Tel: +1-909-787-4197 Taiwan Fax: +1-909-787-4713 Tel: +886-2-2366-8217 [email protected] Fax: +886-2-2362-0200 [email protected]

Zhang, Bailin Zhang, Kevin Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica University of California, Riverside P. O. Box 23-166 Riverside, CA 92521-0403 Taipei, 106 USA Taiwan Tel: +1-909-787-4197 Tel: +886-2-2366-8257 Fax: +1-909-787-4713 Fax: +886-2-2362-0200 [email protected] [email protected]

Zhang, Xu Zhang, Jingsong Department of Chemistry and Biochemistry Department of Chemistry University of Colorado University of California, Riverside Campus Box 215 Riverside, CA 92521-0403 Boulder, CO 80309 USA USA Tel: +1-909-787-4197 Tel: +303-492-5406 Fax: +1-909-787-4713 Fax: +303-492-5894 [email protected] [email protected]

Zhao, Qiuxia Department of Chemistry University of California, Riverside Riverside, CA 92521-0403 USA Tel: +1-909-787-4197 Fax: +1-909-787-4713 [email protected]

55

Abrash, Samuel A. A2-19* Carvajal, Miguel A2-07 Adam, Allan G. B2-11 Casavecchia, P. B1-01*, B1-02*, af Ugglas, M. B2-20, C2-18 C1-01*, C1-02* Ahmed, K. C2-05 Castillo, J. F. A1-11*, B1-11*, Ahmed, Musahid B2-21 Chakraborty, T. M6 Akimoto, Hajime T2* Chang, Bor-Chen A2-03 Alam, M. S. C1-13* Chang, Chih-Wei A1-16* Al-Khalili, A. B2-18 Chang, Chushuan C1-06* Althorpe, Stuart C. C2-02* Chang, Wei-Zhong A2-03* Amaral, G. A. R4 Chekhlov, O. V. B2-05 Andersson, P. C2-19 Chen, Chun-Cing C2-21 Andrews, Django M2 Chen, Hongbing T3 Annesley, Chris B2-03, C2-03 Chen, Hui-Fen B1-09, B2-16* Aoiz, F. J. R4*, A1-11, B1-02, Chen, I-Chia M5*, A1-08, A1-15, B1-11 B1-15, B2-13, C1-10 Appadoo, Dominique R. T. A2-09 Chen, Kan-Sen C2-06 Arakawa, Hatsuko C1-16 Chen, Kuo-mei A2-08* Arnold, S. T. C2-18 Chen, Wei-Jan C2-06 Ashworth, Stephen, H. A2-11, B2-05 Chen, Wei-Kan A1-10* Baba, Masaaki C2-13 Chen, Yit-Tsong C2-21* Baek, Dae Youl C2-13 Cheng, C.-H. A1-15 Bahati, E. C2-19 Cheng, Chao Han B1-15 Bahou, Mohammed C1-09* Cheng, Mu-Jeng C1-14* Balaj, O. Petru W1 Cheng, Po-Yuan A1-10, C1-11 Balfour, Walter J. A2-10*, B2-11* Chervenkov, S. M6 Balint-Kurti, G. G. C2-05 Chiang, Chia-Chen B1-16 Balteanu, Iulia W1 Chiang, Su-Yu A2-15 Balucani, N. B1-01, B1-02 Choi, Jong-Ho M7* Banares, L. R4, A1-11, B1-02, Chou, Chun-Pang C2-16, C2-17* B1-11 Chou, Po-Han B2-16 Bannister, M. E. C2-19 Chou, Sheng-Lung B1-13* Barbera, Jack M2 Chou, Yung-Ching M5, A2-13*, B2-13* Barr, J. R4 Chu, Li-Kang B2-02 Bates, S. A. A2-18 Chu, San-Yan C1-14 Bauschlicher, C. W. B2-09 Cireasa, D. R. B1-10 Beaud, Paul A2-04 Clar, Justin A2-19 Bernath, P. A2-09*, B2-09* Clark, James M3 Beyer, M. K. W1 Cody, Regina J. B1-12 Bierbaum, Veronica M. B2-17 Cohen, Jodi A2-19 Bobbenkamp, R. B1-02 Colin, Reginald B2-04 Boering, Kristie A. A1-02 Cong, Shu-Lin B1-17 Bondybey, Vladimir E. W1* Continetti, Robert E. A1-01* Bonhommeau, D. W4 Curl, Robert F. T3* Braun, J. M6 Dagdigian, Paul J. B2-06* Brouard, Mark R3* Dam, N. J. A2-06 Brown, John T3 Davey, James B. C2-07 Brown, John M. A2-10, A2-11* de Goey, L. P. H. A2-06 Burrows, A.E. B2-09 Delaney, Cailin A2-19 Bussery-Honvault, B. B1-02 Deskevich, Mike C1-17 Butler, L. J. B1-05, C1-05* Diau, Eric Wei-Guang A1-16, B1-16 Caponna, G. B1-01, B1-02, C1-01, Dick, Bernhard B1-08 C1-02 Djurić, N. B2-18, B2-20 Cardenas, R. A2-18 Doi, Atsushi C2-13 Cartechini, L. B1-02 Dong, Feng C1-17

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Dulick, M. B2-09 Hu, Shui-Ming A2-21* Dung, Tzan-Yi A1-08 Huang, C. L. A1-13 Dunn, G. H. B2-18 Huang, Cheng-Liang M5, A1-03, C2-14* Dyakov, Yuri A. A1-03, A1-07*, B1-03 Huneycutt, A. J. B2-18 Dyke, John M. B2-15, C2-15 Hutson, Jeremy M. F2* Ebata, Takayuki C2-08 Imai, Yoshiyuki C1-08 Ehlerding, A. B2-18, B2-20, C2-18*, Innocenti, Fabrizio B2-15 C2-19 Ionescu, Ionela B2-03, C2-03 Elliott, N. L. B2-05 Ishida, Masayuki C1-04 Ellison, G. Barney A2-17, B2-17 Ishikawa, Haruki B2-08* Endo, Yasuki A2-01, B2-01*, C2-01 Jacox, Marilyn E. A2-16* Eskola, Arkke A1-12 Jakubek, Zygmunt J. C2-11 Evertsen, R. A2-06 Janata, E. C1-13 Fan, Haiyan B2-03, C2-03 Jensen, Per A2-07* Fernandez-Ramos, A. A1-11 Jensen, Roy H. B2-11 Fink, E. H. A2-05 Jochnowitz, Evan B. A2-17 Fitzpatrick, J. A. J. B2-05 Juanes-Marcos, Juan Carlos C2-02 Fujii, Asuka C2-08* Kable, Scott C1-15 Fujimura, Yo C1-08* Kajimoto, Okitsugu C1-08 Geballe, T. R. B2-18 Kalhouri, S. B2-18 Georgiev, S. M6 Kanamori, H. A2-14* Geppert, W. D.* B2-20*, C2-18, C2-19 Kasahara, Shunji C2-13 Gerber, Thomas A2-04 Kato, Hajime C2-13* Gordon, Iouli A2-09 Kato, Shuji B2-17 Graham, W. R. M. A2-18* Katoh, Kaoru A2-01*, C2-01* Greenslade, Margaret E. C2-07 Kensy, Uwe B1-08 Guss, Joseph C1-15* Kerenskaya, Galina F1 Haber, Louis M3 Kim, Heong Hyun B2-21 Halberstadt, Nadine W4* Knopp, Gregor A2-04 Han, Huei-Lin B2-02* Kobayashi, Kaori A2-02* Han, Jiaxiang T3 Konen, Ian M. B2-07, T5 Han, Ke-Li B1-17* Krisch, M. J. B1-05, C1-05 Hancock, G. A1-17 Kumae, Takashi C1-16* Hao, Xi-Yun A1-14, B1-14 Kung, A. H. M5, C2-06 Hardimon, Sarah B2-10 Kurniawan, Fendi A2-15 Hattori, T. B2-19 Lai, Ta-Jen C1-11 He, Guo-Zhong B1-17 Laperle, Ghristopher, M. A1-01 He, Sheng-Gui A2-21 Larsson, M. B2-18*, B2-20, C2-18, Heaven, Michael C. F1* C2-19 Hela, P. G. A1-15* Launay, J.-M. B1-02 Hellberg, F. B2-18, B2-20, C2-18, Lee, P. C. B2-14 C2-19 Lee, Sheng-Jui C1-10* Hepburn, John C2-20* Lee, Shih-Huang A1-05*, A1-08 Higashiyama, Tomohiko C1-04 Lee, Yin-Yu A1-08* Hirota, Eizi C2-01 Lee, Yuan T. A1-02, A1-03, A1-05, Ho, Jr-Wei A1-10, C1-11* A1-07, A1-08, B1-03 Hodges, Philip J. A2-11 Lee, Yuan-Pern A1-09, B1-09, B1-13, Honma, Kenji C1-04* B2-02, B2-04, B2-16, Honvault, P. B1-02 C1-09, C2-04, C2-16, Hougen, Jon T. M5, C2-14 C2-17 Hsu, Hsu Chen C1-03 Leone, Stephen R. M3* Hsu, Hui-Ju A2-03 Leonori, F. B1-01, C1-01 Hsu, Yen-Chu F4*, A2-13, C2-06 Lester, Marsha I. T5*, B2-07, C2-07* Hu, Qichi C2-20 Li, Eunice X. J. T5, B2-07 Hu, Shuiming T3 Li, Ru-Jiao A1-14, B1-14

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Li, Runhua B2-11 Nesbitt, Fred L. B1-12 Li, Zhi-Ru A1-14, B1-14* Neumark, Daniel M. B2-21 Liao, Yean-An C2-06 Neusser, H. J. M6* Lin, Chia-Shih A2-03 Ni, Chi-Kung M5, R5*, A1-03 Lin, Hai A2-07, A2-21 A1-07, B1-03, C1-03, Lin, I-Feng A2-15* C2-14 Lin, Jim J. R1, A1-02*, A1-06, Nimlos, Mark R. A2-17 A1-08, A2-13, B1-06 Nizamov, Boris B2-06 Lin, M. C. T4*, A1-13, B1-13 Novotny, O. B2-18 Lin, Ming-Fu B1-03* Obernhuber, Thorsten B1-08 Lin, S. H. A1-07 O'Brien, James J. C2-10* Lin, Sheng Hsien A1-03, B1-03 O'Brien, Leah C. B2-10*, C2-10 Lineberger, W. Carl M2* Oguchi, T. B2-19 Ling, Ching-Yao B1-16 Österdahl, F. B2-18, B2-20, C2-18 Liu, An-Wen A2-21 Oum, Kawon C1-12 Liu, Chen-Lin C1-03*, C2-14 Paál, A. B2-18 Liu, Ching-Ping B2-04*, C2-04* Pan, Wan-chun A1-08 Liu, Kopin R1*, A1-06, B1-06, Parker, David H. B1-06 C1-06 Payne, Walter A. B1-12 Liu, Kuan Lin B1-15* Peers, J. R. D. A2-12 Liu, Suet-Yi B1-09 Perri, Mark J. A1-02 Liu, Y. B1-05 Peterka, Darcy S. B2-21 Lo, Wen-Jui B2-16 Petrignani, A. C2-19 Luh, Wei-Tzou C2-09* Pettersson, J. B. C. C2-19 Luo, Chu-Yung C1-06 Pimentel, Andre S. B1-12* Luo, Liyang B1-16* Pino, G. A. R4 Luther, Klaus C1-12* Plenge, Jürgen M3 Maier, John P. F5* Pollack, Ilana B. T5, B2-07* Mann, Jennifer E. A1-01 Radi, Peter P. A2-04* Marques, Jorge M. C. B1-07 Ram, R. S. B2-09 Marshall, Mark D. C2-07 Ramsay, D. A. A2-05* Martínez-Núñez, Emilio A1-11, B1-07*, C1-07 Rao, B. S. M. C1-13 Matsui, H. B2-19* Rathbone, Jeff M2 McCall, B. J. B2-18 Reid, Scott A. B2-03*, C2-03*, C2-04 McCoy, Anne M2 Rittby, C. M. L. A2-18 McCunn, L. R. B1-05*, C1-05 Rixon, S. J. A2-12 Mebel, Alexander M. A1-03, A1-07 Robbins, D. L. A2-18 Meijer, Gerard M4*, A2-20 Rosen, S. C2-19 Merer, Anthony J. A2-12*, C2-06 Rowland, F. Sherwood T1* Merkt, Frédéric W2*, B2-15, C2-15 Roy, Robert J. C2-12 Mikami, Naohiko B2-08, C2-08 Sadasivan, Shaji C2-06 Millar T. J. B1-05, B2-20, C1-05 Saito, Shuji A2-02 Miller, Terry A. B2-12* Sanford, Todd M2 Mitsutani, Kazuya C1-08 Saunders, M. A1-17 Miyazaki, Mitsuhiko C2-08 Saykally, R. J. B2-18 Moise, A. B1-10 Schatz, George, C. M8* Momose, Takamasa W5* Schnupf, Udo F1 Morrison, M. A1-17* Seetula, Jorma A1-12 Müller, Astrid M3 Segoloni, E. B1-01, B1-02, C1-01, Muntean, Felician M2 C1-02 Muramoto, Yasuhiko B2-08 Sekiguchi, Kentaro C1-12 Nakhate, Sanjay C2-11 Semaniak, J. B2-18, B2-20, C2-18 Neau, A. B2-18 Shayesteh, Alireza A2-09 Nee, J. B. B2-14* Shephard, Scott A. B2-11 Nesbitt, David J. C1-17* Shih, H.-T. A1-15

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Shiu, Vincent W. C. R1, A1-06, B1-06* Viel, A. W4 Shu, J. B1-05, C1-05 Viggiano, A. A. C2-18 Siglow, K. M6 Vilesov, Andrey F. W3* Simard, Benoit C2-11* Volpi, G. G. B1-01, C1-01, C1-02 Skodje, Rex T. R2* Wallace, Lloyd A2-10 Slenczka, Alkwin B1-08* Wang, Bing-Qiang A1-14, B1-14 Soldan Pavel F2 Wang, Chia C. B2-21* Staicu, A. A2-06 Wang, Jinguo C2-13 Stanton, John F. A2-17 Wang, N. S. A1-13 Steimle, Timothy C. F3* Wang, P. M6 Stranges, D. B1-01 Wang, T. Y. A1-13 Suma, Kohsuke B2-01 Western, C. M. B2-05*, C2-05* Sumiyoshi, Yoshihiro A2-01, B2-01, C2-01 Whitney, Erin C1-17 Sun, Chia-Chung A1-14, B1-14 Willitsch, Stefan B2-15*, C2-15* Sun, Ju-Long B1-17 Wu, Chia-Yan A1-09*, B1-09 Suzuki, Toshinori M1* Wu, Di A1-14*, B1-14 Tamada, Hisashi C1-08 Wu, Hsing-Chen C2-21 Tang, Kuo-Chun B1-15 Wu, Malcom B1-06 Tang, Sheunn-Jiun A2-13 Wu, Yu-Jong A1-09, C2-16*, C2-17 Taylor, Mark M2 Xin, Ju B2-03, C2-03 ter Meulen, J. J. A2-06*, B1-10* Xu, Z. F. T4, A1-13 Teslja, Alexey B2-06 Yang, Chia-Ming C1-11 Thiel, Walter A2-07 Yang, J. C. B2-14 Thomas, R. D. B2-18, B2-20, C2-18, Yang, Sheng-Kai B1-09* C2-19* Yang, Xueming A1-08 Thompson, Warren E. A2-16 Yang, Yi-Han C2-21 Thweatt, Daivd T3 Yin, Hong-Ming B1-17 Timonen, Raimo A1-12* Yoshida, K. A2-14 Torres, I. R4 Yuan, Yan A1-04, B1-04 Troya, Diego M8 Yurchenko, Sergei N. A2-07 Tseng, Chien-Ming A1-03*, C2-21 Zachwieja, Mirek C2-11 Tseng, S. Y. A1-13* Zhang, Bailin R1, A1-06* Tulej, Marek A2-04 Zhang, Guiqiu C2-06* Ueno, Taketoshi A2-01 Zhang, Jingsong A1-04*, B1-04* van de Meerakker, S. Y. T. A2-20* Zhang, Xu A2-17*, B2-17* van der Zande, W. J. C2-19 Zhaunerchyk, V. C2-18, C2-19 van Oijen, J. A. A2-06 Zheng, Jing-Jing A2-21 van Wyngarden, Annalise, L. A1-02 Zhou, Jingang R1 Vane, C. R. C2-19 Zhou, Weidong A1-04, B1-04 Vanhaecke, N. A2-20 Zhu, Qing-Shi A2-21 Varberg, Thomas D. A2-11, C2-12* Zhu, R. S. T4 Varne, Mychel Elizabeth A2-17 Zolot, Alex C1-17 Vázquez, Saulo A. A1-11, B1-07, C1-07*

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Taking Dye Lasers To New Levels

• Simple access to deep UV Quanta-Ray/Sirah system includes the highest quality laser optics, the latest innovations in resonator design and full computer control. In addition the perfect and mid-IR match of Sirah’s short dye laser cavity with longer Nd:YAG pulses from • Linewidths as narrow as 0.03 cm-1 Quanta-Ray gives rise to narrower linewidth. • High power capability to 260 mJ/pulse With many performance enhancing options to choose from, a Quanta-Ray/Sirah •Conversion efficiencies to 28% system can deliver millijoules of pulse energy from UV wavelengths as short as • Full computer control 189 nm to 10 microns in the IR. And with linewidths as narrow as 0.03 cm-1, a Quanta-Ray/Sirah dye laser system is perfect for high-resolution applications such as state-to-state chemistry.

