DOCSLIB.ORG

UV-Spectrum of Thioformaldehyde-S-Oxide

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
UV-Spectrum of Thioformaldehyde-S-Oxide Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 Matrix Isolation and Spectroscopic Properties • of the Methylsulfinyl Radical CH3(O)S [a] [b] [b] Hans Peter Reisenauer,* Jaroslaw Romanski, Grzegorz Mloston,* Peter R. Schreiner[a] [a] Justus-Liebig University, Institute of Organic Chemistry, Heinrich-Buff-Ring 58, D-35392 Giessen, Fax: (+49) 641-99-34209; E-mail: [email protected] [b] University of Lodz, Section of Heteroorganic Compounds, Tamka 12, PL-91-403 Lodz, Fax: (+48) (42) 665 51 62; E-mail: [email protected] Supplementary Information Table S1. Experimental (Ar, 10 K) and computed (AE-CCSD(T)/cc-pVTZ, harmonic approximation, no scaling) the IR spectra of 3. 13 3 C-3 D3-3 a b a b a b Sym. Approx. Band Position (Intensity) Band Position (Intensity) Band Position (Intensity) Mode Computation Experiment Computation Experiment Computation Experiment a’’ CH str. 3151.3 (2.1) 2995.4 3139.3 (2.1) n.o. 2336.4 (1.2) 2247.2 a’ CH str. 3149.3 (4.1) (vw) 3137.5 (4.0) n.o. 2334.5 (2.2) (vw) 2919.4 2095.5 a’ CH str. 3065.6 (4.3) 3062.7 (4.5) n.o. 2194.2 (1.4) (vw) (vw) CH 1062.8 a’ 3 1477.4 (6.5) 1417.1 (w) 1474.8 (6.6) 1414.6 (w) 1028.7 (s) def. (17.3) CH a’’ 3 1464.4 (7.8) 1405.2 (w) 1461.7 (7.8) 1401.4 (w) 1058.5 (3.7) 1025.6 (w) def. CH a’ 3 1324.7 (1.0) 1288.7 (w) 1316.2 (0.8) 1283.8 (w) 1024.8 (2.3) 1000.7 (w) def. 1077.8 1077.8 1082.5 a’ SO str. 1068.2 (vs) 1067.9 (vs) 1069.5 (vs) (33.7) (33.8) (20.4) CH a’ 3 944.7 (9.3) 926.6 (m) 936.5 (9.0) 918.9 (m) 765.5 (12.6) 751.6 (w) rock. CH a’’ 3 888.8 (1.1) 868.2 (vw) 883.7 (1.2) 863.5 (vw) 671.8 (0.3) 659.2 (vw) rock. 614.2, a’ CS str. 690.9 (11.9) 669.9 (w) 676.8 (11.9) 656.0 (m) 630.7 (5.9) 618.8 (w) CSO a’ 328.5 (7.1) 340.8 (w) 326.3 (7.) n.o. 298.8 (6.6) n.o. def. CH a’’ 3 134.0 (0.8) n. o. 134.0 (0.8) n.o. 103.1 (1.3) n.o. twist. S1 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 a in cm–1; b in km mol–1 (computation), vw: very weak, w: weak, m: middle, s: strong, vs: very strong, n.o.: not observed (experiment) Experimental Preparation of allylmethyl sulfoxide (4a) and its labelled derivatives 4b and 4c was based on the known protocols.1 A solution of ally1 bromide (1.94 g, 0.016 mol) and thiourea (1.0 g, 0.016 mol) in methanol (20 mL) was heated under reflux for 1 h and then after addition of a methanolic NaOH (1.28 g in 15 mL) solution heating was continued for additional 1 h. Next, the solution was cooled to –10 °C and MeI (2.28 g, 0.016 mol) was added in small portions. The solution obtained thereby was refluxed for 0.5 h. After this time the mixture was distilled and the product 9 was collected as an azeotrope with methanol (bp 62–64 °C). To this solution 30% H2O2 (1.27 g, 0.012 mol) was added dropwise and the reaction mixture was stirred for 6 h at rt. The solvents were evaporated and the liquid residue was distilled to yield allylmethyl sulfoxide (4a), bp 48–50 °C/0.25 Torr. The crude distillate contained traces of allylmethyl sulfone and was directly used for the matrix experiments.used. Note: The same procedure was applied for the synthesis of 4b 13 and 4c using CD3I and CH3I, respectively. Matrix isolation experiments: The cryostat