HsinChu Office Kaohsiung Office SCHMIDT SCIENTIFIC Taiwan Ltd. 300新竹市公道五路二段120號4樓之6 807高雄市三民區九如一路502號15樓之1 實密科技股份有限公司 4F-6, No.120, Sec.2, Gongdaowu Rd., 1, 15F, No.502, Chiuzhu-I Rd, Sanming District, http://www.schmidt.com.tw Hsinchu, 300, Taiwan(R.O.C.) Kaohsiung, 807, Taiwan (R.O.C.) Tel: +886-3-5166388 Fax: +886-3-5166389 Tel: +886-7-3838559 Fax: +886-7-3843518

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Programme of the 27th International Symposium on Free Radicals Date July 25 July 26 July 27 July 28 July 29 July 30 Time Sunday Monday Tuesday Wednesday Thursday Friday Chair: YP Lee Chair: SH Lin Chair: Miller Chair: Hepburn Chair: Nesbitt 08:30−09:10 Opening: YT Lee T1 Rowland W1 Bondybey R1 Liu F1 Heaven 09:10−09:50 M1 Suzuki T2 Akimoto W2 Merkt R2 Skodje F2 Hutson 09:50−10:20 Coffee Break Coffee Break Coffee Break Coffee Break Chair: Larsson Chair: ter Meulen Chair: Jacox Chair: Butler Chair: Merer 10:20−11:00 M2 Lineberger T3 Curl W3 Vilesov R3 Brouard F3 Steimle 11:00−11:40 M3 Leone T4 MC Lin W4 Halberstadt R4 Aoiz F4 Hsu 11:40−12:20 M4 Meijer T5 Lester W5 Momose R5 Ni F5 Maier 12:30−14:00 Lunch (B1F, Fu-Chuan Room) Box Lunch Lunch (B1F) Chair: Colin 1-min Oral: C1 & C2 14:00−14:40 M5 Chen IAMS Chair: Zhang 14:40−15:20 M6 Neusser Lab Tour Poster Presentations Conference Tour Tour to 15:20−15:50 Registration Coffee Break (depart at 14:00 W1~W5, R1~R5 (depart at 13:10 Hsinchu (15:00~21:00) Chair: Continetti from the front F1~F5 from the front (depart at 14:00 15:50−16:30 (10F) M7 Choi entrance) C1-01~C1-17 entrance) from the front 16:30−17:10 M8 Schatz or C2-01~C2-21 entrance) 17:10−17:50 Symposium Photo Free Dinner at 17:30 18:00−19:30 Dinner (B1F) Dinner (B1F) (BBQ at Y-S Club) Reception 1-min Oral: A1 & A2 1-min Oral: B1& B2 Cultural Evening Banquet at 18:30 19:30−20:30 (1F) Chair: Dagdigian Chair: Shida (at Taipei EYE) (12F) 20:30−22:30 (Grand Garden) Poster Presentations Poster Presentations (buses depart at (Skylounge) M1~M8 T1~T5 19:45 from A1-01~A1-17 B1-01~B1-17 Yuan-Shan Club) A2-01~A2-21 B2-01~B2-21

Taking Dye Lasers To New Levels Quanta-Ray/Sirah system includes the highest quality laser optics, the latest • Simple access to deep UV innovations in resonator design and full computer control. In addition the perfect and mid-IR match of Sirah’s short dye laser cavity with longer Nd:YAG pulses from -1 • Linewidths as narrow as 0.03 cm Quanta-Ray gives rise to narrower linewidth. • High power capability to 260 mJ/pulse With many performance enhancing options to choose from, a Quanta-Ray/Sirah •Conversion efficiencies to 28% system can deliver millijoules of pulse energy from UV wavelengths as short as -1 • Full computer control 189 nm to 10 microns in the IR. And with linewidths as narrow as 0.03 cm , a Quanta-Ray/Sirah dye laser system is perfect for high-resolution applications such as state-to-state chemistry.

HsinChu Office Kaohsiung Office SCHMIDT SCIENTIFIC Taiwan Ltd. 300新竹市公道五路二段120號4樓之6 807高雄市三民區九如一路502號15樓之1 實密科技股份有限公司 4F-6, No.120, Sec.2, Gongdaowu Rd., 1, 15F, No.502, Chiuzhu-I Rd, Sanming District, http://www.schmidt.com.tw Hsinchu, 300, Taiwan(R.O.C.) Kaohsiung, 807, Taiwan (R.O.C.) Tel: +886-3-5166388 Fax: +886-3-5166389 Tel: +886-7-3838559 Fax: +886-7-3843518 Important Information

Registration and Symposium Office Hours The symposium office will be located in Lan Tin on the southwestern end of the 10th floor (see map on page 23). It will be open 15:00−21:00 on July 25 (Sunday), 08:00−13:00 and 14:00−1700 on July 26 (Monday), and 08:00−13:00 on July 27−30 (Tuesday–Friday). Please register at the Symposium office during these office hours.

Reception (July 25, Sunday) A buffet-style dinner reception will be held in the Grand Garden (west end of the Lobby level) from 18:00 to 22:00. Please bring your invitation card and proceed directly to the Spring Room on the southern side of the Grand Garden. Please see the map on page 22.

Scientific Programmes All the scientific programme is held on the 10th floor of the Grand Hotel. The lecture sessions and oral briefs before poster sessions all take place in the Auditorium. The posters are located in the Chang-Chin (Evergreen) Room and the Song-Bo (Pine) Room on the west side of the Auditorium. Please refer to the floor plan on page 23.

Meals You will receive tickets for meals, which you need to enter the dining room. Breakfast is included in the room charge and is served between 06:30 to 10:00 at the Grand Garden (west end of the Lobby level). You should receive tickets for breakfast upon checking in the Grand Hotel, and tickets for other meals upon registration at the Symposium Office on 10F. Lunch and dinner are served in the Fu-Chuan Room (B1F) except as follows: July 28 (Wednesday) – Mongolian BBQ at the Yuan Shan Club, July 29 (Thursday) – box lunch to be distributed outside the Auditorium after the morning session, and July 29 (Thursday) − Symposium Banquet at the Kung-Lung Skylounge (12F).

Invited Oral Presentation Overhead projectors and PC computers (Windows XP or 2000/MS-Office/CD-ROM/ USB port) connected to a multimedia projector will be available. Please upload your files or connect your computer 10 min before each session begins. Please keep your talk within 30−35 min to allow 5−10 min for discussion. Please use large fonts for your presentation because the Auditorium has large theatrical seating. You are encouraged to mount a poster or a copy of PowerPoint slides of your talk for further discussion; the identification number of your poster is the same as that of your oral presentation.

1 Posters The size of the poster board is 90 cm (H) × 180 cm (W). All posters should be mounted before 16:00 on July 26 (Monday), remain posted until noon July 29 (Thursday), and be dismounted before midnight July 29 (Thursday). Each poster session will begin with a brief oral presentation, 1 minute for each poster, in the Auditorium. Please prepare less than 3 transparencies. Only overhead projectors, but not multimedia projectors, are used in these briefing sessions. To save time, the next presenter should move to the front before his or her turn.

Poster Identifications

XY - ZZ

Session Room No. Poster Number

X = A : July 26 (Monday) evening, 19:30−22:30 X = B : July 27 (Tuesday) evening, 19:30−22:30 X = C : July 28 (Wednesday) afternoon, 14:00−17:00 Y = 1 : Chang-Chin Room Y = 2 : Song-Bo Room

Symposium Photo (July 26, Monday) A symposium photograph will be taken on 17:20, July 26 (Monday). Please proceed to the front of the hotel after the lecture. Accompanying persons are encouraged to join this activity.

Lab Tour to IAMS (July 27, Tuesday) Please register before 12:00 July 26 (Monday) if you have not done so. Meet at the lobby at 14:00 on July 27 (Tuesday). Visit Chemical Dynamics and Spectroscopy Groups of the Institute of Atomic and Molecular Sciences, Academia Sinica, located on the campus of National Taiwan University. Buses depart from IAMS for the Grand Hotel on 17:00.

Cultural Evening on July 28 (Wednesday) We shall begin at 17:30 with a Mongolian BBQ dinner at the Yuan Shan Club located beside the Grand Hotel (see map on p. 22 or 24). After dinner, at 19:45 buses will take us to the Taipei EYE Theater (http://www.taipeieye.com/eng/) where we shall enjoy an evening of authentic Taiwanese and Chinese traditional performances beginning at 20:30. The programme includes singing and dancing of aboriginal tribes and a Peking opera.

2 Before the performance and during the intermission, there are interactive activities and you shall have opportunities to see how performers make up and how they play traditional Chinese instruments. English subtitles are provided. The performance lasts ~100 min.

Conference Tour (July 29, Thursday) Buses will leave at 13:10 from the Grand Hotel. The National Palace Museum (http://www.npm.gov.tw/english/index-e.htm) contains the world’s largest collection of Chinese art treasures. Guided tours in several groups will be provided. Buses depart from the Museum at 17:00.

Conference Banquet (July 29, Thursday) The conference banquet begins at 18:30 at the Kung-Lung Skylounge on the 12th floor. It will be a traditional ten-course round-table banquet. The banquet speaker is Professor Jon Hougen.

Lab Tour to Hsinchu (July 30, Friday) Please register before 12:00 July 28 (Wednesday) if you have not done so; this tour is limited to 50 persons. Buses depart on 14:00, July 30 (Friday). The ride lasts ~1 h. Visit the National Synchrotron Radiation Research Center and the Laser Chemistry Laboratories of the National Tsing Hua University. Have dinner at a local buffet-style seafood restaurant and return to the Grand Hotel ~22:30. For those who have an evening flight on July 30, we can arrange taxis to take you to the airport (~50 min ride from Hsinchu) after visiting National Tsing Hua University. Please arrange with the Symposium Office.

Access to Internet Access to a rapid internet service (ADSL) is available from your room, for which the charge is NT$500/day. Computers of limited number will be available in the office area for internet access during office hours. If possible, we will arrange a few wireless access points on the 10th floor so that you can use your notebook to gain access.

Tours for Accompanying Persons The tours listed on page 25 are provided by Edison Travel Service (886-2-25635313, 25634621, 25416785, and 25373838, http://www.edison.com.tw/) and administered by the Grand Hotel (ext. 1810 and 1811). If you did not indicate your choices on your registration form but would like to join these tours, please contact our staff in the Symposium Office and pay the regular fare. You may also take the tour at a date different

3 from what we indicated below; please contact the Grand Hotel directly. All tours depart from the custom service desk at the lobby. Please note that the Symposium uses a tour voucher different from that of the Grand Hotel.

Shuttle Bus between the Grand Hotel and CKS Airport The Toward You Air Bus Corp. (http://www.airbus.com.tw, 0800-088-626 or (02)2630- 9976) now operates a shuttle bus (about 40 seats) between CKS airport and the Grand Hotel. Fares are NT$100 for adults and NT$50 for children or adults over 65. The trip takes about 40 to 60 minutes, depending on the traffic. Under normal circumstances you need no reservation. For updated information, please contact the hotel concierge at ext. 1810. The present schedules are as follows:

From Hotel Main Entrance From CKS Terminal 1 From CKS Terminal 2 06:30 07:30 07:20 07:30 08:30 08:20 09:30 10:30 10:20 10:30 11:30 11:20 12:30 13:30 13:20 13:30 14:30 14:20 15:30 16:30 16:20 16:30 17:30 17:20 18:30 19:30 19:20

Symposium Shuttle Bus to CKS Airport A few free shuttle buses will be arranged to go to CKS airport from the Grand Hotel on July 30 (Friday) and July 31 (Saturday) at times not covered by the above Air Bus schedule. Please read the schedule at the conference desk and register before 12:00 July 28 (Wednesday). If the bus schedule does not match with your flight, please arrange a taxi with the Grand Hotel (~NT$1000).

Special Notice on Coffee Breaks Please note that it is not permitted to bring food and beverages into the Auditorium. The coffee breaks will take place in the corridors west of the Auditorium. Because space is limited, please move to the Chang-Chin Poster Room after you obtain your beverage or food.

4 Programme of the 27th International Symposium on Free Radicals July 25 July 26 July 27 July 28 July 29 July 30 Sunday Monday Tuesday Wednesday Thursday Friday Chair: YP Lee Chair: SH Lin Chair: Miller Chair: Hepburn Chair: Nesbitt 08:30−09:10 Opening: YT Lee T1 Rowland W1 Bondybey R1 Liu F1 Heaven 09:10−09:50 M1 Suzuki T2 Akimoto W2 Merkt R2 Skodje F2 Hutson 09:50−10:20 Coffee Break Coffee Break Coffee Break Coffee Break Coffee Break Chair: Larsson Chair: ter Meulen Chair: Jacox Chair: Butler Chair: Merer 10:20−11:00 M2 Lineberger T3 Curl W3 Vilesov R3 Brouard F3 Steimle 11:00−11:40 M3 Leone T4 MC Lin W4 Halberstadt R4 Aoiz F4 Hsu 11:40−12:20 M4 Meijer T5 Lester W5 Momose R5 Ni F5 Maier 12:30−14:00 Lunch (B1F, Fu-Chuan Room) Box Lunch Lunch (B1F) Chair: Colin 1-min Oral: C1 & C2 14:00−14:40 M5 Chen IAMS Chair: Zhang 14:40−15:20 M6 Neusser Lab Tour Poster Presentations Conference Tour Tour to 15:20−15:50 Registration Coffee Break (depart at 14:00 W1~W5, R1~R5 (depart at 13:10 Hsinchu (15:00~21:00) Chair: Continetti from the front F1~F5 from the front (depart at 14:00 15:50−16:30 (10F) M7 Choi entrance) C1-01~C1-17 entrance) from the front 16:30−17:10 M8 Schatz or C2-01~C2-21 entrance) 17:10−17:50 Symposium Photo Free Dinner at 17:30 18:00−19:30 Dinner (B1F) Dinner (B1F) (BBQ at Y-S Club) Banquet at 18:30 Reception 1-min Oral: A1 & A2 1-min Oral: B1& B2 Cultural Evening (12F) 19:30−20:30 (1F) Chair: Dagdigian Chair: Shida (at Taipei EYE) (Skylounge) 20:30−22:30 (Grand Garden) Poster Presentations Poster Presentations (buses depart at M1~M8 T1~T5 19:45 from A1-01~A1-17 B1-01~B1-17 Yuan-Shan Club) A2-01~A2-21 B2-01~B2-21

Programme for Accompanying Persons July 25 July 26 July 27 July 28 July 29 July 30 Sunday Monday Tuesday Wednesday Thursday Friday

08:30−09:10 Tour 3: 09:10−09:50 Cultural Tour Tour 5: Tour 1: Tour 7: 09:50−10:20 Yangmingshan Coffee Break Taipei City Northern Coast Tour 8: National Park & 10:20−11:00 Tour Tour Taroko (Marble) Hot-Spring Tour 11:00−11:40 Gorge Tour 11:40−12:20 12:30−14:00 Lunch (B1F, Fu-Chuan Room) Box Lunch Lunch (B1F)

14:00−14:40 Tour 4: Wulai Aboriginal Tour 6: Tour 2: Conference Tour 14:40−15:20 Village Tour Chiufen Village & Registration Folk Art (depart at 13:10 Tour to 15:20−15:50 Northeast Coast (15:00~21:00) Tour from the front Hsinchu 15:50−16:30 IAMS Lab Tour Tour (10F) entrance) (depart at 14:00 16:30−17:10 from the front 17:10−17:50 Symposium Photo Dinner at 17:30 entrance) 18:00−19:30 Dinner (B1F) Dinner (B1F) (BBQ at Y-S Club) Banquet at 18:30 Reception Cultural Evening (12F) 19:30−20:30 (1F) (at Taipei EYE) (Skylounge) 20:30−22:30 (Grand Garden) (buses depart at 19:45 from Yuan-Shan Club)

5 Scientific Programme and Symposium Schedule

Monday, 26 July, 2004

SESSION 1 Chair: Y.-P. Lee, National Tsing Hua University, Hsinchu, Taiwan

08:30 – 09:10 Opening Address - Y. T. Lee, Academia Sinica, Taipei, Taiwan

09:10 – 09:50 M1: T. Suzuki, RIKEN, Wako, JAPAN (recipient of Broida Award) Chemical Dynamics Studied by Time-Resolved Photoelectron Imaging

09:50 – 10:20 interval for refreshments

SESSION 2 Chair: M. Larsson, Stockholm University, Stockholm, Sweden

10:20 – 11:00 M2: W. C. Lineberger, JILA / University of Colorado, Boulder, CO, USA Time Resolved Solvent Rearrangement Dynamics

11:00 – 11:40 M3: S. R. Leone, University of California, Berkeley, CA, USA Ultrafast X-Rays: Time-Resolved Photoelectron Processes in Molecular Dissociation

11:40 – 12:20 M4: G. Meijer, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany & FOM Institute for Plasmaphysics Rijnhuizen, Nieuwegein, The Netherlands Manipulation of Molecules with Electric Fields

12:30 – 14:00 Lunch (Fu-Chuan Room, B1F)

SESSION 3 Chair: R. Colin, Universite Libre de Bruxelles, Brussels, Belgium

14:00 – 14:40 M5: I-C. Chen, National Tsing Hua University, Hsinchu, Taiwan Rotationally Resolved Spectra of Transitions Involving Motion of the ~ ~ Methyl Group of Acetaldehyde in the System A 1A″− X 1A′ 14:40 – 15:20 M6: H. J. Neusser, Technische Universität München, Garching, Germany High Resolution Mass Selective UV Spectroscopy of Molecules and Clusters

15:20 – 15:50 interval for refreshments

6

SESSION 4 Chair: R. E. Continetti, University of California, San Diego, CA, USA

15:50 – 16:30 M7: J.-H. Choi, Korea University, Seoul, Korea Reaction Dynamics of Atomic Oxygen with Hydrocarbon Radicals

16:30 – 17:10 M8: G. C. Schatz, Northwestern University, Evanston, IL, USA Theoretical Studies of Reactions of Hyperthermal O(3P)

17:10 – 17:50 Symposium Photo

18:00 – 19:30 Dinner (Fu-Chuan Room, B1F)

SESSION 5 Chair: P. J. Dagdigian, Johns Hopkins University, Baltimore, MD, USA

19:30 – 20:30 Brief oral presentations of posters: Sessions A1 & A2 (Auditorium)

20:30 – 22:30 Poster presentations A1-01 to A1-17, M1 to M8 (Chang-Chin Room) A2-01 to A2-21 (Song-Bo Room)

7 Tuesday, 27 July, 2004

SESSION 1 Chair: S. H. Lin, IAMS, Academia Sinica, Taipei, Taiwan

8:30 – 9:10 T1: F. S. Rowland, University of California, Irvine, CA, USA Hydrocarbons in the Atmosphere

9:10 – 9:50 T2: H. Akimoto, Frontier Res. Sys. for Global Change, Yokohama, Japan

Atmospheric Measurements of OH and HO2 Radicals in a Marine Boundary Layer

9:50 – 10:20 interval for refreshments

SESSION 2 Chair: H. J. ter Meulen, Univ. of Nijmegen, Nijmegen, The Netherlands

10:20 – 11:00 T3: R. F. Curl, Rice University, Houston, TX, USA Infrared Laser Spectroscopy and Chemical Kinetics of Free Radicals

11:00 – 11:40 T4: M. C. Lin, Emory University, Atlanta, GA, USA Ab Initio Studies of Free Radical Reactions of Interest to Atmospheric Chemistry

11:40 – 12:20 T5: M. I. Lester, University of Pennsylvania, Philadelphia, PA, USA Significant OH Radical Reactions in the Atmosphere: A New View

12:30 – 14:00 Lunch (Fu-Chuan Room, B1F)

Meeting of the International Organizing Committee (Rm. 102, 1F)

14:00 – 17:50 IAMS Laboratory Tours

18:00 – 19:30 Dinner (Fu-Chuan Room, B1F)

SESSION 3 Chair: T. Shida, Kanagawa Institute of Technology, Kyoto, Japan

19:30 – 20:30 Brief oral presentations of posters: Sessions B1 & B2 (Auditorium)

20:30 – 22:30 Poster presentations B1-01 to B1-17, T1 to T5 (Chang-Chin Room) B2-01 to B2-21 (Song-Bo Room)

8 Wednesday, 28 July, 2004

SESSION 1 Chair: T. A. Miller, Ohio State University, OH, USA

8:30 – 9:10 W1: V. E. Bondybey, Technische Universität München, Garching, Germany & University of California, Irvine, CA, USA Free Electrons: The Simplest Free Radicals of them All

9:10 – 9:50 W2: F. Merkt, ETH Zürich, Zürich, Switzerland High-Resolution Photoelectron Spectroscopic Studies of Ions and Radicals

9:50 – 10:20 interval for refreshments

SESSION 2 Chair: M. E. Jacox, NIST, Gaithersburg, MD, USA

10:20 –11:00 W3: A. F. Vilesov, Univ. of Southern California, Los Angeles, CA, USA Helium Droplets as a Unique Nano-Matrix for Molecules and Molecular Aggregates

11:00 – 11:40 W4: N. Halberstadt, CNRS & Univ. Paul Sabatier, Toulouse, France Non-adiabatic Dynamics of Ionized Neon Clusters inside Helium Nanodroplets

11:40 – 12:20 W5: T. Momose, Kyoto University, Kyoto, Japan Free Radicals in Quantum Crystals: A Study of Tunneling Chemical Reactions

12:30 – 13:50 Lunch (Fu-Chuan Room, B1F)

SESSION 3 Chair: J. Zhang, University of California, Riverside, CA, USA

14:00 – 15:00 Brief oral presentations of posters: Sessions C1 & C2 (Auditorium)

15:00 – 17:00 Poster presentations C1-01 to C1-17, W1 to W3 (Chang-Chin Room) C2-01 to C2-21, W4, W5, R1 to R5, F1 to F5 (Song-Bo Room)

17:30 – 19:45 Dinner (Mongolian BBQ at Yuan Shan Club)

20:00 – 22:30 Cultural Evening (Taipei EYE Theater)

9 Thursday, 29 July, 2004

SESSION 1 Chair: J. Hepburn, Univ. of British Columbia, Vancouver, B.C., Canada

8:30 – 9:10 R1: K. Liu, IAMS, Academia Sinica, Taipei, Taiwan From Pair Correlation to Reactive Resonance in Polyatomic Reactions

9:10 – 9:50 R2: R. T. Skodje, IAMS, Academia Sinica, Taipei, Taiwan & University of Colorado, Boulder, CO, USA State-to-State-to-State Dynamics of Chemical Reactions: The Control of Detailed Collision Dynamics by Quantized Bottleneck

9:50 – 10:20 interval for refreshments

SESSION 2 Chair: L. J. Butler, University of Chicago, Chicago, IL, USA

10:20 –11:00 R3: M. Brouard, University of Oxford, Oxford, United Kingdom The Stereodynamics of Photon-initiated Reaction

11:00 – 11:40 R4: F. J. Aoiz, Universidad Complutense de Madrid, Madrid, Spain Photodissociation Dynamics of Polyatomic Molecules Containing Sulfur: an Experimental Study

11:40 – 12:20 R5: C.-K. Ni, IAMS, Academia Sinica, Taipei, Taiwan Photodissociation of Simple Aromatic Molecules Studied by Multimass Ion Imaging Techniques

12:30 – 13:00 Box Lunch

13:10 – 17:30 Conference Tour to the National Palace Museum

(depart at 13:10 from the front entrance of the Grand Hotel)

18:30 – 21:30 Symposium Banquet

(12F, Skylounge) Banquet speaker: Jon T. Hougen, NIST, Gaithersburg, MD, USA

10 Friday, 30 July, 2004

SESSION 1 Chair: D. J. Nesbitt, University of Colorado, Boulder, CO, USA

8:30 – 9:10 F1: M. C. Heaven, Emory University, Atlanta, GA, USA Spectroscopy and Dynamics of NH Radical Complexes

9:10 – 9:50 F2: J. M. Hutson, University of Durham, Durham, United Kingdom Molecules in Cold Atomic Gases: How do They Interact?

9:50 – 10:20 interval for refreshments

SESSION 2 Chair: A. J. Merer, Univ. of British Columbia, Vancouver, B.C., Canada

10:20 –11:00 F3: T. C. Steimle, Arizona State University, Tempe, AZ, USA Optical Stark and Zeeman Spectroscopy of Transition Metal Containing Radicals

11:00 – 11:40 F4: Y.-C. Hsu, IAMS, Academia Sinica & National Taiwan University, Taipei, Taiwan

The Bending Vibrational Levels of C3-Rare-Gas Atom Complexes and + C2H2

11:40 – 12:20 F5: J. P. Maier, University of Basel, Basel, Switzerland Electronic Spectra of Carbon Chains and their Relevance to Astrophysics

12:30 – 13:50 Lunch (Fu-Chuan Room, B1F)

14:00 Farewell

Lab Tour to Hsinchu 14:00 – 22:30 (depart at 14:00 from the front entrance of the Grand Hotel)

11 List of Contributed Posters

Monday Evening, 26 July, 2004

No. Authors and Title

A1-01 Laperle, Christopher M.; Mann, Jennifer E.; Continetti, Robert E.

Three-Body Dissociation Dynamics of the Low-Lying Rydberg States of H3 A1-02 Lin, Jim J.; Perri, Mark J.; Van Wyngarden, Annalise L.; Boering, Kristie A.; Lee, Yuan T. Reaction Dynamics of Isotope Exchange Reaction of Singlet Oxygen Atom with Carbon Dioxide Molecule: A Crossed Molecular Beam Study A1-03 Tseng, Chien-Ming; Dyakov, Yuri A.; Huang, Cheng-Liang; Mebel, Alexander M.; Lin, Sheng Hsien; Lee, Yuan T.; Ni, Chi-Kung Photoisomerization and Photodissociation of Aniline and 4-Methylpyridine A1-04 Zhou, Weidong; Yuan, Yan; Zhang, Jingsong H-atom Elimination of n-Propyl and iso-Propyl Radicals: A Photodissociation Study A1-05 Lee, Shih-Huang; Lee, Yuan T. Studies of Photodissociation Dynamics Using Selective Photoionization A1-06 Zhang, Bailin; Shiu, Weicheng; Lin, Jim J.; Liu, Kopin 0 0 Imaging the Mode-Correlation of Product Pairs: OH + CD4 → CD3 (00 Q, 22 Q) + HOD(ν1 ν2 0) A1-07 Dyakov, Yuri A.; Mebel, Alexander M.; Lin, S. H.; Lee, Yuan T.; Ni, Chi-Kung Photodissociation of 4-Picoline, Aniline and Pyridine: Ab Initio and RRKM Study A1-08 Lee, Yin-Yu; Dung, Tzan-Yi; Lee, Shih-Huang; Pan, Wan-Chun; Chen, I-Chia; Lin, Jr-Min; Yang, Xueming; Lee, Yuan T.

Isomeric Species CH2SH and CH3S Formation from Photodissociation of Methanethiol at 157 nm A1-09 Wu, Chia-Yan; Wu, Yu-Jong; Lee, Yuan-Pern

Photodissociation of Fluorobenzene (C6H5F) at 193 nm Monitored with Time-resolved Fourier-transform Infrared Emission Spectroscopy A1-10 Chen, Wei-Kan; Ho, Jr-Wei; Cheng, Po-Yuan

Ultrafast Photodissociation Dynamics of Acetone S2 State at 195 nm A1-11 Castillo, J. F.; Aoiz, F. J.; Banares, L.; Vazquez, S.; Martinez-Nuñéz, E.; Fernandez-Ramos, A.

Quasiclassical Trajectory Studies of the F + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

12

A1-12 Eskola, Arkke; Seetula, Jorma; Timonen, Raimo Kinetics of the Reactions of Methyl Radical with HCl and DCl at Temperatures 188 – 500 K: Tunneling A1-13 Tseng, S. Y.; Huang, C. L.; Wang, T. Y.; Wang, N. S.; Xu, Z. F.; Lin, M. C. Kinetics of the NCN + NO Reaction A1-14 Wu, Di; Wang, Bing-Qiang; Li, Zhi-Ru; Hao, Xi-Yun; Li, Ru-Jiao; Sun, Chia-Chung

Single-electron Hydrogen Bonds in the Methyl Radical Complexes H3C⋅⋅⋅HF and H3C⋅⋅⋅HCCH: an ab initio Study A1-15 Hela, P. G.; Shih, H.-T.; Cheng, C.-H.; Chen, I-C. Dynamics of Photoluminescence in Bistriphenylene A1-16 Chang, Chih-Wei; Diau, Eric Wei-Guang; Chang, I-Jy

Ultrafast Interfacial Electron Transfer Dynamics of the TiO2 Nanostructures Functionalized by the Ru2+ Complexes A1-17 Hancock, G.; Morrison, M.; Saunders, M. Time Resolved FTIR Emission Studies of Molecular Dynamics A2-01 Katoh, Kaoru; Sumiyoshi, Yoshihiro; Ueno, Taketoshi; Endo, Yasuki Fourier-Transform Microwave Spectroscopy of CCCl and CCCCCl A2-02 Kobayashi, Kaori; Saito, Shuji Isotope Study of the CCO Radical in its 3Σ- Ground State by Microwave Spectroscopy A2-03 Lin, Chia-Shih; Chang, Wei-Zhong; Hsu, Hui-Ju; Chang, Bor-Chen New Dispersed Fluorescence Spectra of Simple Halocarbenes in a Discharge Supersonic Free Jet Expansion A2-04 Radi, Peter P.; Tulej, Marek; Knopp, Gregor; Beaud, Paul; Gerber, Thomas

Double-Resonance Spectroscopy on HCO and H2CO by Two-Color Resonant Four-Wave Mixing A2-05 Fink, E. H.; Ramsay, D. A.

Near Infrared Emission Spectra of HO2 and DO2 A2-06 Evertsen, R.; Staicu, A.; van Oijen, J. A.; Dam, N. J.; de Goey, L. P. H.; ter Meulen, J. J.

Cavity Ring Down Spectroscopy of CH, CH2, HCO and H2CO in a Premixed Flat Flame at both Atmospheric and Sub-atmospheric Pressure A2-07 Yurchenko, Sergei N.; Carvajal, Miguel; Jensen, Per; Lin, Hai; Thiel, Walter

Rotation-vibration Motion of Pyramidal XY3 Molecules Described in the Eckart Frame: Theory and Application to NH3 A2-08 Chen, Kuo-mei

Resonance-enhanced Multiphoton Ionization Spectroscopy of CH3 and CD3. Two-photon Absorption Selection Rules and Rotational Line Strengths of the v3- and v4-Active Vibronic Transitions

13 A2-09 Shayesteh, Alireza; Appadoo, Dominique R. T.; Gordon, Iouli; Bernath, Peter F.

The Vibration-Rotation Emission Spectra of Gaseous ZnH2 and ZnD2 A2-10 Balfour, Walter J.; Brown, John M.; Wallace, Lloyd Identification and Characterization of Two New Electronic Transitions of the FeH Radical in the Infrared A2-11 Ashworth, Stephen H.; Varberg, Thomas D.; Hodges, Philip J.; Brown, John M.

Detection of the Electronic Spectra of FeCl2 and CoCl2 in the Gas Phase A2-12 Merer, A. J.; Peers, J. R. D.; Rixon, S. J. Free Radicals in the Reaction Products of Zr with Methane: the Electronic Spectra of ZrC and ZrCH A2-13 Tang, Sheunn-Jiun; Chou, Yung-Ching; Lin, Jim Jer-Min; Hsu, Yen-Chu The Bending Vibrational Levels of Acetylene Cation: A Case Study of the Renner-Teller Effects with Two Degenerate Bending Vibrations A2-14 Yoshida, K.; Kanamori, H. High Resolution Spectroscopic Studies of Vibrational States in the Triplet Potential of Acetylene A2-15 Lin, I-Feng; Kurniawan, Fendi; Chiang, Su-Yu

Experimental and Theoretical Studies on Rydberg States of H2CS in the Region 130-220 nm A2-16 Jacox, Marilyn E.; Thompson, Warren E.