used for the matrix isolation studies was an APD Cryogenics HC-2 closed-cycle refrigerator system fitted with CsI windows for IR and BaF2 windows for UV/Vis measurements. The IR spectra were recorded with a Bruker IFS 55 FTIR spectrometer (4500–300 cm–1, resolution 0.7 cm–1), the UV/Vis spectra with a JASCO V-670 spectrophotometer (spectral range: 190–2500 nm, resolution: >= 0.1 nm). For the combination of high-vacuum flash pyrolysis (HVFP) with matrix isolation a small home built water-cooled oven directly connected to the vacuum shroud of the cryostat was used. The pyrolysis zone consisted of a completely empty quartz tube (inner diameter 8 mm, length of heating zone 50 mm) resistively heated by a coax heating wire. The temperature was controlled by a Ni/CrNi thermocouple. The precursors were evaporated from a cooled storage bulb allylmethyl sulfoxide (4a) at –30 °C (dimethyl sulfoxide (8) at –23 °C) into the quartz pyrolysis tube. Immediately after leaving the tube, at a distance of ca. 50 mm, the pyrolysis products were co-condensed with a large excess of argon on the surface of the 10 K cold matrix window during a time of 2–4 hours. Pyrolysis temperatures were varied between 500 and 900 °C, the optima with respect to the yields of methylsulfinyl radical (3) was found at 600 °C for precursor 4a and 800 °C for 8. For irradiations a mercury high-pressure lamp (Osram, HBO 200 in connection with long-pass glass S2 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 filters or a Bausch & Lomb monochromator (slits set to a spectral half-width of ∆λ = 10 nm), a mercury low pressure lamp (Gräntzel, with vycor filter (λ > 210 nm, main line: λ = 254 nm)), or a KrF excimer laser (Lambda Physik LPX 100, (λ = 248 nm) was used. An unspecific photodegradation of 3 to COS, CS, CO, H2S, H2O was observed using λ = 248 and 254 nm (80 min or 16 h irradiation time for complete conversion), but not with visible light (λ > 475 nm). Subtraction of the respective spectra before and after photodegradation were made to discern the 13 IR and UV/Vis spectra of 3 more clearly. The same procedure was applied for the D3- and C- isotopologues 4b and 4c. Computational methods: The electronic structure computations employed the correlation- consistent triple-ξ atomic-orbital basis set cc-pVTZ.2 Geometry optimizations and evaluations of the analytical harmonic vibrational frequencies were performed with single-reference all-electron coupled-cluster theory, incorporating all single and double excitations, and with perturbative inclusion of connected triple excitations AE-CCSD(T).3 For energy evaluation of all other structures Gaussian-4 theory (G4) was employed.4,5 All stationary structures were characterized as minima or transition structures by computing analytical harmonic vibrational frequencies. For computations of electronic excitations within the adiabatic approximation of time dependent density functional theory (TD-DFT)6 with the B3LYP functional and a large basis set including polarization and diffuse functions (6-311+G(3df,3pd) was employed. 