Infrared Spectra of Neutral and Ionic SO2H2 Species Trapped in Solid Neon A2-17 Jochnowitz, Evan B.; Zhang, Xu; Nimlos, Mark R.; Varne, Mychel Elizabeth; Stanton, John F.; Ellison, G. Barney Polarized IR Spectrum of Matrix-Isolated Propargyl Radicals and Detection of HC≡CH-CH2OO A2-18 Cardenas, R.; Bates, S. A.; Robbins, D. L.; Rittby, C. M. L.; Graham, W. R. M. Recent Progress in FTIR and DFT Studies on the Vibrational Spectra and Structures of Group IV Clusters A2-19 Delaney, Cailin; Clar, Justin; Cohen, Jodi; Abrash, Samuel A. Photochemistry of HI-Allene Complexes in Argon Matrices A2-20 van de Meerakker, S. Y. T.; Vanhaecke, N.; Meijer, G. Decelerating OH and NH Radical Beams A2-21 Hu, Shui-Ming; Liu, An-Wen; He, Sheng-Gui; Zheng, Jing-Jing; Lin, Hai; Zhu, Qing-Shi Inter-bonds Crossing Dipole Moment and Stretching Vibrational Bands Intersities of the Group V Hydrides

14 Tuesday Evening, 27 July, 2004

No. Authors and Title

B1-01 Capozza, G.; Leonori, F.; Segoloni, E.; Balucani, N.; Stranges, D.; Volpi, G. G.; Casavecchia, P. 3 Crossed Molecular Beam Studies of Radical-radical Reactions: O( P) + C3H5 (Allyl) B1-02 Balucani, N.; Capozza, G.; Segoloni, E.; Cartechini, L.; Bobbenkamp, R.; Casavecchia, P.; Bañares, L.; Aoiz, F. J.; Honvault, P.; Bussery-Honvault, B.; Launay, J.-M. The Dynamics of Prototype Insertion Reactions: Crossed Beam Experiments versus Quantum and Quasiclassical Trajectory Scattering Calculations on Ab 1 2 Initio Potential Energy Surfaces for C( D) + H2 and N( D) + H2 B1-03 Lin, Ming-Fu; Dyakov, Yuri A.; Lin, Sheng-Hsien; Lee, Yuan T.; Ni, Chi-Kung

Photodissociation Dynamics of Pyridine and C6HxF6-x (x = 1~4) at 193 nm B1-04 Zhou, Weidong; Yuan, Yan; Zhang, Jingsong State-to-state Photodissociation Dynamics of OH Radical via the A2Σ+ State and 3 Fine-structure Distributions of the O( PJ) Product B1-05 McCunn, L. R.; Miller, J. L.; Krisch, M. J.; Liu, Y.; Butler, L. J.; Shu, J. Molecular Beam Studies of the Photolysis of 2-Chloro-2-butene and the Subsequent Dissociation of the 2-Buten-2-yl Radical B1-06 Shiu, Vincent W. C.; Lin, Jim J.; Liu, Kopin; Wu, Malcom; Parker, David H. Threshold is More Exciting: Seeing Reactive Resonance in a Polyatomic Reaction B1-07 Martínez-Núñez, Emilio; Marques, Jorge M. C.; Vázquez, Saulo A. Dissociation of the Methanethiol Radical Cation Induced by Collisions with Ar Atoms: An Investigation by Quasiclassical Trajectories B1-08 Obernhuber, Thorsten; Kensy, Uwe; Dick, Bernhard The Photodissociation Dynamics of t-Butylnitrite Initiated by Excitation to the S2 Electronic State B1-09 Yang, Sheng-Kai; Chen, Hui-Fen; Liu, Suet-Yi; Wu, Chia-Yan; Lee, Yuan-Pern Photolysis of 2-Fluorotoluene at 193 nm: Internal Energy of HF Determined with Time-resolved Fourier-transform Infrared Emission Spectroscopy B1-10 Cireasa, D. R.; Moise, A.; ter Meulen, J. J. Inelastic State-to-state Scattering of Oriented OH by HCl B1-11 Castillo, J. F.; Aoiz, F. J.; Banares, L.

Quasiclassical Trajectory Studies of the Cl + CH4 Reaction Using an Ab Initio Potential Energy Surface Constructed by Interpolation

15

B1-12 Pimentel, André S.; Nesbitt, Fred L.; Payne, Walter A.; Cody, Regina J.

Planetary Chemistry of C2H5 Radicals: Rate Constant for the CH3 + C2H5 Reaction at Low Temperatures and Pressures B1-13 Chou, Sheng-Lung; Lee, Yuan-Pern; Lin, Ming-Chang 3 Experimental Studies of the Rate Coefficients of the Reaction O( P) + CH3OH at High Temperatures B1-14 Li, Zhi-Ru; Wu, Di; Li, Ru-Jiao; Hao, Xi-Yun; Wang, Bing-Qiang; Sun, Chia-Chung

Electron Donor-Acceptor Bonds in the Methyl Radical Complexes H3C-BH3, H3C-AlH3 and H3C-BF3: an ab initio Study B1-15 Liu, Kuan Lin; Cheng, Chao Han; Tang, Kuo-Chun; Chen, I-Chia Rapid Intersystem Crossing in Highly Phosphorescent Iridium Complexes B1-16 Luo, Liyang; Chiang, Chia-Chen; Diau, Eric Wei-Guang; Lin, Ching-Yao

Ultrafast Electron Transfer and Energy Transfer Dynamics of Porphyrin- TiO2 Nanostructures B1-17 Yin, Hong-Ming; Sun, Ju-Long; Cong, Shu-Lin; Han, Ke-Li; He, Guo-Zhong

The Internal Energy Distribution and Alignment Properties of the CH3O (X) Fragment by the Photodissociation of CH3ONO at 355 nm B2-01 Suma, Kohsuke; Sumiyoshi, Yoshihiro; Endo, Yasuki Fourier-transform Microwave Spectroscopy and FTMW-millimeter-wave Double Resonance Spectroscopy of XOO (X = Cl, Br) Radicals B2-02 Han, Huei-Lin; Chu, Li-Kang; Lee, Yuan-Pern Detection of Infrared Absorption of Gaseous ClCS Using Time-resolved Fourier-transform Spectroscopy B2-03 Fan, Haiyan; Ionescu, Ionela; Annesley, Chris; Xin, Ju; Reid, Scott A. On the Renner-Teller Effect and Barriers to Linearity and Dissociation in HCF(Ã1 A") B2-04 Colin, Reginald; Liu, Ching-Ping; Lee, Yuan-Pern Detection of Predissociated Levels of the SO B 3Σ- State using Degenerate Four-wave Mixing Spectroscopy B2-05 Elliott, N. L.; Fitzpatrick, J. A. J.; Chekhlov, O. V.; Ashworth, S. H.; Western, C. M. Electronic Structure from High Resolution Spectroscopy B2-06 Dagdigian, Paul J.; Nizamov, Boris; Teslja, Alexey

Cavity Ring-Down Spectroscopy of Polyatomic Transient Intermediates: H2CN and H2CNH B2-07 Pollack, Ilana B.; Konen, Ian M.; Li, Eunice X. J.; Lester, Marsha I. Significant OH Radical Reactions in the Atmosphere: A New View

16

B2-08 Muramoto, Yasuhiko; Ishikawa, Haruki; Mikami, Naohiko ~ 1 First Observation of the B ( A1) State of SiH2 and SiD2 Radicals by the OODR Spectroscopy B2-09 Bernath, P.; Bauschlicher, C. W.; Dulick, M.; Ram, R. S.; Burrows, A. Metal Hydrides in Astronomy B2-10 O'Brien, Leah C.; Hardimon, Sarah Fourier Transform Spectroscopy of Gold Oxide, AuO B2-11 Balfour, Walter J.; Li, Runhua; Jensen, Roy H.; Shephard, Scott A.; Adam, Allan G. The First Observation of the Rhodium Monofluoride Molecule Jet-cooled Laser Spectroscopic Studies B2-12 Miller, Terry A. Spectroscopy of Free Radicals in Hydrocarbon Oxidation B2-13 Chou, Yung-Ching; Chen, I-Chia; Hougen, Jon T. Anomalous Splittings of Torsional Sublevels Induced by the Aldehyde Inversion Motion in the S1 State of Acetaldehyde B2-14 Lee, P. C.; Yang, J. C.; Nee, J. B.

Absorption Spectra of O2 and NO in 105-200 nm Wavelength Region Measured by using a Supersonic Jet B2-15 Willitsch, Stefan; Innocenti, Fabrizio; Dyke, John M.; Merkt, Frédéric Rovibronic Energy Level Structure of the Two Lowest Electronic States of the Ozone Cation B2-16 Lo, Wen-Jui; Chen, Hui-Fen; Chou, Po-Han; Lee, Yuan-Pern

Isomers of OCS2: IR Absorption Spectra of OSCS in Solid Argon B2-17 Zhang, Xu; Kato, Shuji; Bierbaum, Veronica M.; Ellison, G. Barney Gas-Phase Reactions of Organic Radicals and Diradicals with Ions B2-18 Larsson, M.; McCall, B. J.; Huneycutt, A. J.; Saykally, R. J.; Geballe, T. R.; Djurić, N.; Dunn, G. H.; Semaniak, J.; Novotny, O.; Al-Khalili, A.; Ehlerding, A.; Hellberg, F.; Kalhouri, S.; Neau, A.; Paál, A.; Thomas, R.; Österdahl, F. + H3 Dissociative Recombination and the Cosmic-Ray Ionisation Rate towards ζ Persei B2-19 Oguchi, T.; Hattori, T.; Matsui, H. The Reaction Mechanism of O(1D) with Ethylene: the Product Yield Measurements of OH, CH2CHO and H atom B2-20 Geppert, W. D.; Thomas, R.; Ehlerding, A.; Hellberg, F.; Österdahl, F.; Millar, T. J.; Semaniak, J.; af Ugglas, M.; Djuric, N.; Larsson, M. Dissociative Recombination of Astrophysically Important Isoelectronic Ions B2-21 Peterka, Darcy S.; Kim, Jeong Hyun; Wang, Chia C.; Ahmed, Musahid; Neumark, Daniel M. Photoelectron Spectroscopy of Nitric Oxide Doped in Helium Droplets

17 Wednesday Afternoon, 28 July, 2004

No. Authors and Title

C1-01 Capozza, G.; Leonori, F.; Segoloni, E.; Volpi, G. G.; Casavecchia, P. 3 Dynamics of HCCO and CH2 Radical Formation from the Reaction O( P) + C2H2 in Crossed Beams using Soft Electron Impact Ionization for Product Detection C1-02 Capozza, G.; Segoloni, E.; Volpi, G. G.; Casavecchia, P. Towards the "Universal" Product Detection in Crossed Beam Reactive Scattering Experiments using Soft Electron Impact Ionization: Dynamics of Vynoxy, Acetyl, Methyl, Formyl, and Methylene Radicals and Ketene Formation 3 from the Reaction O( P) + C2H4 C1-03 Liu, Chen-Lin; Hsu, Hsu Chen; Ni, Chi-Kung + Photodissociation of I2 Studied by Velocity Map Imaging C1-04 Higashiyama, Tomohiko; Ishida, Masayuki; Honma, Kenji 2 3 − 2 3 Dynamics of Reaction, Y( D3/2, 5/2) + O2(X Σ g) → YO(A Π) + O( PJ), Studied by Crossed Beam-chemiluminescence Technique C1-05 Miller, J. L.; McCunn, L. R.; Krisch, M. J.; Butler, L. J.; Shu, J. Molecular Beam Studies of the Dissociation and Isomerization of Radical Isomers: The Influence of the Electronic Wavefunction in the Dissociation Dynamics of Vinoxy Radicals C1-06 Chang, Chushuan; Luo, Chu-Yung; Liu, Kopin Mode- and State-selected Photodissociation of OCS+ by Time-sliced Velocity Mapping Image Technique C1-07 Martínez-Núñez, Emilio; Vázquez, Saulo A.

Quasiclassical Trajectory Study of the 193 nm Photodissociation of CF2CHCl C1-08 Fujimura, Yo; Tamada, Hisashi; Imai, Yoshiyuki; Mitsutani, Kazuya; Kajimoto, Okitsugu 1 Reinvestigation of O( D)+H2O Reaction: Examination of the Contribution of Excited States C1-09 Bahou, Mohammed; Lee, Yuan-Pern Photodissociation Dynamics Investigated with a Pulsed Slit-jet and Time-resolved Fourier-transform Spectroscopy C1-10 Lee, Sheng-Jui; Chen, I-Chia Ab Initio Studies for Dissociation Pathway and Isomerization of Crotonaldehyde C1-11 Ho, Jr-Wei; Yang, Chia-Ming; Lai, Ta-Jen; Cheng, Po-Yuan The Use of Ultrafast Photodissociation as a Probe for Studies of Electronic Energy Transfer Dynamics

18

C1-12 Oum, Kawon; Sekiguchi, Kentaro; Luther, Klaus The Role of Radical-Molecule Complexes in the Recombination Kinetics of Benzyl Radicals C1-13 Alam, M. S.; Rao, B. S. M.; Janata, E. Reactions of •OH and H• with Aliphatic Alcohols: A Pulse Radiolysis Study C1-14 Cheng, Mu-Jeng; Chu, San-Yan

Substituent Effect on Structure and Bonding of Bertrand Diradical (X2P)2(BY)2 C1-15 Guss, Joseph; Kable Scott

Characterisation of the CCl2 Ã State C1-16 Kumae, Takashi; Arakawa, Hatsuko Assessment of Training Effects on Levels of Serum Total Anti-oxidative Activity in Matured Rats using Luminol-dependent Chemiluminescence C1-17 Dong, Feng; Whitney, Erin; Zolot, Alex; Deskevich, Mike; Nesbitt, David J. High Resolution Spectroscopy and Reaction Dynamics of Free Radicals C2-01 Katoh, Kaoru; Sumiyoshi, Yoshihiro; Endo, Yasuki; Hirota, Eizi

FTMW and FTMW-MMW Double Resonance Spectroscopy of the CH3OO Radical C2-02 Juances-Marcos, Juan Carlos; Althorpe, Stuart C. Geometric Phase and the Hydrogen-Exchange Reaction C2-03 Fan, Haiyan; Ionescu, Ionela; Annesley, Chris; Xin, Ju; Reid, Scott A. Polarization Quantum Beat Spectroscopy of HCF(Ã1A"): 19F and 1H Hyperfine Structure, Zeeman Effect, and Singlet-triplet Interactions C2-04 Liu, Ching-Ping; Reid, Scott A.; Lee, Yuan-Pern Two-color Resonant Four-wave Mixing Spectroscopy of Highly Predissociated 2 Levels in the à A1 State of CH3S C2-05 Ahmed, K.; Balint-Kurti, G. G.; Western, C. M.

Exploring the Potential Energy Surfaces of C3 C2-06 Zhang, Guiqiu; Chen, Kan-Sen; Merer, Anthony J.; Hsu, Yen-Chu; Chen, Wei-Jan; Sadasivan, Shaji; Liao, Yean-An; Kung, A. H. 1 Perturbations in the à Πu, 000 Level of C3 C2-07 Marshall, Mark D.; Greenslade, Margaret E.; Davey, James B.; Lester, Marsha I. Partial Quenching of Orbital Angular Momentum in the OH-Acetylene Complex C2-08 Fujii, Asuka; Miyazaki, Mitsuhiko; Ebata, Takayuki; Mikami, Naohiko Infrared Spectroscopy of Large-sized Protonated Water Cluster Cations: Development of the 3-Dimensional Hydrogen Bond Network with Cluster Size C2-09 Luh, Wei-Tzou Electronically-excited Singlet States of LiH

19 C2-10 O'Brien, Leah C.; O'Brien, James J. Intracavity Laser Spectroscopy of NiH C2-11 Jakubek, Zygmunt J.; Nakhate, Sanjay; Simard, Benoit; Zachwieja, Mirek

Spectroscopy of Si+NH3 and Si-PH3 Reaction Products: Rovibronic Structure of the Ground Electronic States of SiNSi and PH2 C2-12 Varberg, Thomas D.; Le Roy, Robert J. Isotope Dependence and Born-Oppenheimer Breakdown in Mid- and Far-Infrared Spectra of Cadmium Hydride C2-13 Baek, Dae Youl; Wang, Jinguo; Doi, Atsushi; Kasahara, Shunji; Baba, Masaaki; Katô, Hajime Doppler-free Two-photon Excitation Spectroscopy and the Zeeman Effect of the 1 1 1 1 10 140 Band of the S1 B2u←S0 A1g Transition of Benzene-d6 C2-14 Huang, Cheng-Liang; Liu, Chen-Lin; Ni, Chi-Kung; Hougen, Jon T.

Electronic Spectra of Molecules with Two C3v Internal Rotors: Torsional 1 1 Analysis of the A Au – X Ag LIF Spectrum of Biacetyl C2-15 Willitsch, Stefan; Dyke, John M.; Merkt, Frédéric

Rotationally Resolved Photoelectron Spectrum of NH2 and ND2: Rovibrational ~ + 1 ~ + 3 Energy Level Structure of the a A1 and X B1 States C2-16 Wu, Yu-Jong; Chou, Chun-Pang; Lee, Yuan-Pern

Isomers of CNO2: Infrared Absorption of ONCO in Solid Neon C2-17 Chou, Chun-Pang; Wu, Yu-Jong; Lee, Yuan-Pern

IR Spectroscopy of Ge(NO) and Ge(NO)2 Isolated in Solid Argon C2-18 Ehlerding, A.; Geppert, W.; Zhaunerchyk, V.; Hellberg, F.; Thomas, R.; Arnold, S. T.; Viggiano, A. A.; Semaniak, J.; Österdahl, F.; af Ugglas, M.; Larsson, M. Dissociative Recombination of Hydrocarbon Ions C2-19 Thomas, R. D.; Ehlerding, A.; Geppert, W.; Hellberg, F.; Larsson, M.; Rosen, S.; Zhaunerchyk, V.; Bahati, E.; Bannister, M. E.; Vane, C. R.; Petrignani, A.; van der Zande, W. J.; Andersson, P.; Pettersson, J. B. C. The Effect of Bonding on the Fragmentation of Small Systems C2-20 Murty, V.; Madhurima, V. Spectroscopic Studies on Some Indian Plants and Herbs-Free Radical Scavenging Action C2-21 Chen, Chun-Cing; Wu, Hsing-Chen; Tseng, Chien-Ming; Yang, Yi-Han; Chen, Yit-Tsong; One- and Two-photon Excitation Vibronic Spectra of 2-methylallyl Radical at 4.6-5.6 V

20 Assignments of Poster Boards

21 Maps of the Ground-Level of the Grand Hotel

22 Floor Plans of 12F, 10F, and B1F

23 Trails near the Grand Hotel

Distance: 5.6 km Time: 30 to 50 min Caution: This trail has several sections of steep rises. You should be physically fit to make a round trip.

24 TOUR PROGRAMME

Half-day Tours 1. Taipei City Tour (July 26, Monday morning, 8:30 AM) Duration: 3 h Adult fare: NT$700 Children's fare: NT$600 Symposium rate: US$15 Tour stops: Presidential Office (pass nearby), Chiang Kai-Shek Memorial Hall, Martyr's Shrine, Chinese Temple, Handicraft Center

2. Folk Art Tour (July 26, Monday afternoon, 1:30 PM) Duration: 4 h Adult fare: NT$900 Children's fare: NT$700 Symposium rate: US$20 Tour stops: Sanhsia Tsushih Temple, Old Street in Sanhsia, Yingko's Pottery Factory & Showroom, Pottery Street in Yingko

3. Cultural Tour (July 27, Tuesday morning, 8:30 AM) Duration: 3 h Adult fare: NT$1,200 Children's fare: NT$1,200 Symposium rate: US$30 Tour Stops: Lungshan Temple, Pao-an Temple, National Taiwan Junior College of Performing Arts (Chinese Opera Performance)

4. Wulai Aboriginal Village Tour (July 27, Tuesday afternoon, 1:30 PM) Duration: 4 h Adult fare: NT$800 Children's fare: NT$650 Symposium rate: US$18 Tour stops: Push-car Ride, Wulai Waterfall, Aboriginal Folk Dance, Swallow Lake (pass nearby), Chieftain Statue

5. Yangmingshan National Park & Hot-Spring Tour (July 28, Wednesday morning, 8:00 AM) Duration: 4 h Adult fare: NT$1,200 Children's fare: NT$1,000 Symposium rate: US$30 Tour Stops: Yangmingshan National Park, Hot-spring Bath

6. Chiufen Village & Northeast Coast Tour (July 28, Wednesday afternoon, 1:30 PM) Duration: 4 h Adult fare: NT$1,000 Children's fare: NT$800 Symposium rate: US$24 Tour Stops: Chiufen Village, Chinkfuashih Village (pass nearby), Pitou Cape, Nanya Rock Formations, Bay of Two Colors

7. Northern Coast Tour (July 29, Thursday morning, 8:30 AM) Duration: 4 h Adult fare: NT$800 Children's fare: NT$650 Symposium rate: US$18 Tour stops: Keelung City, Keelung Harbour, Buddha Statue, Yehliu Park, Queen's Head

25 Full-day Tour

8. Taroko (Marble) Gorge Tour (July 27, Tuesday, 6:30 AM) Adult fare: NT$4,500 Children's fare: NT$3,700 Symposium rate: US$120 Passport needed for enplaning. Round-trip airfare and lunch included. Itinerary: pick-up from hotel → transfer to Sungshan Domestic Airport → arrive at Hualien → by bus to Taroko Gorge Gateway → Enternal-Spring Shrine → Swallow Caves → Tunnel of Nine Turns → Tienhsiang Lodge → Marble Factory → Chi Hsin Beach → Hualien Stone Sculptural Park → enplane for Taipei → transfer to hotel

Post-Conference Tours, two days and one night (July 31−Aug. 1, Saturday−Sunday)

9. East Cost & Taroko Gorge National Park (July 31, Saturday morning, 6:30 AM) an extended version of Tour 8. Adult fare: NT$7,200 Children's fare: NT$5,800 Symposium rate: US$200 ∗ NT$800 extra for single room ∗All inclusive except meals

Itinerary: 1st day: pick-up from hotel → transfer to Sungshan Domestic Airport → arrive at Hualien → by bus to Taroko Gorge Gateway → Enternal-Spring Shrine → Swallow Caves → Tunnel of Nine Turns → Tienhsiang Lodge → Marble factory → Chi Hsing Beach → Hualien Stone Sculptural Park → Hualien (overnight at Hualien) 2nd day: pick-up from hotel → by bus to East Coast → Pachi Scenic Lookout → Stone steps → Caves of the Eight Immortals → Stone Umbrella → Sanhsientai → East Rift Valley → Hualien airport → Sungshan Domestic Airport (arrival time at Taipei ~17:30)

10. Sun Moon Lake, Puli & Lukang Tour (July 31, Saturday morning, 8:30 AM) Adult fare: NT$4,800 Children's fare: NT$3,900 Symposium rate: US$135 ∗ NT$800 extra for single room ∗All inclusive except meals

Itinerary: 1st day: pick-up from hotel→ by bus to Nantou→Sun Moon Lake→ Lake Bus Tour (Wenwu Temple-Tehua Vellage→ Tse-en Pagoda-Holy Monk Shrine)→ Puli (a cultural & artistic heaven)→ Taichung City (Overnight at Taichung City) 2nd day: Taichung City→ Lukang historical and cultural town→ by train or bus to Taipei (arrival time at Taipei ~5:30 PM)

26 General Information TRANSPORTATION

Grand Hotel Shuttle Bus Service The Grand Hotel provides a free shuttle service to the city every 20~30 minutes from 6:30 to 22:00. The shuttle departs at the main entrance outside the lobby and stops at the Taiwan Bus Corp. bus stop and Yuanshan MRT station for convenient transfer to public transportation. You can also take the shuttle bus at these two locations to return to the Grand Hotel. Current schedule is as follows:

06:30 07:00 07:30 08:00 08:20 08:40 09:00 09:30 10:00 10:30 11:00 11:20 11:40 12:00 12:20 12:40 13:00 13:30 14:00 14:30 15:00 15:20 15:40 16:00 16:20 16:40 17:00 17:20 17:40 18:00 18:20 18:40 19:00 19:20 19:40 20:00 20:20 20:40 21:00 21:20 21:40 22:00

Metro Rapid Transit System in Taipei If you would like to explore and to experience the true face of Taipei by yourself, the most economical and logical way for you is to use the Metro Rapid Transit System (MRT). The Taipei MRT system is well indicated with English signs. The "Taipei MRT Tourist Information and Map" included in the conference package serves as a useful guide for you to explore many interesting places in Taipei. Currently, five major and one branch lines are operating. They are identified by color coding: Muzha Line (brown line): Zhongshan Junior High School ⇔ Taipei Zoo Danshui Line (red line): NTU Hospital ⇔Danshui Xindian Line (green line): Xindian ⇔ NTU Hospital Zhonghe Line (orange line): Dingxi ⇔ Nanshijiao Bannan Line (blue line): Kunyang ⇔ Xinpu Xiaonanmen Branch Line (yellow green line): Hsimen ⇔ C.K.S. Memorial Hall Tickets can be purchased ticket machines in MRT stations. The fare is based on the trip distance and starts at NT$20. Those planning frequent trips can buy a one-day ticket for unlimited travel at MRT stations for NT$150. The MRT station nearest the Grand Hotel is the Yuanshan Station on the Danshui line. The Grand Hotel shuttle service provides easy access to Yuanshan Station. You should find a Taipei MRT Tourist Information and a Map in your conference bag.

27 Bus The bus system is reliable and efficient in Taipei. There are more than 300 bus lines and the major transfer hub is around Taipei Main Station. The bus system is extremely comprehensive, but can be difficult for non-Chinese readers. Destination signs on all buses are in Chinese, as are the bus schedules. Most bus drivers do not speak English. The fare for travel within one section is NT$15 per section. Most bus services operate until 23:00.

Taxi There are many taxis on the streets of Taipei. They all have a yellow color and charge by the meter for trips within the Greater Taipei area. Flag fall is NT$70 and is good for the first 1.5 km, after which the charge is NT$5 for each additional 300 m or accumulated 5-min stopping. A 5-km trip typically costs about NT$125. At night (11:00 pm−06:00 am), there is an additional 20% charge. There is no need to tip the driver. You might have to pay a little more (NT$ 30~50) to use the trunk to transport your luggage. Women passengers are advised to call a taxi company for a pick-up at night for safety reasons. Most taxi drivers can speak or read no English, so providing the destination in Chinese characters or a map is helpful. We have prepared an English-Chinese translation form for you to communicate with the drivers or to ask for directions (see p. 32).

Transportation from Taipei City to the CKS International Airport Four bus companies, Taiwan Bus Corp. (Guo Guang Bus), Free Go Express, Air Bus, and Evervoyage, operate shuttle services between CKS airport and various hotels in Taipei every 15 to 30 minutes from 6:30 am to 10:30 pm. They have two major stops in Taipei: Taipei Main Station and Sungshan Domestic Airport (in the eastern section of the city). The shuttle each way costs between NT$100 to NT$120 per passenger. Please consult the web page http://www.cksairport.gov.tw/english/transportation/taipei.htm for details.

Safety and Health

Although no responsibility can be assumed by the Symposium for a participant’s personal accidents, sickness, or property damages, we, as host of the 27th FRS symposium, shall ensure that you have a safe stay in Taiwan and shall do our utmost to assist you in any unexpected situations.

Safety Although we are proud of the low rate of crime in Taiwan, it is our responsibility to

28 remind you that burglary, pick-pockets, and robbery are not unknown. It is wise to take some precautionary measures during your stay in Taiwan, especially when you are in a crowded area or when you are alone in a remote area. Be prepared by keeping photocopies of your passport, other identification, and credit cards. You should exercise caution when crossing streets because some drivers might not respect your right of way.

Drinking Water Although the Taipei Water Department claims that tap water is drinkable, drinking unboiled tap water is not recommended. The Grand Hotel provides brand-name bottled water and boiled drinking water. Bottled water is available at most convenience stores and supermarkets.

Emergencies In case of emergency, call 110 for Police; 119 for Ambulance. No coins are required in using public telephones for these two numbers.

Health Care If you need any medical assistance during your stay in Taiwan, please contact the hotel or our local staff for immediate assistance. In case you must seek medical assistance by yourself, here is a list of hospitals in which English-speaking medical staff is available (recommended by the American Institute in Taiwan). Adventist Hospital (Taiwan): 424 Bater Rd., Sec.2, TEL 2-2771-8151 Cathay General Hospital: 280 RenAi Rd., Sec.4, TEL 2-2708-2121 Mackay Memorial Hospital: 92 ZhongShan N. Rd., Sec.2, TEL 2-2543-3535 National Taiwan University Hospital: 7 ZhongShan S. Rd., TEL 2-2397-0800 Shin Kong Wu Ho Su Memorial Hospital: 95 WenChang St., TEL 2-2833-2211 Veterans General Hospital: 201 ShiPai Rd., Sec.2, TEL 2-2871-2121

OTHERS

Currency Exchange The local currency is the New Taiwan Dollar (NTD). The current exchange rate is 1 USD ≅ 33.6 NTD. Major foreign currencies can be exchanged at CKS Airport and the Grand Hotel. Paper money is currently available in NT$100, 200, 500, 1,000 and 2,000 bills. Coins have NT$1, 5, 10, 20 and 50 denominations. Major credit cards are accepted in many shops, but traveler's cheques might be accepted only in tourist-oriented shops and hotels.

29 Public Telephone Services Public telephones are either coin-operated or card-operated. All local and domestic long-distance calls are timed. The basic charge for a local call is NT$1. Telephone cards can be purchased in most convenience stores. International Direct Dial (IDD) calls can be made by dialing the international access code 002 + country code + area code (without the preceding "0") + local number. Just dial the 8-digit numbers for calls inside Taipei (area code "02"); dial the area code ("03" for Hsinchu) plus the number if you are dialing to outside Taipei. International reverse-charge and credit-card calls can be made through dedicated telephones located at international airports and major hotels. You can also use the AT&T Direct service number 0080-1102-880 or Sprint service number 0080-1140-877 if you have an account with them. For English-speaking directory assistance in Taipei, call 106. Copy and telefax facilities are available in most convenience stores, major post offices and tourist hotels.

Shopping and VAT Refund for Tourists The 5 % sales tax is included in the sale price. Bargaining is common in traditional stores or night markets, but not in departmental stores. Foreign passengers, who on the same day and from the same authorized TRS (Tax-Refund Shopping)-labeled store purchased more than NT$3,000 (VAT inclusive) of goods eligible for VAT refund and who exit Taiwan with the goods within thirty days from the date of purchase, may claim for refund upon departure. Please proceed to the "Foreign Passenger VAT Refund Service Counter" of the Customs Service located in the airport and present the Application Form for VAT Refund, the passport (travel document or entry/exit permit), the goods to be carried out of the country and the original copy of the "uniform invoice" to the Customs officers for verification and approval. After verification, the Customs officers will issue the "VAT Refund Assessment Certificate". Present the "VAT Refund Assessment Certificate" to the designated bank located in the airport or at the seaport to receive the payment of the VAT refund. Please read the web site http://www.ntat.gov.tw/english/03information.htm or call the tourist bureau at (02)2717-3737 or 0800-011765, or the CKS service center at (03)383-4631 for details.

Tipping In general, there is no tipping in Taiwan! You do not have to tip waiters and taxi drivers. However, in some international hotels, such as the Grand Hotel, tipping hotel porters and maids will be appreciated. In some restaurants a 10 % service charge is automatically included. All other tipping is optional.

30 Telephones of Airlines Terminal 1 Terminal 2 Airline Reservation Airport Airline Reservation Airport CI China Airline (02)2715-1212 (03)3982451 AA American (02)2563-1200 (03)3983525 CO Continental (02)2719-5947 (03)3833858 AC Air Canada (02)2507-5500 (03)3982968 CX Cathay Pacific (02)2715-2333 (03)3982501 BR Eva Air (02)2501-1999 (03)3982968 EG Japan Asia 0800-065-151 (03)3982282 EL Air Nippon (02)2501-7299 (03)3982968 KE Korean Air (02)2518-2200 (03)3834106 KL KLM Asia (02)2711-4055 (03)3833034 NW Northwest (02)2772-2188 (03)3982471 SQ Singapore (02)2551-6655 (03)3983988 TG Thai Airways (02)2509-6800 (03)3834131 UA United (02)2325-8868 (03)3982781 AF Air France (02)2718-1631 DL Delta (02)2551-3656 AY Finn Air (02)2773-3266 #138 LH Lufthansa (02)2325-2295 BA British Air (02)2512-6888 LX Swiss Air (02)2507-2213 Foreign Consulates in Taiwan

ASIAN AND PACIFIC COUNTRIES Australian Commerce and Industry Office (02)8725-4100 Korean Mission in Taipei (02)2758-8320 Singapore Trade Office in Taipei (02)2772-1940 EUROPEAN COUNTRIES Belgian Trade Association, Taipei (02)2715-1215 British Trade and Cultural Office (02)2322-4242 Danish Trade Organizations' Taipei Office (02)2718-2101 Finland Trade Center (02)2722-0764 French Institute in Taipei (02)2545-6061 Deutsche Institute Taipei (02)2501-6188 Italian Economic, Trade and Cultural Promotion Office (02)2345-0320 Netherlands Trade and Investment Office (02)2713-5760 Norwegian Trade Council (02)2543-5484 Spanish Chamber of Commerce (02)2518-4901 Swedish Trade Council (02)2757-6573 Trade Office of Swiss Industries (02)2720-1001 AMERICAN COUNTRIES American Institute in Taiwan, Taipei Office (02)2709-2000 Canadian Trade Office in Taipei (02)2547-9500

31 Useful English-Chinese Translation

English Chinese Please take me to --- 請帶(載)我去---- the Grand Hotel 圓山大飯店 CKS international airport 中正國際機場 Yuanshan MRT station 圓山捷運站 the nearest MRT station 最近的捷運站 the Taipei Main (Railway/MRT) Station 台北火車站

Can you show me the way to --- ? 請問 --- 怎麼走？ the bus station 巴士站 the Grand Hotel 圓山大飯店 Yuanshan MRT station 圓山捷運站 the nearest MRT station 最近的捷運站 the Taipei Main (Railway/MRT) Station 台北火車站 the nearest convenience store 最近的便利商店

How to take MRT to Yuanshan Station? 請問往圓山的捷運怎麼搭？ Which platform for Yuanshan Station? 請問往圓山的捷運在那一個月台？ When the train reaches Yuanshan Station, please 到圓山站時，請提醒我下車。 remind me to disembark. Where shall I wait for the shuttle bus of the Grand 請問往圓山大飯店的免費交通車在 Hotel ? 那裡等？ Thank you. (Shay4 Shay0)a 謝謝。 Excuse me. (Duay4 Buh4 Chi3) 對不起。 You are welcome (Buh2 Ker4 Chi4) 不客氣。 How are you? (Nee2 How3 Mah1) 你好嗎。 How much? (Duow1 Shau3 Chien2) 多少錢。 Can you lower the price? 算便宜一點好嗎？ (Pien2 Yi2 Yi1 Di-en3 How3 Buh4 How3) Good Bye (Tsai4 Jien4) 再見 aIntonation is denoted as a superscript.