5 References: (1) (a) Prabhuswamy, B.; Ambekar, S. Y. Synth. Comm. 1999, 29, 3477. (b) Kline, M. L.; Beutow, N.; Kim, J. K.; Caserio, M. C. J. Org. Chem. 1979, 44, 1904. (c) O'Connor, D. E.; Lyness, W. I. J. Am. Chem. Soc. 1964, 86, 3840. (2) Dunning Jr., T. H. J. Chem. Phys. 1989, 90, 1007. (3) Stanton, J. F.; Gauss, J.; Harding, M. E.; Szalay P. G. with contributions from Auer, A. A.; Bartlett, R. J.; Benedikt, U.; Berger, C.; Bernholdt, D. E.; Bomble, Y. J.; Cheng, L.; Christiansen, O.; Heckert, M.; Heun, O.; Huber, C.; Jagau, T.-C.; Jonsson, D.; Jusélius, J.; Klein, K.; Lauderdale, W. J.; Matthews, D. A.; Metzroth, T.; Mück, L. A.; O'Neill, D. P.; Price, D. R.; Prochnow, E.; Puzzarini, C.; Ruud, K.; Schiffmann, F.; Schwalbach, W.; Stopkowicz, S.; Tajti, Vázquez, A.; Wang, F.; Watts J. D. and the integral packages MOLECULE (Almlöf, J.; Taylor, P. R.), PROPS (Taylor, P. R.), ABACUS (Helgaker, T.; Jensen, H. J. Aa.; Jørgensen, P.; Olsen, J.), and ECP routines by Mitin, A. V.; van Wüllen, C. For the current version, see http://www.cfour.de. (4) Curtiss, L. A.; Redfern, P. C.; Raghavachari, K. J. Chem. Phys., 2007, 126, 084108. S3 Electronic Supplementary Material (ESI) for Chemical Communications This journal is © The Royal Society of Chemistry 2013 (5) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G. B.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, J. A., Jr.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, J. M.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, Ö.; Foresman, J.
Load more

Recommended publications
  • A Comprehensive Investigation on the Formation of Organo-Sulfur Molecules in Dark Clouds Via Neutral-Neutral Reactions
    A&A 395, 1031–1044 (2002) Astronomy DOI: 10.1051/0004-6361:20021328 & c ESO 2002 Astrophysics A comprehensive investigation on the formation of organo-sulfur molecules in dark clouds via neutral-neutral reactions M. Yamada1, Y. Osamura1, and R. I. Kaiser2;? 1 Department of Chemistry, Rikkyo University, 3-34-1 Nishi-ikebukuro, Tokyo 171-8501, Japan 2 Department of Chemistry, University of York, YO10 5DD, UK Received 11 June 2002 / Accepted 9 September 2002 Abstract. Fifteen reactions on the doublet HCnS and singlet/triplet H2CnS(n = 1; 2) potential energy surfaces have been investi- gated theoretically via electronic structure calculations to unravel the formation of hydrogen deficient, sulfur bearing molecules via bimolecular reactions of two neutral species in cold molecular clouds. Various barrierless reaction pathways to synthe- size astronomically observed CnS and hitherto undetected HCnS(n = 1; 2) isomers are offered. These data present important 2 2 guidance to search for rotational transitions of the elusive thioformyl HCS(X A0) and thioketenyl HCCS(X Π) radicals in the interstellar medium. Key words. astrochemistry – ISM: molecules – molecular processes – methods: miscellaneous 1. Introduction terminated counterparts HCnSandCnSH have not been de- tected in the interstellar medium yet. However, these molecules Untangling the synthetic routes to form sulfur-carrying might represent the missing source of molecular-bound sul- molecules in the interstellar medium is a significant instru- fur in the interstellar medium. Hydrogen deficient organosul- ment to understand the chemical evolution and physical con- 2 2 fur molecules like HCS(X A0) and HCCS(X Π) resemble also ditions in star forming regions and in circumstellar envelopes important reaction intermediates which could lead to sulfur (Minh & van Dishoeck 2000).