32 History of Free Radical Symposia

No. Year Location Symposium Chair(s) 1 1956 Quebec City, CANADA P. A. Giguère 2 1957 Washington, DC, USA H. P. Broida, A. M. Bass 3 1958 Sheffield, UK G. Porter 4 1959 Washington, DC, USA H. P. Broida, A. M. Bass 5 1961 Uppsala, SWEDEN S. Claesson 6 1963 Cambridge, UK B. A. Thrush 7 1965 Padua, ITALY G. Semerano 8 1967 Novosibirsk, USSR V. N. Kondratiev 9 1969 Banff, CANADA H. Gunning, D. A. Ramsay 10 1971 Lyon,FRANCE M. Peyron 11 1973 Königsee, GERMANY W. Groth 12 1976 Laguna Beach, CA, USA E. K. C. Lee, F. S. Rowland 13 1977 Lyndhurst, Hants, UK A. Carrington 14 1979 Sanda, Hyogo-ken, JAPAN Y. Morino, I. Tanaka 15 1981 Ingonish, NS, CANADA W. E. Jones 16 1983 Lauzelles-Ottignies, BELGIUM R. Colin 17 1985 Granby, Colorado, USA K. M. Evenson, R. F. Curl, H. E. Radford 18 1987 Oxford, UK J. M. Brown 19 1989 Dalian, CHINA Postponed 20 1990 Susono, Shizuoka, JAPAN H. Hirota 21 1991 Williamstown, MA, USA S. D. Colson 22 1993 Doorworth, NETHERLANDS H. ter Meulen 23 1995 Victoria, BC, CANADA A. J. Merer 24 1997 Tällberg, SWEDEN M. Larsson 25 1999 Flagstaff, AZ, USA T. A. Miller 26 2001 Assisi, ITALY P. Casavecchia 27 2004 Taipei, TAIWAN Y.-P. Lee

33 List of Participants

Abrash, Samuel A. Akimoto, Hajime Department of Chemistry Atmospheric Composition Research University of Richmond Program, Richmond, VA 23173 Frontier Research System for Global USA Change Tel: +1-804-289-8248 Yokohama, 236-0001 Fax: +1-804-287-1897 Japan [email protected] Tel: +81-45-778-5710 Fax: +81-45-778-5496 [email protected]

Alam, Mohammad Shahdo Althorpe, Stuart C. Department of Chemistry Department of Chemistry National Tsing Hua University University of Exeter Hsinchu, 30013 Exeter, EX4 4QD Taiwan UK Tel: +886-3-5714687 Tel: +44-1392-263473 Fax: +886-3-5722892 Fax: +44-1392-263434 [email protected] [email protected]

Aoiz, Francisco Javier Bahou, Mohammed Departamento de Quimica Fisica I Department of Chemistry Universidad Complutense de Madrid National Tsing Hua University Madrid, 28040 101, Sec. 2, Kuang Fu Road Spain Hsinchu, 30013 Tel: +34-913-944126 Taiwan Fax: +34-913-944135 Tel: +886-3-5715131-3421 [email protected] Fax: +886-3-5722892 [email protected]

Balfour, Rosemary Balfour, Walter J. Department of Chemistry Department of Chemistry University of Victoria University of Victoria Victoria BC, V8W 3P6 Victoria BC, V8W 3P6 Canada Canada Tel: +1-250-721-7168 Tel: +1-250-721-7168 Fax: +1-250-721-7147 Fax: +1-250-721-7147 [email protected] [email protected]

34 Bernath, Peter F. Bondybey, Vladimir E. Department of Chemistry Institute fur Physicalishe Chemie University of Waterloo Technische Universitat Munchen 200 University Avenue West Lichtebergstr. 4 Waterloo, Ontario, N2L 3G1 Garching, D-8574 Canada Germany Tel: +1-519-888-4814 Tel: +49-89-2891-3421 Fax: +1-519-746-0435 Fax: +49-89-2891-3416 [email protected] [email protected]

Brouard, Mark Brown, John M. The Physical and Theoretical Chemistry The Physical and Theoretical Chemistry Laboratory Laboratory, Department of Chemistry University of Oxford, South Parks Road University of Oxford, South Parks Road Oxford, OX1 3QZ Oxford, OX1 3QZ UK UK Tel: +44-1865-275410 Tel: +44-1865-275457 Fax: +44-1865-275410 Fax: +44-1865-275410 [email protected] [email protected]

Butler, Laurie J. Butler, Lynne M. James Franck Institute James Franck Institute 5640 S. Ellis Ave 5640 S. Ellis Ave Chicago, IL 60637 Chicago, IL 60637 USA USA Tel: +1-773-702-7206 Tel: +1-773-702-7206 Fax: + Fax: + [email protected] [email protected]

Casavecchia, Piergiorgio Castillo, Jesus F. Dipartimento di Chimica Departamento de Quimica Fisica I Universita di Perugia Universidad Complutense de Madrid Perugia, 06123 Madrid, 28040 Italy Spain Tel: +39-0755855514 Tel: +34-913-944-126 Fax: +39-0755855606 Fax: +34-913-944-135 [email protected] [email protected]

Chang, Ying-de Chang, Chih-Wei Institute of Atomic and Molecular Science, Department of Applied Chemistry Academia Sinica National Chiao Tung University P. O. Box 23-166 1001, Ta-Hsueh Rd. Taipei, 106 Hsinchu, 30010 Taiwan Taiwan Tel: +886-2-2366-8250 Tel: +886-3-5712121-56570 Fax: +886-2362-0200 Fax: +886-3-5723764 [email protected] [email protected]

35 Chang, Bor-Chen Chang, Wei-Zhong Department of Chemistry Department of Chemistry National Central University National Central University 300 Jung-Da Road 300 Jung-Da Road Chung Li, 32054 Chung Li, 32054 Taiwan Taiwan Tel: +886-3-4227151x5908 Tel: +886-3-4227151x5918 Fax: +886-3-4227664 Fax: +886-3-4227664 [email protected] [email protected]

Chang, Chushuan Chang, Huan-Cheng Institute of Atomic and Molecular Sciences, Institute of Atomic and Molecular Sciences, Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8257 Tel: +886-2-2366-8260 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Chen, Ming-Wei Chen, Chun-Cing Department of Chemistry Institute of Atomic and Molecular Science, National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5643335 Taiwan Fax: +886-3-5717553 Tel: +886-2-2366-8250 [email protected] Fax: +886-2362-0200 [email protected]

Chen, Hsueh-Ying Chen, Chia-Yi Department of Chemistry Department of Chemistry National Tsing Hua University National Central University Hsinchu, 30013 300 Jung-Da Road Taiwan Chung Li, 32054 Tel: +886-3-5715131-3423 Taiwan Fax: + Tel: +886-3-4227151-5918 [email protected] Fax: +886-3-4227664 [email protected]

Chen, Kuo-Mei Chen, Stella L. Department of Chemistry Department of Chemistry and Biochemistry, National Sun Yat-sen University University of Colorado Kaohsiung, 804 Boulder, CO 80309 Taiwan USA Tel: +886-7-525-3911 Tel: +1-303-492-5406 Fax: +886-7-525-3912 Fax: +1-303-492-5894 [email protected] [email protected]

36 Chen, Yang Chen, Kan-Sen Dept. of Chem. Phys. Institute of Atomic and Molecular Sciences, University of Science and Technology of Academia Sinica China P. O. Box 23-166 Hefei, 230026 Taipei, 106 China Taiwan Tel: +86-551-360-6619 Tel: +886-2-2366-8217 Fax: +86-551-360-7084 Fax: +886-2-2362-0200 [email protected] [email protected]

Chen, I-Chia Chen, Yit-Tsong Department of Chemistry Department of Chemistry National Tsing Hua University National Taiwan University Hsinchu, 30013 No. 1, Sec. 4, Roosevelt Road Taiwan Taipei, 106 Tel: +886-3-5715131-3339 Taiwan Fax: +886-3-5721614 Tel: +886-2-366-8238 [email protected] Fax: +886-2-2362-0200 [email protected]

Chen, Hui-Fen Chen, Wei-Kan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-3-5715131-3423 Fax: +886-3-5722892 Fax: + [email protected] [email protected]

Cheng, Mu-Jeng Cheng, Po-Yuan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3390 Tel: +886-3-573-7816 Fax: +886-3-5711082 Fax: + [email protected] [email protected]

Cheng, Chao-Han Chiang, Su-Yu Department of Chemistry National Synchrotron Radiation Research National Tsing Hua University Center Hsinchu, 30013 101, Hsin-Ann Rd. Taiwan Science-Based Industrial Park Tel: +886-3-5715131-3425 Hsinchu, 30077 Fax: +886-3-5721614 Taiwan [email protected] Tel: +886-3-5780281-7315 Fax: +886-3-5783813 [email protected]

37 Ching, Dauw-Chung Choi, Jong-Ho Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica Korea University P. O. Box 23-166 Anam-dong, Sungbuk-ku Taipei, 106 Seoul, 136-701 Taiwan Korea Tel: +886-2-2912-2437 Tel: +82-2-3290-3135 Fax: +886-2-2362-0200 Fax: +82-2-3290-3121 [email protected] [email protected]

Choi, Woosuk Chou, Chun Pang Department of Chemistry Department of Chemistry Korea University National Tsing Hua University Anam-dong, Sungbuk-ku Hsinchu, 30013 Seoul, 136-701 Taiwan Korea Tel: +886-3-5715131-3346 Tel: +82-2-3290-3135 Fax: +886-3-5722892 Fax: +82-2-3290-3121 [email protected] [email protected]

Chou, Po Han Chou, Yung-Ching Department of Chemistry Institute of Atomic and Molecular Sciences, National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5715131-3346 Taiwan Fax: +886-3-5722892 Tel: + [email protected] Fax: + [email protected]

Chou, Sheng Lung Chu, San-Yan Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-3-5715131-3390 Fax: +886-3-5722892 Fax: +886-3-5711082 [email protected] [email protected]

Chuang, Su-Ching Chung, Chao-Yu Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3345 Tel: +886-3-5715131-5407 Fax: +886-3-5722892 Fax: +886-3-5722892 [email protected] [email protected]

38 Colin, Reginald Continetti, Robert E. Laboratoire de Chimie Quantique et Department of Chemistry and Biochemistry Photophysique, CP 160/9 Univ. California, San Diego Université Libre de Bruxelles 9500 Gilman Drive 50,av. F. D. Roosevelt La Jolla, CA 92093-0340 1050 Brussels USA Belgium Tel: +1-858-534-5559 Tel: +32-2-650-2420 Fax: +1-858-534-7244 Fax: +32-2-650-4232 [email protected] [email protected]

Curl, Jonel W. Curl, Robert F. Chemistry Department MS-60 Chemistry Department MS-60 Rice University Rice University Houston, TX 77005 Houston, TX 77005 USA USA Tel: +1-713-348-4816 Tel: +1-713-348-4816 Fax: +1-713-348-5155 Fax: +1-713-348-5155 [email protected] [email protected]

Dagdigian, Paul J. Dai, Dongxu Department of Chemistry, Remsen Hall Dalian Institute of Chemical Physics Johns Hopkins University Chinese Academy of Sciences 3400 N. Charles Street 457 Zhongshan Road Baltimore, MD 21218 Dalian, 116023 USA China Tel: +1-410-516-7438 Tel: +86-411-84379360 Fax: +1-410-516-8420 Fax: +86-411-84675584 [email protected] [email protected]

Diau, Eric Wei-Guang Dyakov, YuRi Department of Applied Chemistry Institute of Atomic and Molecular Sciences, National Chiao Tung University Academia Sinica 1001, Ta-Hsueh Rd. P. O. Box 23-166 Hsinchu, 30010 Taipei, 106 Taiwan Taiwan Tel: +886-3-5131524 Tel: +886-2-2366-8272 Fax: +886-3-5723764 Fax: +886-2-2362-0200 [email protected] [email protected]

Ehlerding, Anneli Endo, Yasuki Department of Physics Department of Basic Science Stockholm University The University of Tokyo Alba Nova University Center Komaba 3-8-1, Meguro Stockholm, SE106 91 Tokyo, 153-8902 Sweden Japan Tel: +46-8-55378648 Tel: +81-3-5454-6748 Fax: +46-8-55378601 Fax: +81-3-5454-6721 [email protected] [email protected]

39 Fang, Yung-Sheng Fujii, Asuka National Synchrotron Radiation Research Department of Chemistry Center Graduate School of Science 101, Hsin-Ann Road Tohoku University Science-Based Industrial Park Sendai, 980-8578 Hsinchu, 30077 Japan Taiwan Tel: +81-22-217-6573 Tel: +886-3-5780281 Fax: +81-22-217-6785 Fax: +886-3-5783813 [email protected] [email protected]

Fujimura, Yo Geppert, Wolf D. Department of Chemistry Department of Molecular Physics Graduate School of Science Alba Nova, University of Stockholm, Kyoto University Roslagstullbacken 21 Kitashirakawa-Oiwakecho, Sakyo-ku Stockholm, S-10691 Kyoto, 606-8502 Sweden Japan Tel: +46-8-5537-8649 Tel: +81-75-753-3972 Fax: +46-8-5537-8601 Fax: +81-75-753-3974 [email protected] [email protected]

Graham, Hsueh Mei Graham, William R. M. Department of Physics and Astronomy Department of Physics and Astronomy Box 298840, TCU Box 298840, TCU Fort Worth, TX 76129 Fort Worth, TX 76129 USA USA Tel: +1-817-257-6383 Tel: +1-817-257-6383 Fax: +1-817-257-7740 Fax: +1-817-257-7740 [email protected] [email protected]

Guss, Joseph S. Halberstadt, Nadine School of Chemistry Laboratorire de Physique University of Sydney Quantique/IRSAMC, Université Paul Sabatier Sydney, NSW 2006 118 route de Narbonne Australia Toulouse, 31062 Tel: +61-2-9351-4424 France Fax: +61-2-9351-3329 Tel: +33-5-6155-6488 [email protected] Fax: +33-5-6155-6065 [email protected]

Han, Ke-Li Han, Huei-Lin Dalian Institute of Chemical Physics Department of Chemistry Chinese Academy of Sciences National Tsing Hua University P. O. Box 110-11 Hsinchu, 30013 457 Zhongshan Road Taiwan Dalian, 116023 Tel: +886-3-5715131-3346 China Fax: +886-3-5722892 Tel: +86-411-843-79293 [email protected] Fax: +86-411-846-75584 [email protected]

40 Haung, Jackson Heaven, Michael C. Department of Chemistry Department of Chemistry National Tsing Hua University Emory University Hsinchu, 30013 1515 Dickey Drive Taiwan Atlanta, GA 30322 Tel: +886-3-5715131-3423 USA Fax: + Tel: +1-404-727-6617 [email protected] Fax: +1-404-727-6586 [email protected]

Hepburn, John W. Hirota, Satoko Faculty of Science The Graduate University for Advanced The University of British Columbia, Studies #1505-6270 University Blvd. Hayama, Kanagawa 240-0193 Vancouver, BC V6T 1Z4 Japan Canada Tel: +81-468-58-1500 Tel: +1-604-822-0220 Fax: +81-468-58-1542 Fax: +1-604-822-0677 [email protected] [email protected]

Hirota, Eizi Ho, Jia-Jen The Graduate University for Advanced Department of Chemistry Studies National Taiwan Normal University Hayama, Kanagawa 240-0193 88, Sec. 4, Ting-Chow Rd. Japan Taipei, 116 Tel: +81-468-58-1500 Taiwan Fax: +81-468-58-1542 Tel: +886-2-2930-9085 [email protected] Fax: +886-2-2932-4249 [email protected]

Ho, Jr-Wei Ho, Tong-Ing Department of Chemistry Department of Chemistry National Tsing Hua University National Taiwan University Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3423 Tel: +886-2-23691801 Fax: + Fax: +886-2-23636359 [email protected] [email protected]

Honma, Kenji Hougen, Jon T. Department of Material Science Optical Technology Division, NIST Himeji Institute of Technology Gaithersburg, MD 20899-8441 3-2-1 Kohto, Kamigori USA Hyogo, 678-1297 Tel: +1-301-975-2379 Japan Fax: +1-301-975-2950 Tel: +81-791-58-0167 [email protected] Fax: +81-791-58-0132 [email protected]

41 Hsu, Hsu-Chen Hsu, Yen-Chu Institute of Atomic and Molecular Sciences, Institute of Atomic and Molecular Sciences, Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8268 Tel: +886-2-2366-8281 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Hsu, Hui-Ju Hu, Shuiming Department of Chemistry Dept. Chem. Physics National Central University Univ. of Science and Technology of China 300 Jung-Da Road Jinzhai Road, 96# Chung Li, 32054 Hefei, 230026 Taiwan China Tel: +886-3-4227151x5918 Tel: +86-551-3607460 Fax: +886-3-4227664 Fax: +86-551-3602969 [email protected] [email protected]

Hu, Helen YiaoYing Huang, Hong-Yi Department of Chemistry Institute of Atomic and Molecular Science, The University of York Academia Sinica York, YO10 5DD P. O. Box 23-166 UK Taipei, 106 Tel: +44-1904-434526 Taiwan Fax: +44-1904-434527 Tel: +886-2-2366-8289 [email protected] Fax: +886-2362-0200 [email protected]

Huang, Cheng-Liang Hung, Andy Applied Chemistry Department Department of Chemistry Chiayi University National Tsing Hua University 300, University Road Hsinchu, 30013 Chiayi, 600 Taiwan Taiwan Tel: +886-3-5715131-3423 Tel: +886-5-2717879 Fax: + Fax: +886-5-2717901 [email protected] [email protected]

Hutson, Jeremy M. Ishikawa, Haruki Department of Chemistry Department of Chemistry University of Durham Graduate School of Science Durham, DH1 3LE Tohoku University UK Aramaki-Aoba, Aoba-ku Tel: +44-191-334-2147 Sendai, 980-8578 Fax: +44-191-384-4737 Japan [email protected] Tel: +81-22-217-6573 Fax: +81-22-217-6785 [email protected]