    [Show full text]
  • H2CS) and Its Thiohydroxycarbene Isomer (HCSH
    A chemical dynamics study on the gas phase formation of thioformaldehyde (H2CS) and its thiohydroxycarbene isomer (HCSH) Srinivas Doddipatlaa, Chao Hea, Ralf I. Kaisera,1, Yuheng Luoa, Rui Suna,1, Galiya R. Galimovab, Alexander M. Mebelb,1, and Tom J. Millarc,1 aDepartment of Chemistry, University of Hawai’iatManoa, Honolulu, HI 96822; bDepartment of Chemistry and Biochemistry, Florida International University, Miami, FL 33199; and cSchool of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom Edited by Stephen J. Benkovic, The Pennsylvania State University, University Park, PA, and approved August 4, 2020 (received for review March 13, 2020) Complex organosulfur molecules are ubiquitous in interstellar molecular sulfur dioxide (SO2) (21) and sulfur (S8) (22). The second phase clouds, but their fundamental formation mechanisms have remained commences with the formation of the central protostars. Tempera- largely elusive. These processes are of critical importance in initiating a tures increase up to 300 K, and sublimation of the (sulfur-bearing) series of elementary chemical reactions, leading eventually to organo- molecules from the grains takes over (20). The subsequent gas-phase sulfur molecules—among them potential precursors to iron-sulfide chemistry exploits complex reaction networks of ion–molecule and grains and to astrobiologically important molecules, such as the amino neutral–neutral reactions (17) with models postulating that the very acid cysteine. Here, we reveal through laboratory experiments, first sulfur–carbon bonds are formed via reactions involving methyl electronic-structure theory, quasi-classical trajectory studies, and astro- radicals (CH3)andcarbene(CH2) with atomic sulfur (S) leading to chemical modeling that the organosulfur chemistry can be initiated in carbonyl monosulfide and thioformaldehyde, respectively (18).
    [Show full text]
  • Thermal Averaging of the Indirect Nuclear Spin-Spin Coupling Constants of Ammonia: the Importance of the Large Amplitude Inversion Mode Andrey Yachmenev, Sergei N
    Thermal averaging of the indirect nuclear spin-spin coupling constants of ammonia: The importance of the large amplitude inversion mode Andrey Yachmenev, Sergei N. Yurchenko, Ivana Paidarová, Per Jensen, Walter Thiel, and Stephan P. A. Sauer Citation: J. Chem. Phys. 132, 114305 (2010); doi: 10.1063/1.3359850 View online: https://doi.org/10.1063/1.3359850 View Table of Contents: http://aip.scitation.org/toc/jcp/132/11 Published by the American Institute of Physics Articles you may be interested in Accurate ab initio vibrational energies of methyl chloride The Journal of Chemical Physics 142, 244306 (2015); 10.1063/1.4922890 Automatic differentiation method for numerical construction of the rotational-vibrational Hamiltonian as a power series in the curvilinear internal coordinates using the Eckart frame The Journal of Chemical Physics 143, 014105 (2015); 10.1063/1.4923039 Theoretical rotation-vibration spectrum of thioformaldehyde The Journal of Chemical Physics 139, 204308 (2013); 10.1063/1.4832322 High-level ab initio potential energy surfaces and vibrational energies of H2CS The Journal of Chemical Physics 135, 074302 (2011); 10.1063/1.3624570 A highly accurate ab initio potential energy surface for methane The Journal of Chemical Physics 145, 104305 (2016); 10.1063/1.4962261 Ro-vibrational averaging of the isotropic hyperfine coupling constant for the methyl radical The Journal of Chemical Physics 143, 244306 (2015); 10.1063/1.4938253 THE JOURNAL OF CHEMICAL PHYSICS 132, 114305 ͑2010͒ Thermal averaging of the indirect nuclear spin-spin coupling constants of ammonia: The importance of the large amplitude inversion mode Andrey Yachmenev,1 Sergei N.
    [Show full text]
  • Structural Features of the Carbon-Sulfur Chemical Bond: a Semi-Experimental Perspective Supporting Information
    Structural features of the carbon-sulfur chemical bond: a semi-experimental perspective Supporting Information Emanuele Penocchio, Marco Mendolicchio, Nicola Tasinato, and Vincenzo Barone∗ Scuola Normale Superiore, Pisa, Italy E-mail: [email protected] ∗To whom correspondence should be addressed 1 In Table 1 we focus on molecules reported in Table 2 of the main article and compare reference SE equilibrium parameters with ab-initio predictions obtained with B3LYP/SNSD, B2PLYP/VTZ, M06-2X, and BHandH model chemistries. β In Table 2, experimental rotational constants, ∆Bvib calculated at B3LYP/SNSD and B2PLYP/VTZ β levels of theory, and ∆Bel calculated at B3LYP/AVTZ level are reported for all the species discussed in the main text. Table 1: Comparison between reference SE equilibrium parameters and ab-initio ones ob- tained using functionals with a different amount of Hartree-Fock exchange (see main text). Distances in A,˚ angles in degrees. Atom numbering as in Figure 2 of the main work. SEa re re B3LYP/SNSD B2PLYP/VTZ M06-2X/VTZ BHandH/VTZ SE { Sulfur chains { isothiocyanic acid r(S-C) 1:5832 1:5744 1:5713 1:5588 1:5678(7) r(C-N) 1:2091 1:2047 1:1922 1:179 1:2047(9) r(N-H) 1:0102 1:0035 1:0035 0:9974 1:0070(9) a(S-C-N) 173:77 173:95 174:81 175:42 172:23(18) a(H-N-C) 129:67 131:50 134:72 137:28 129:75(5) thioformaldehyde r(S-C) 1:6227 1:6135 1:60089 1:58782 1:6093(1) r(C-H) 1:0918 1:0859 1:08702 1:0849 1:0854(2) a(H-C-S) 121:95 122:01 122:025 121:964 121:73(2) thioketene r(S-C) 1:5724 1:5623 1:5546 1:5426 1:5556(4) r(C-C) 1:3107 1:3082 1:3021 1:2899 1:3107(5) r(C-H) 1:0863 1:0801 1:0811 1:0793 1:0806(1) a(C-C-H) 120:66 120:46 120:31 129:34 120:15(1) propadienethione r(S1-C2) 1:5876 1:5776 1:5673 1:5546 1:5715(15) r(C2-C3) 1:2722 1:2691 1:2679 1:2571 1:2702(18) r(C3-C4) 1:3223 1:3191 1:3119 1:3003 1:3228(9) r(C4-H) 1:0905 1:0848 1:0851 1:0832 1:0842(3) a(H-C4-C3) 121:80 121:68 121:48 121:49 121:20(2) 2 β β Table 2: Experimental rotational constants, ∆Bvib, and ∆Bel are reported for all the species discussed in the main text.
    [Show full text]
  • Version 038 – Exam 2 – Mccord – (53130) 1 This Print-Out Should
    Version038–Exam2–McCord–(53130) 1 This print-out should have 31 questions. 3. sp3 Multiple-choice questions may continue on the next column or page – find all choices 4. Pure pz orbitals are used in bonding. before answering. 5. sp3d McCord CH301tt Explanation: The structure is b b b This exam is only for b O McCord’s Tues/Thur CH301 class. C If Quest works properly, you should be able H3C CH3 to see your score for this exam by 11:30 PM tonight. Do realize however that Quest has 003 10.0 points been taking up to 8 hours to get through the Which of the molecules b b b grading, so your score might appear bit by bit. b O I will post an announcement on our web page I) and/or Quest when I feel like all bubblesheets H H have been graded. b b b b b b Cl PLEASE carefully bubble in your UTEID and Version Number! We av- II) b b B b b b erage about 20-30 students per exam that b b b b Cl Clb b misbubble this information. Get it right! b b b b b b b b III) b Cl Cl b b b b 001 10.0 points contains polar covalent bonds but is NOT Choose the species that is incorrectly matched itself a polar molecule? with electronic geometry about the central atom. 1. III only 1. CF4 : tetrahedral 2. II and III only 2. BeBr2 : linear 3. I and II only 3. H2O : tetrahedral 4.