42 Jacox, Marilyn E. Jensen, Per Mail Stop 8441 Faculty of Mathematics and Natural Optical Technology Division Sciences, Department of Chemistry National Institute of Standards and Bergische Universität Wuppertal Technology Wuppertal, D-42097 Gaithersburg, MD 20899-8441 Germany USA Tel: +49-202-439-2468 Tel: +1-301-975-2547 Fax: +49-202-439-2509 Fax: +1-301-869-5700 [email protected] [email protected]

Jones, Norma Jones, William E. Saint Mary's University Saint Mary's University Burke Building, Suite 110 Burke Building, Suite 110 Halifax NS, B3H 3C3 Halifax NS, B3H 3C3 Canada Canada Tel: +1-902-496-8169 Tel: +1-902-496-8169 Fax: +1-902-496-8772 Fax: +1-902-496-8772 [email protected] [email protected]

Kable, Scott H. Kanamori, Hideto School of Chemistry Department of Physics University of Sydney Tokyo Institute of Technology Sydney, NSW 2006 2-12-1 Ohokayama, Muguro-ku Australia Tokyo, 152-8551 Tel: +61-2-9351-2756 Japan Fax: +61-2-9351-3329 Tel: +81-3-5734-2615 [email protected] Fax: +81-3-5734-2751 [email protected]

Kato, Hajime Katoh, Kaoru Molecular Photoscience Research Centre Department of Basic Science Kobe University Graduate School of Arts and Sciences Rokkodai-cho 1-1, Nada-ku The University of Tokyo Kobe, 657-8501 Komaba 3-8-1, Meguro-ku Japan Tokyo, 153-8902 Tel: +81-78-803-5671 Japan Fax: +81-78-803-5678 Tel: +81-3-5454-6766 [email protected] Fax: +81-3-5454-6721 [email protected]

Kobayashi, Ayana Kobayashi, Tsuyoshi Graduate School of Sci. and Engine. Graduate School of Sci. and Engine. Tokyo Inst. Tech, Tokyo, Japan Tokyo Inst. Tech, Tokyo, Japan 2-12-1 Ohokayama, Muguro-ku 2-12-1 Ohokayama, Muguro-ku Tokyo, 152-8501 Tokyo, 152-8501 Japan Japan Tel: +81-3-5734-2704 Tel: +81-3-5734-2704 Fax: +81-3-5734-2751 Fax: +81-3-5734-2751 [email protected] [email protected]

43 Kobayashi, Kaori Kou, Che-lun Graduate School of Sci. and Engine. Department of Physics Tokyo Inst. Tech, Tokyo, Japan National Central University 2-12-1 Ohokayama, Muguro-ku 300, Jung Da Road Tokyo, 152-8501 Chung Li, 32054 Japan Taiwan Tel: +81-3-5734-2704 Tel: +886-3-4227151-5310 Fax: +81-3-5734-2751 Fax: + [email protected] [email protected]

Kumae, Takashi Lai, Ta-Jen Div. of Health Promotion & Exercise Department of Chemistry Natl. Inst. of Health Nutrition National Tsing Hua University 1-23-1 Toyama, Shinjuku-ku Hsinchu, 30013 Tokyo, 162-8636 Taiwan Japan Tel: +886-3-5715131-3423 Tel: +81-3-3203-8061 Fax: + Fax: +81-3-3203-1731 [email protected] [email protected]

Larsson, Mats Lee, Yin-Yu Department of Physics National Synchrotron Radiation Research Stockholm University Center AlbaNova 101, Hsin-Ann Road Stockholm, SE-10691 Science-Based Industrial Park Sweden Hsinchu, 30077 Tel: +46-8-5537-8647 Taiwan Fax: +46-8-5537-8601 Tel: +886-3-5780281-7114 [email protected] Fax: +886-3-5783813 [email protected]

Lee, Sheng-Jui Lee, Yuan-Pern Department of Chemistry Department of Applied Chemistry National Tsing Hua University National Chiao Tung University Hsinchu, 300 Hsinchu, 30010 Taiwan Taiwan Tel: +886-3-5715131-3427 Tel: +886-3-5715131-3345 Fax: +886-3-5721614 Fax: +886-3-5722892 [email protected] [email protected]

Lee, Shih-Huang Lee, Y. T. National Synchrotron Radiation Research Institute of Atomic and Molecular Sciences, Center Academia Sinica 101, Hsin-Ann Road P. O. Box 23-166 Science-Based Industrial Park Taipei, 106 Hsinchu, 30077 Taiwan Taiwan Tel: +886-2-2366-8200 Tel: +886-3-5780281 Fax: +886-2-2785-3852 Fax: +886-3-5783813 [email protected] [email protected]

44 Leone, Stephen R. Lester, Marsha I. University of California and Lawrence Department of Chemistry Berkeley National Laboratory University of Pennsylvania Department of Chemistry 231 S. 34th Street 209 Gilman Hall Philadelphia, PA 19104-4640 Berkeley, CA 94720-1460 USA USA Tel: +1-215-898-4640 Tel: +1-510-643-5467 Fax: +1-215-573-2112 Fax: +1-510-642-6262 [email protected] [email protected]

Li, Zhi-Ru Liang, Chi-Wei Institute of Theoretical Chemistry Institute of Atomic and Molecular Sciences Jilin University Academia Sinica Changchun, 130023 P. O. Box 23-166 China Taipei, 106 Tel: +86-431-8498964 Taiwan Fax: +86-431-8945942 Tel: +886-2-2246-6016 [email protected] Fax: +886-2-2362-0200 [email protected]

Lin, Ming Chang Lin, Min-Fu Department of Chemistry Institute of Atomic and Molecular Sciences Emory University Academia Sinica 1515 Dickey Drive P. O. Box 23-166 Atlanta, Georgia 30322 Taipei, 106 USA Taiwan Tel: +1-404-727-2825 Tel: +886-2-2366-8268 Fax: +1-404-727-6586 Fax: +886-2-2362-0200 [email protected] [email protected]

Lin, Jung-Lee Lin, I-Feng IAMS, Academia Sinica National Synchrotron Radiation Research P. O. Box 23-166 Center Taipei, 106 101, Hsin-Ann Road Taiwan Science-Based Industrial Park Tel: +886-2-2366-8222 Hsinchu, 30077 Fax: +886-2-2362-0200 Taiwan [email protected] Tel: +886-3-5780281 Fax: +886-3-5783805 [email protected]

Lin, Qiong Lin, King-Chuen Physical Chemistry Lab., ETH Honggerberg, Institute of Atomic and Molecular Sciences HCI E209 Academia Sinica Zurich, CH-8093 P. O. Box 23-166 Switzerland Taipei, 106 Tel: +41-1633-4391 Taiwan Fax: +41-1632-1021 Tel: +886-2-2369-0152x101 [email protected] Fax: +886-2-2362-0200 [email protected]

45 Lin, Sheng Hsien Lin, Jim J. Institute of Atomic and Molecular Sciences Institute of Atomic and Molecular Sciences Academia Sinica Academia Sinica P. O. Box 23-166 P. O. Box 23-166 Taipei, 106 Taipei, 106 Taiwan Taiwan Tel: +886-2-2366-8203 Tel: +886-2-2366-8258 Fax: +886-2-2362-4925 Fax: +886-2-2362-0200 [email protected] [email protected]

Lineberger, William Carl Liske, Christiane JILA, 440 UCB Department of Chemistry University of Colorado University of Basel Boulder, CO 80309-0440 Klingelbergstrasse 80 U. S. A. Basel, CH-4056 Tel: +1-303-492-7834 Switzerland Fax: +1-303-492-8994 Tel: +41-612673826 [email protected] Fax: +41-612673855 [email protected]

Liu, Chen-Lin Liu, Suet-Yi Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3346 Tel: +886-2-2366-8268 Fax: +886-3-5722892 Fax: +886-2-2362-0200 [email protected] [email protected]

Liu, Shilin Liu, Tsui-Yu Department of Chemical Physics Department of Chemistry University of Science & Technology of China National Tsing Hua University Hefei, 230026 Hsinchu, 30013 China Taiwan Tel: +86-551-3602323 Tel: +886-3-5715131-3339 Fax: +86-551-3607084 Fax: +886-3-5721614 [email protected] [email protected]

Liu, Kopin Liu, Ching-Ping Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-3420 Tel: +886-2-2366-8259 Fax: +886-3-5722892 Fax: +886-2-2363-0578 [email protected] [email protected]

46 Liu, Kuan-Lin Lu, Y.-J. Department of Chemistry Institute of Atomic and Molecular Sciences National Tsing Hua University Academia Sinica Hsinchu, 30013 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5715131-3427 Taiwan Fax: +886-3-5721614 Tel: +886-2-2366-8257 [email protected] Fax: +886-2-2362-0200 [email protected]

Luh, Wei-Tzou Luo, Liyang Department of Chemistry Department of Applied Chemistry National Chung Hsing University National Chiao Tung University 250, Kuo-Kuang Road 1001, Ta-Hsueh Rd. Taichung, 402 Hsinchu, 30010 Taiwan Taiwan Tel: +886-4-2285-2238 Tel: +886-3-5712121-56570 Fax: +886-4-2286-2547 Fax: +886-3-5723764 [email protected] [email protected]

Luo, Chu-Yung Luther, Klaus Institute of Atomic and Molecular Sciences Institut für Physikalische Chemie Academia Sinica der Universität Göttingen P. O. Box 23-166 Tammannstraβe 6 Taipei, 106 Göttingen, D-37077 Taiwan Germany Tel: +886-2-2366-8257 Tel: +49-551-393120 Fax: +886-2-2362-0200 Fax: +49-551-393-150 [email protected] [email protected]

Maier, John P. Martínez-Núñez, Emilio Department of Chemistry Departamento de Qijica Fisica University of Basel Facultad de Quimica Klingelbergstrasse 80 Avda das Ciencias s/n Basel, CH-4056 Santiago de Compostela, 15782 Switzerland Spain Tel: +41-612673826 Tel: +34-981-563100-14450 Fax: +41-612673855 Fax: +34-981-595012 [email protected] [email protected]

McCunn, Laura R. van de Meerakker, Bas James Franck Institute Dept. of Mole. Phys. University of Chicago Fritz-Haber-Institut der 5640 S. Ellis Ave. Max-Planck-Gesellschaft Chicago, IL 60637 Faradayweg 4-6 USA Berlin, D-14195 Tel: +1-773-702-9003 Germany Fax: + Tel: +49-30 84 1357 31 [email protected] Fax: +49-30 84 1356 03 [email protected]

47 Meijer, Gerard Merer, Anthony J. Dept. of Mole. Phys. Department of Chemistry Fritz-Haber-Institut der University of British Columbia Max-Planck-Gesellschaft 2036 Main Mall Faradayweg 4-6 Vancouver, B. C., V6T 1Z1 Berlin, D-14195 Canada Germany Tel: +1-604-822-2950 Tel: +49-30 84 1356 02 Fax: +1-604-822-2847 Fax: +49-30 84 1356-11 [email protected] [email protected]

Merkt, Frederic Miller, Barbara Physical Chemistry Lab. Department of Chemistry ETH Honggerberg, HCI Ohio State University Zurich, CH-8093 100 W. 18th Avenue Switzerland Columbus, OH 43210 Tel: +41-1-632-4367 USA Fax: +41-1-632-1021 Tel: +1-614-292-2569 [email protected] Fax: +1-614-292-1948 [email protected]

Miller, Terry A. Momose, Takamasa Department of Chemistry Division of Chemistry Ohio State University Graduate School of Science 100 W. 18th Avenue Kyoto, 606-8502 Columbus, OH 43210 Japan USA Tel: +81-75-753-4048 Tel: +1-614-292-2569 Fax: +81-75-753-4000 Fax: +1-614-292-1948 [email protected] [email protected]

Morrison, Marc D. Muller-Dethlefs, Klaus Physical and Theoretical Chemistry Department of Chemistry Laboratory The University of York University of Oxford York, YO10 5DD South Parks Road UK Oxford, OX1 3QZ Tel: +44-1904-434526 UK Fax: +44-1904-434527 Tel: +44-1865-275484 [email protected] Fax: +44-1865-275410 [email protected]

Nee, J. B. Nesbitt, David J. Department of Chemistry JILA/NIST, University of Colorado National Central University UCB 440 Chung-Li, 32054 Boulder, CO 80309-0440 Taiwan USA Tel: +886-3-422-7151x5311 Tel: +1-303-492-8857 Fax: +886-3-425-1175 Fax: +1-303-735-1424 [email protected] [email protected]

48 Neusser, Hans J. Neusser, Sebastian Physikalische Chemie Physikalische Chemie Technische Universität München Technische Universität München Lichtenbergstrasse 4 Lichtenbergstrasse 4 Garching, D-85748 Garching, D-85748 Germany Germany Tel: +49-89-289-13388 Tel: +49-89-289-13388 Fax: +49-89-289-13412 Fax: +49-89-289-13412 [email protected] [email protected]

Ni, Chi-Kung O'Brien, James J. Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica University of Missouri P. O. Box 23-166 8001 Natural Bridge Rd. Taipei, 106 St. Louis, MO 63121-4499 Taiwan USA Tel: +886-2-2366-8268 Tel: +1-314-516-5717 Fax: +886-2-2362-0200 Fax: +1-314-516-5342 [email protected] [email protected]

O'Brien, Leah C. Ogilvie, John F. Department of Chemistry Escuela de Quimica Southern Illinois University Universidad de Costa Rica Box 1652 San Pedro, San Jose 2060 Edwardsville, IL 62026-1652 Costa Rica USA Tel: +506-207-5325 Tel: +1-618-650-3562 Fax: +506-253-5020 Fax: +1-618-650-3562 [email protected] [email protected]

Pamidipati, Gayairi Hela Pan, Wan-Chun Department of Chemistry Department of Chemistry National Tsing Hua University National Tsing Hua University Hsinchu, 30013 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5715131-3425 Tel: +886-3-5715131-3427 Fax: +886-3-5721614 Fax: +886-3-5721614 [email protected] [email protected]

Pimentel, Giselle Pimentel, Andre S. NASA Goddard Space Flight Center NASA Goddard Space Flight Center Code 691 Code 691 Laboratory for Extraterrestrial Physics Laboratory for Extraterrestrial Physics Greenbelt, MD 20771 Greenbelt, MD 20771 USA USA Tel: +1-301-286-1427 Tel: +1-301-286-1427 Fax: +1-301-286-1683 Fax: +1-301-286-1683 [email protected] [email protected]

49 Pollack, Ilana B. Pradhan, Manik Department of Chemistry Institute of Atomic and Molecular Sciences University of Pennsylvania Academia Sinica Philadelphia, PA 19104-6323 P. O. Box 23-166 USA Taipei, 106 Tel: +1-215-898-5765 Taiwan Fax: +1-215-573-2112 Tel: +886-2-2366-8222 [email protected] Fax: +886-2-2362-0200 [email protected]

Radi, Peter P. Ramsay, Donald A. Paul Scherrer Institut Steacie Institute of Molecular Sciences Department General Energy National Research Council Villigen, CH-5232 Ottawa, K1A 0R6 Switzerland Canada Tel: +41-56-310-4127 Tel: +1-613-237-6667 Fax: +41-56-310-2199 Fax: + [email protected] [email protected]

Reid, Scott A. Rouillé, Gaël Marquette University Joint Laboratory Astrophysics Group Department of Chemistry Institut für Festkörperphysik P. O. Box 1881 Helmholtzweg 3 Milwaukee, WI 53201-1881 Jena, 07743 USA Germany Tel: +1-414-288-7565 Tel: +49-3641-9-47306 Fax: +1-414-288-7066 Fax: +49-3641-9-47308 [email protected] [email protected]

Rowland, F. Sherwood Schatz, George C. Dept. Chemistry and Earth System Sci. Department of Chemistry University of California, Irvine Northwestern University 516 Rowland Hall 2145 Sheridan Rd. Irvine, CA 92697-2025 Evanston, IL 60208-3113 USA USA Tel: +1-949-824-6016 Tel: +1-847-491-5657 Fax: +1-949-824-2905 Fax: +1-847-491-7713 [email protected] [email protected]

Serrano, Adela Seymour, Stephanie G. Departamento de Quimica Fisica I Dipartimento di Chimica Universidad Complutense de Madrid Universita di Perugia Madrid, 28040 Perugia, 06123 Spain Italy Tel: +34-913-944-126 Tel: +39-0755855514 Fax: +34-913-944-135 Fax: +39-0755855606 [email protected] [email protected]

50 Shida, Tadamasa Shiu, Vincent Weicheng Kanagawa Institute of Technology Institute of Atomic and Molecular Sciences 517-95 Iwakura Nagatanicho, Sakyo-ku Academia Sinica Kyoto, 606-0026 P. O. Box 23-166 Japan Taipei, 106 Tel: +81-75-722-7841 Taiwan Fax: +81-75-722-7841 Tel: +886-2-2366-8257 [email protected] Fax: +886-2-2362-0200 [email protected]

Simard, Benoit Skodje, Rex T. Steacie Institute for Molecular Sciences, Department of Chemistry NRC University of Colorado Room 1047-100 Sussex Drive Boulder, Colorado 80309 Ottawa, K1A 0R6 USA Canada Tel: +1-303-492-8194 Tel: +1-613-990-0977 Fax: +1-303-492-5894 Fax: +1-613-991-2648 [email protected] [email protected]