    [Show full text]
  • Anchoring the Potential Energy Surfaces of Homogenous and Heterogenous Dimers of Formaldehyde and Thiofomaldehyde
    ANCHORING THE POTENTIAL ENERGY SURFACES OF HOMOGENOUS AND HETEROGENOUS DIMERS OF FORMALDEHYDE AND THIOFOMALDEHYDE by Christina Michelle Holy A thesis submitted to the faculty of The University of Mississippi in partial fulfillment of the requirements of the Sally McDonnell Barksdale Honors College Oxford May 2014 Approved by _____________________________________ Advisor: Professor Gregory Tschumper _____________________________________ Reader: Associate Professor Nathan Hammer _____________________________________ Reader: Professor Susan Pedigo © 2014 Christina Michelle Holy ALL RIGHTS RESERVED ii ACKNOWLEDGEMENTS Many people in the Department of Chemistry and Biochemistry here at the University of Mississippi were of great assistance during the work presented in this manuscript. I would like to thank the Mississippi Center for Supercomputing Research for the use of their computational facilities and the research group of Dr. Gregory Tschumper for their guidance and computational assistance. Specifically, I would like to thank Eric Van Dornshuld for his continual support and advisement throughout this research project. Lastly, I would like to thank my advisor, Dr. Gregory Tschumper, for allowing me to work in his laboratory as well as providing me with a worthwhile project to fulfill this thesis requirement. iii ABSTRACT This work characterizes five stationary points of the formaldehyde dimer, (CH2O)2, two of which are minima, seven newly-identified stationary points of the formaldehyde/thioformaldehyde (mixed) dimer, CH2O/CH2S, four of which are minima, and five newly-identified stationary points of the thioformaldehyde dimer, (CH2S)2 , three of which are minima. Full geometry optimizations and corresponding harmonic vibrational frequencies were performed on CH2O and CH2S as well as each of the dimer configurations (Figures 3-5).
    [Show full text]
  • TA-02 Ion Science PID Response Factors USA V1.6.Pdf 1.43 MB
    Technical/Application Article 02 Version 1.6 19 July 2016 WRH/FD Ion Science PID Response Factors PID Response Photoionization Detectors (PIDs) respond to a broad range of organic and a few inorganic gaseous and volatile chemicals (‘volatiles’). In order for PID to respond to a volatile, the photon energy of the lamp must be greater than its ionization energy. Ion Science PIDs are available with 10.0 eV, 10.6 eV, and 11.7 eV lamps. This Technical Article lists the response factors (‘RF’s’) for over 800 volatiles with PID engaging these lamps. The RF relates the sensitivity of PID to a volatile to the sensitivity to the standard calibration gas isobutylene. The higher the RF, the lower the sensitivity. In the table ‘ZR’ means there is no response, NA that the value has not been measured (Not Available), and NV means that the compound is not volatile enough to measure accurately. For chemicals not listed, contact Ion Science for more information. Isobutylene as Reference Gas It is always most accurate to calibrate a PID directly with the compound to be measured. However, standard gas cylinders of many chemicals are not readily available, and in such cases isobutylene is the standard reference gas used to calibrate. The response of these chemicals differs to isobutylene by the factors listed in the table below. This table allows measurement of all the listed volatiles using only isobutylene for calibration. To obtain the true concentration of the target volatile chemical, multiply the apparent reading by the response factor listed in the table: True Concentration = Apparent Response x Response Factor For example, anisole has a response factor (RF) of 0.47 with a 10.6 eV lamp.
    [Show full text]
  • Criegee Intermediate-Hydrogen Sulfide Chemistry at the Air/Water
    Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Criegee intermediate-hydrogen sulfide chemistry at the air/water interface† Cite this: Chem. Sci.,2017,8,5385 Manoj Kumar,‡a Jie Zhong,‡a Joseph S. Francisco*a and Xiao C. Zeng*ab We carry out Born–Oppenheimer molecular dynamic simulations to show that the reaction between the smallest Criegee intermediate, CH2OO, and hydrogen sulfide (H2S) at the air/water interface can be observed within few picoseconds. The reaction follows both concerted and stepwise mechanisms with former being the dominant reaction pathway. The concerted reaction proceeds with or without the Received 22nd April 2017 involvement of one or two nearby water molecules. An important implication of the simulation results is Accepted 9th May 2017 that the Criegee-H2S reaction can provide a novel non-photochemical pathway for the formation of DOI: 10.1039/c7sc01797a aC–S linkage in clouds and could be a new oxidation pathway for H2S in terrestrial, geothermal and rsc.li/chemical-science volcanic regions. Creative Commons Attribution 3.0 Unported Licence. Carbon–sulfur linkages are ubiquitous in atmospheric, combus- hydrogen sulde (H2S) under water or acid catalysis could account tion, and biological chemistries. Thioaldehydes comprise an for the atmospheric formation of thioaldehydes and provide useful important class of carbon–sulfur compounds that has a broad guidelines for efficiently synthesizing thioaldehydes within labo- chemical appeal. For example, thioformaldehyde (HCHS) has been ratory environment.7,9
    [Show full text]
  • Submillimeter-Wave Spectroscopy of and Interstellar Search for Thioacetaldehyde
    Submillimeter-wave spectroscopy of and interstellar search for thioacetaldehyde L. Margul`esa, V. V. Ilyushinb,c,∗, B. A. McGuired, A. Bellochee, R. A. Motiyenkoa, A. Remijand, E. A. Alekseevb,c, O. Dorovskayab, J.-C. Guilleminf aUniv. Lille, CNRS, UMR 8523 - PhLAM - Physique des Lasers Atomes et Mol´ecules,F-59000 Lille, France bInstitute of Radio Astronomy of NASU, 4, Mystetstv St., Kharkiv, 61002, Ukraine cQuantum Radiophysics Department, V.N. Karazin Kharkiv National University, Svobody Square 4, 61022, Kharkiv, Ukraine dNational Radio Astronomy Observatory, Charlottesville, VA 22903, USA eMax-Planck-Institut f¨urRadioastronomie, Auf dem H¨ugel69, 53121 Bonn, Germany fUniv. Rennes, Ecole Nationale Sup´erieure de Chimie de Rennes, CNRS, ISCR { UMR 6226, F-35000 Rennes, France Abstract We present a new study of the millimeter and submillimeter wave spectra of the thioacetaldehyde molecule, CH3CHS, a sulfur-bearing analog of the ubiquitous interstellar molecule acetaldehyde (CH3CHO). Here, we present a laboratory investigation aimed at determining accurate spectroscopic parameters for CH3CHS to enable astronomical searches for this molecule using radio telescope arrays at millimeter and submillimeter wavelengths. New laboratory measurements have been carried out between 150 and 660 GHz using the spectrometer of PhLAM in Lille (France). Rotational transitions up to J = 60 were assigned in the ground, first and second excited torsional states of thioacetaldehyde and fit using the RAM Hamiltonian model. The final fit includes 62 parameters to give an overall weighted root-mean-square deviation of 0.9. On the basis of our spectroscopic results, CH3CHS was searched for, but not detected, in data from the Atacama Large Millimeter/submillimeter Array (ALMA) between 84 GHz and 114 GHz toward the hot molecular core Sgr B2(N2).
    [Show full text]
  • OLCT200 PID Application Note
    OLCT200 PID Application note PID Response Factor PID Response Photoionization Detectors (PIDs) respond to a broad variety of organic gases and vapors, and some inorganic compounds. In order to get a response, the photon energy of the lamp must be greater than the ionization energy of the compound. PIDs are available with 10.6 eV lamps. This Technical Article lists the response factors for over 800 compounds with these lamps. The factors presented are inverse to the response, i.e., the higher the number the lower the response. In the table ‘ZR’ means there is no response, NA that the value has not been measured (Not Available), and NV means that the compound is not volatile enough to measure accurately even if its ionization energy is low enough. Isobutylene as Reference Gas It is always most accurate to calibrate a PID directly with the compound to be measured. However, standard gas cylinders of many chemicals are not readily available, and in such cases isobutylene is the standard reference gas used to calibrate. The response of these chemicals differs to isobutylene by the factors listed in the table below. This table allows measurement of any of the compounds in it using only isobutylene for calibration. To obtain the true concentration of the target chemical, multiply the apparent reading by the response factor listed in the table: True Concentration = Apparent Response x Response Factor For example, anisole has a response factor (RF) of 0.47 with a 10.6 eV lamp. Therefore, a reading of 10 ppm using an isobutylene-calibrated unit would correspond to: True Concentration = 10 ppm x 0.47 = 4.7 ppm Most of the Response Factors are pre-programmed into a compound library and can be called up to make the PID read out in units of the compound of interest.