Slenczka, Alkwin Steimle, Timothy C. Department of Physical Chemistry Department of Chemistry and Biochemistry University of Regensburg Arizona State University Universitatsstrasse 31 Tempe, AZ 85287-1604 Regensburg, 92053 USA Germany Tel: +1-480-965-3265 Tel: +49-941-943-4487 Fax: +1-480-965-2747 Fax: +49-941-943-4488 [email protected] [email protected]

Sun, Ying-Chieh Suzuki, Toshinori Department of Chemistry Chemical Dynamics Laboratory National Taiwan Normal University Discovery Research Institute 88, Sec. 4, Ting Chou Rd. RIKEN (Institute of Physical and Chemical Taipei, 116 Research) Taiwan Wako, Saitama, 351-0198 Tel: +886-2-2935-0749x122 Japan Fax: +886-2-2932-4249 Tel: +81-48-467-1433 [email protected] Fax: +81-48-467-1403 [email protected]

Tang, Zichao ter Meulen, E. (Liesbeth) M. J. State Key Laboratory of Molecular Reaction University of Nijmegen Dynamics Toernooiveld 1 Center for Molecular Science Nijmegen, 6525 ED Institute of Chemistry The Netherlands The Chinese Academy of Sci. Tel: +31-243653022 Beijing, 100080 Fax: +31-243653311 China [email protected] Tel: +86-10-6255-8906 [email protected]

51 ter Meulen, J. (Hans) J. Thomas, Richard University of Nijmegen, Toernooiveld 1 Department of Physics Nijmegen, 6525 ED Stockholm University The Netherlands Alba Nova University Center Tel: +31-243653022 Stockholm, SE-106 91 Fax: +31-243653311 Sweden [email protected] Tel: +46-8-55378784 Fax: +46-8-55378601 [email protected]

Timonen, Raimo S. Tsai, Ming-Chang Laboratory of Physical Chemistry Institute of Atomic and Molecular Science University of Helsinki Academia Sinica P. O. Box 55 (A.I. Virtasen aukio 1) P. O. Box 23-166 Helsinki, FIN-00014 Taipei, 106 Finland Taiwan Tel: +358-9-1915-0302 Tel: +886-2-2366-8289 Fax: +358-9-1915-0279 Fax: +886-2-2362-0200 [email protected] [email protected]

Tseng, Shiang Y. Tseng, Chien-Ming Department of Applied Chemistry Institute of Atomic and Molecular Sciences National Chiao Tung University Academia Sinica Hsinchu, 30010 P. O. Box 23-166 Taiwan Taipei, 106 Tel: +886-3-5712121-56551 Taiwan Fax: +886-3-5723764 Tel: +886-2-2366-8268 [email protected] Fax: +886-2-2362-0200 [email protected]

Tsung, Jieh-Wen Tzeng, Wen Bih Department of Physics Institute of Atomic and Molecular Science National Tsing Hua University Academia Sinica 101, Sec. 2, Kuang Fu Road P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-2-2794-4108 Tel: +886-2-2366-8222 Fax: +886-2-2362-0200 Fax: +886-2-2362-0200 [email protected] [email protected]

Varberg, Thomas D. Vázquez, Saulo A. Department of Chemistry Departamento de Química Física Macalester College Facultad de Química 1600 Grand Ave. Avda das Ciencias s/n St. Paul, MN 55105-1899 Santiago de Compostela, 15782 USA Spain Tel: +1-651-696-6468 Tel: +34-981-563100-14228 Fax: +1-651-696-6432 Fax: +34-981-595012 [email protected] [email protected]

52 Vilesov, Alexander A. Vilesov, Andrey F. Department of Chemistry Department of Chemistry University of Southern California University of Southern California 920 West 37th Street 920 West 37th Street Los Angeles, CA 90089 Los Angeles, CA 90089 USA USA Tel: +1-213-821-2936 Tel: +1-213-821-2936 Fax: +1-213-740-3972 Fax: +1-213-740-3972 [email protected] [email protected]

Vilesov, Alla V. Wang, Chia C. Department of Chemistry University of California, Berkeley and University of Southern California Lawrence Berkeley National Laboratory 920 West 37th Street 2308 Warring St Apt 101 Los Angeles, CA 90089 Berkeley, CA 94704 USA USA Tel: +1-213-821-2936 Tel: +1-510-495-2412 Fax: +1-213-740-3972 Fax: +1-510-486-5311 [email protected] [email protected]

Wang, Chia Y. Wang, Li Department of Applied Chemistry Dalian Institute of Chemical Physics National Chiao Tung University 457 Zhongshan Road Hsinchu, 30010 Dalian, 116023 Taiwan China Tel: +886-3-5131516 Tel: +86-411-843-79243 Fax: +886-3-5723764 Fax: +86-411-846-75584 [email protected] [email protected]

Wei, Fang Western, Colin M. Department of Chemistry School of Chemistry Peking University University of Bristol Beijing, 100871 Cantock's Close China Bristol, BS8 1TS Tel: +86-10-627-53786 UK Fax: +86-10-627-51780 Tel: +44-117-928-8653 [email protected] Fax: +44-117-952-0612

Willitsch, Stefan Wong, Yung-Hao Physical Chemistry Lab. Institute of Atomic and Molecular Sciences ETH Honggerberg, HCI E209 Academia Sinica Zurich, CH-8093 P. O. Box 23-166 Switzerland Taipei, 106 Tel: +41-1633-4391 Taiwan Fax: +41-1632-1021 Tel: +886-2-2366-8257 [email protected] Fax: +886-3-2362-0200 [email protected]

53 Wu, Hsing-Chen Wu, Chia Yan Institute of Atomic and Molecular Science Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-5407 Tel: +886-2-2366-8250 Fax: +886-3-5722892 Fax: +886-2362-0200 [email protected] [email protected]

Wu, Di Wu, Yu Jong Institute of Theoretical Chemistry Department of Chemistry Jilin University National Tsing Hua University Changchun, 130023 Hsinchu, 30013 China Taiwan Tel: +86-431-8498964 Tel: +886-3-5715131-3346 Fax: +86-431-8945942 Fax: +886-3-5722892 [email protected] [email protected]

Wu, Hao-Wei Yang, Sheng-Kai Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica National Tsing Hua University P. O. Box 23-166 Hsinchu, 30013 Taipei, 106 Taiwan Taiwan Tel: +886-3-5715131-5407 Tel: +886-2-2366-8217 Fax: +886-3-5722892 Fax: +886-2-2362-0200 [email protected] [email protected]

Yang, Tzung R. Yang, Chia-Ming Department of Applied Chemistry Department of Chemistry National Chiao Tung University National Tsing Hua University Hsinchu, 30010 Hsinchu, 30013 Taiwan Taiwan Tel: +886-3-5712121-56551 Tel: +886-3-5715131-3423 Fax: +886-3-5723764 Fax: + [email protected] [email protected]

Yu, Chin-Hui Yu, Jen-Shiang K. Department of Chemistry Dept. Biological Sci. Technol. National Tsing Hua University National Chiao Tung University 101, Sec. 2, Kuang Fu Road 75, Po-Ai Street Hsinchu, 30013 Hsinchu, 300 Taiwan Taiwan Tel: +886-3-5715131-3411 Tel: +886-3-5726111x56943 Fax: +886-3-5721534 Fax: +886-3-5729288 [email protected] [email protected]

54 Zhang, Alan Zhang, Guiqiu Department of Chemistry Institute of Atomic and Molecular Sciences University of California, Riverside Academia Sinica Riverside, CA 92521-0403 P. O. Box 23-166 USA Taipei, 106 Tel: +1-909-787-4197 Taiwan Fax: +1-909-787-4713 Tel: +886-2-2366-8217 [email protected] Fax: +886-2-2362-0200 [email protected]

Zhang, Bailin Zhang, Kevin Institute of Atomic and Molecular Sciences Department of Chemistry Academia Sinica University of California, Riverside P. O. Box 23-166 Riverside, CA 92521-0403 Taipei, 106 USA Taiwan Tel: +1-909-787-4197 Tel: +886-2-2366-8257 Fax: +1-909-787-4713 Fax: +886-2-2362-0200 [email protected] [email protected]

Zhang, Xu Zhang, Jingsong Department of Chemistry and Biochemistry Department of Chemistry University of Colorado University of California, Riverside Campus Box 215 Riverside, CA 92521-0403 Boulder, CO 80309 USA USA Tel: +1-909-787-4197 Tel: +303-492-5406 Fax: +1-909-787-4713 Fax: +303-492-5894 [email protected] [email protected]

Zhao, Qiuxia Department of Chemistry University of California, Riverside Riverside, CA 92521-0403 USA Tel: +1-909-787-4197 Fax: +1-909-787-4713 [email protected]

55 56 Index of Presenters

Abrash, Samuel A. A2-19 Dagdigian, Paul J. B2-06 Akimoto, Hajime T2 Dyakov, Yuri A. A1-07 Alam, M. S. C1-13 Ehlerding, A. C2-18 Althorpe, Stuart C. C2-02 Endo, Yasuki B2-01 Aoiz, F. J. R4 Fujii, Asuka C2-08 Bahou, Mohammed C1-09 Fujimura, Yo C1-08 Balfour, Walter J. A2-10 Geppert, W. D. B2-20 Balfour, Walter J. B2-11 Graham, W. R. M. A2-18 Bernath, P. A2-09 Guss, Joseph C1-15 Bernath, P. B2-09 Halberstadt, Nadine W4 Bondybey, Vladimir E. W1 Han, Huei-Lin B2-02 Brouard, Mark R3 Han, Ke-Li B1-17 Brown, John M. A2-11 Heaven, Michael C. F1 Butler, L. J. C1-05 Hela, P. G. A1-15 Casavecchia, P. B1-01 Ho, Jr-Wei C1-11 Casavecchia, P. B1-02 Honma, Kenji C1-04 Casavecchia, P. C1-01 Hsu, Yen-Chu F4 Casavecchia, P. C1-02 Hu, Shui-Ming A2-21 Castillo, J. F. A1-11 Huang, Cheng-Liang C2-14 Castillo, J. F. B1-11 Hutson, Jeremy M. F2 Chang, Chih-Wei A1-16 Ishikawa, Haruki B2-08 Chang, Chushuan C1-06 Jacox, Marilyn E. A2-16 Chang, Wei-Zhong A2-03 Jensen, Per A2-07 Chen, Hui-Fen B2-16 Kanamori, H. A2-14 Chen, I-Chia M5 Kato, Hajime C2-13 Chen, Kuo-mei A2-08 Katoh, Kaoru A2-01 Chen, Wei-Kan A1-10 Katoh, Kaoru C2-01 Chen, Yit-Tsong C2-21 Kobayashi, Kaori A2-02 Cheng, Mu-Jeng C1-14 Kumae, Takashi C1-16 Choi, Jong-Ho M7 Larsson, M. B2-18 Chou, Chun-Pang C2-17 Lee, Sheng-Jui C1-10 Chou, Sheng-Lung B1-13 Lee, Shih-Huang A1-05 Chou, Yung-Ching A2-13 Lee, Yin-Yu A1-08 Chou, Yung-Ching B2-13 Leone, Stephen R. M3 Continetti, Robert E. A1-01 Lester, Marsha I. C2-07 Curl, Robert F. T3 Lester, Marsha I. T5

57 Li, Zhi-Ru B1-14 Reid, Scott A. B2-03 Lin, I-Feng A2-15 Reid, Scott A. C2-03 Lin, Jim J. A1-02 Rowland, F. Sherwood T1 Lin, M. C. T4 Schatz, George, C. M8 Lin, Ming-Fu B1-03 Shiu, Vincent W. C. B1-06 Lineberger, W. Carl M2 Simard, Benoit C2-11 Liu, Chen-Lin C1-03 Skodje, Rex T. R2 Liu, Ching-Ping B2-04 Slenczka, Alkwin B1-08 Liu, Ching-Ping C2-04 Steimle, Timothy C. F3 Liu, Kopin R1 Suzuki, Toshinori M1 Liu, Kuan Lin B1-15 ter Meulen, J. J. A2-06 Luh, Wei-Tzou C2-09 ter Meulen, J. J. B1-10 Luo, Liyang B1-16 Thomas, R. D. C2-19 Luther, Klaus C1-12 Timonen, Raimo A1-12 Maier, John P. F5 Tseng, Chien-Ming A1-03 Martínez-Núnez, Emilio B1-07 Tseng, S. Y. A1-13 Matsui, H. B2-19 van de Meerakker, S. Y. T. A2-20 McCunn, L. R. B1-05 Varberg, Thomas D. C2-12 Meijer, Gerard M4 Vázquez, Saulo A. C1-07 Merer, A. J. A2-12 Vilesov, Andrey F. W3 Merkt, Frédéric W2 Wang, Chia C. B2-21 Miller, Terry A. B2-12 Western, C. M. B2-05 Momose, Takamasa W5 Western, C. M. C2-05 Morrison, M. A1-17 Willitsch, Stefan B2-15 Murty, D. V. C2-20 Willitsch, Stefan C2-15 Nee, J. B. B2-14 Wu, Chia-Yan A1-09 Nesbitt, David J. C1-17 Wu, Di A1-14 Neusser, H. J. M6 Wu, Yu-Jong C2-16 Ni, Chi-Kung R5 Yang, Sheng-Kai B1-09 O'Brien, James J. C2-10 Zhang, Bailin A1-06 O'Brien, Leah C. B2-10 Zhang, Guiqiu C2-06 Pimentel, Andre S. B1-12 Zhang, Jingsong A1-04 Pollack, Ilana B. B2-07 Zhang, Jingsong B1-04 Radi, Peter P. A2-04 Zhang, Xu A2-17 Ramsay, D. A. A2-05 Zhang, Xu B2-17

58 Tentative Menu during the Symposium 1. Monday lunch — Braised Seafood Soup with Crab Meat — Cantonese Dim Sum — Fish — Mixed Garden Vegetables — Fried Rice in Cantonese Style — Sweet Dessert

2. Monday dinner — Stewed Chicken Soup — Turnip Cakes and Spring Rolls — Steamed Pork Dumplings — Fried Rice Cakes with Pork and Vegetables — Sautéed Vegetable — Fried Crispy Date Puree Pancake

3. Tuesday lunch — Roast Duck and Honey-glazed Pork — Chicken a la Viceroy (General Tsuo's Chicken) — Steamed Beef on Chinese Cabbage with Gravy — Steamed Fish Fillet — Sautéed Vegetables — Sweet Corn Soup

59 4. Tuesday dinner — Clam Chowder — Bread — Surf and Turf with Vegetable and French Fries — Dessert

5. Wednesday lunch — Clear Tri-shred Soup — Stewed Beef and Bean Curd Roll — Sautéed Chicken with Peanuts in Chili Sauce (Kong Bao Chicken) — Double Stewed Spare Ribs — Steamed Fish with Salty Cucumber — Sautéed Vegetables

6. Friday lunch — Steamed Shrimp Shao Mai and Vegetarian Dumplings — Fried Pork — Braised Noodles — Sautéed Vegetables — Sweet Taro Dessert

60 61 Map of the Taipei MRT

62

Programme of the 27th International Symposium on Free Radicals July 25 July 26 July 27 July 28 July 29 July 30 Sunday Monday Tuesday Wednesday Thursday Friday Chair: YP Lee Chair: SH Lin Chair: Miller Chair: Hepburn Chair: Nesbitt 08:30−09:10 Opening: YT Lee T1 Rowland W1 Bondybey R1 Liu F1 Heaven 09:10−09:50 M1 Suzuki T2 Akimoto W2 Merkt R2 Skodje F2 Hutson 09:50−10:20 Coffee Break Coffee Break Coffee Break Coffee Break Coffee Break Chair: Larsson Chair: ter Meulen Chair: Jacox Chair: Butler Chair: Merer 10:20−11:00 M2 Lineberger T3 Curl W3 Vilesov R3 Brouard F3 Steimle 11:00−11:40 M3 Leone T4 MC Lin W4 Halberstadt R4 Aoiz F4 Hsu 11:40−12:20 M4 Meijer T5 Lester W5 Momose R5 Ni F5 Maier 12:30−14:00 Lunch (B1F, Fu-Chuan Room) Box Lunch Lunch (B1F) Chair: Colin 1-min Oral: C1 & C2 14:00−14:40 M5 Chen IAMS Chair: Zhang 14:40−15:20 M6 Neusser Lab Tour Poster Presentations Conference Tour Tour to 15:20−15:50 Registration Coffee Break (depart at 14:00 W1~W5, R1~R5 (depart at 13:10 Hsinchu (15:00~21:00) Chair: Continetti from the front F1~F5 from the front (depart at 14:00 15:50−16:30 (10F) M7 Choi entrance) C1-01~C1-17 entrance) from the front 16:30−17:10 M8 Schatz or C2-01~C2-21 entrance) 17:10−17:50 Symposium Photo Free Dinner at 17:30 18:00−19:30 Dinner (B1F) Dinner (B1F) (BBQ at Y-S Club) Banquet at 18:30 Reception 1-min Oral: A1 & A2 1-min Oral: B1& B2 Cultural Evening (12F) 19:30−20:30 (1F) Chair: Dagdigian Chair: Shida (at Taipei EYE) (Skylounge) 20:30−22:30 (Grand Garden) Poster Presentations Poster Presentations (buses depart at M1~M8 T1~T5 19:45 from A1-01~A1-17 B1-01~B1-17 Yuan-Shan Club) A2-01~A2-21 B2-01~B2-21