    [Show full text]
  • Electron Induced Chemistry of Thioformaldehyde
    RSC Advances Electron induced chemistry of Thioformaldehyde Journal: RSC Advances Manuscript ID RA-ART-09-2015-019662.R1 Article Type: Paper Date Submitted by the Author: 11-Nov-2015 Complete List of Authors: Limbachiya, Chetan; The M. S. University Baroda, Vadodara - 390001, Department of applied Physics CHAUDHARI, ASHOK; Government Engineering College Patan,, PHYSICS DESAI, HARDIK; DEPARTMENT OF PHYSICS, SARDAR PATEL UNIVERSITY, VALLABH VIDYANAGAR, PHYSICS VINODKUMAR, MINAXI; V.P & R.P.T.P. SCIENCE COLLEGE, ELECTRONICS; P.G. DEPARTMENT OF PHYSICS, SARDAR PATEL UNIVERSITY, PHYSICS Subject area & keyword: Biophysics - Physical < Physical Page 1 of 15 RSC Advances Electron induced chemistry of Thioformaldehyde Chetan Limbachiyaa,Ashok Chaudharib, Hardik Desaic and Minaxi Vinodkumar∗d Received Xth XXXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX First published on the web Xth XXXXXXXXXX 200X DOI: 10.1039/b000000x A comprehensive theoretical study is carried out for electron interactions with thioformaldehyde (H2CS) over a wide range of impact energies (0.01 eV to 5000 eV). Owing to wide energy range we have been able to compute target properties and investigate variety of processes and report data on resonances, vertical electronic excitation energies, differential cross sections (DCS), momentum transfer cross sections (MTCS), total ionization cross sections (TICS) and total cross sections (TCS) as well as scattering rate coefficients. Due to complexity involved in scattering calculations, two different theoretical formalisms are used. We have employed ab initio R-matrix method (0.01 eV to ∼ 20 eV) and the spherical complex optical potential (SCOP) method (∼20 eV to 5000 eV) to compute the cross sections. The R-matrix calculations are performed using close coupling approximation employing static exchange plus polarization (SEP) model with the aid of basis sets, 6-31G* (14 target states) and cc-pVTZ (16 target states).
    [Show full text]
  • A Study of the Charge Distribution in Unconjugated Thiocarbonyl Compounds: a Comparison with Carbonyl and Imine Chromophores
    South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Electronic Theses and Dissertations 1974 A Study of the Charge Distribution in Unconjugated Thiocarbonyl Compounds: a Comparison with Carbonyl and Imine Chromophores John Yuchu Lee Follow this and additional works at: https://openprairie.sdstate.edu/etd Recommended Citation Lee, John Yuchu, "A Study of the Charge Distribution in Unconjugated Thiocarbonyl Compounds: a Comparison with Carbonyl and Imine Chromophores" (1974). Electronic Theses and Dissertations. 4734. https://openprairie.sdstate.edu/etd/4734 This Thesis - Open Access is brought to you for free and open access by Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact [email protected]. STUDY CB1'RGE DISTRIBUTION UNCONJUGATED A OF THE Id THIOCARI30NYL COMPOUNDS: COMPARISON A WITH THE CARBONYL AND IMINE CHRO!-DPHORES . BY JOHN LEE YUCHU �.UTH _DAKOTA STATE UNIVERSITY LIBRARY thesis A su:C:-:iitted fulfill::1ent of the the in partial requirer,ents for degree in Master of Cheriistry, Science, ��jor South Dakota State Unive1·sity 1974 '1, I A STUDY OF THE CHARGE DISTRIBUTION IN UNCONJUGATED THIOCARBONYL COMPOUNDS: A COMPARISON WITH THE CARBONYL AND IMINE CHROr-OPHORES Abstract JOHN YUCHU LEE Under the supervision of Dr . James Worman Via a literature search it has been shown, by means of the ira spectra of thioamides, the dipole moments of thiocarbonyl compounds , the basicity of thioamides and thioureas, the acidity of carboxylic acids carrying a substituent with the thiocarbonyl function, LCAO-b method, and proton· chemical shifts, that the thiocarbonyl group me has tendency to give a greater mesomeric interaction than the (�) carbonyla group (£) with electron donating heteroatoms.
    [Show full text]