Zinc Sulfide – Zns and Zns-MS

Total Page：16

File Type：pdf, Size：1020Kb

Zinc Sulfide – ZnS and ZnS-MS Product Information Polycrystalline ZnS is produced by a Chemical Vapor Deposition process (CVD). Polycrystalline Zinc Sulfide is for both military and industrial applications. It is available in large sizes and custom shapes and formats. These may include windows, domes, or lens blanks. Two grades of ZnS are available: Regular (FLIR) grade Zinc Sulfide is a polycrystalline optical material with high performance in fracture strength and hardness. ZnS is often used in the 8-12µm region. Its resistance to rain and particle erosion coupled with its lower relative cost provide ZnS with an edge over ZnS-MS and ZnSe in many applications, such as IR windows for military systems. MultiSpectral (Clear) grade Zinc Sulfide is ZnS treated after growth with a hot isostatic process to eliminate microscopic voids and defects which occur in the regular grade material. This processing results in a clear material. ZnS-MS is commonly used in applications across the visible to infrared region from 0.45 - 12µm. Wavelength Index Transmission Material Properties µm FLIR % MultiSp (6mm) 0.46 2.516 0 65 Optical Properties FLIR MultiSp 0.50 2.419 5 67 Bulk Absorption Coefficient (10.6 µm) <0.24 <0.20 0.66 2.342 8 69 Thermal Change dn/dT x 10 -6 .66µm 41 54 0.80 2.313 12 71 Refractive Index Inhomogeneity <100 10.6µm <20 .66µm 1.00 2.292 18 72 Thermal Properties 3.00 2.257 46 72 Thermal Conductivity (20oC) W/mK 16.7 27.2 Specific Heat J/gK 0.469 0.527 4.00 2.252 52 73 5.00 2.246 63 73 Thermal Expansion (20oC) x 10 -6/K 6.8 6.5 6.00 2.239 50 72 Mechanical Properties 7.00 2.232 68 74 Rupture Modulus MPa 103 69 8.00 2.223 73 74 Young’s Modulus GPa 74 88 9.00 2.212 74 75 Hardness (Knoop) Kg/mm2 210-240 150-165 10.00 2.200 74 75 Poisson’s Ratio 0.27 0.27 11.00 2.186 58 58 Density g/cm3 4.08 4.09 12.00 2.700 61 61 Zinc Sulfide – ZnS and ZnS-MS Transmission Curves For more information please contact: Advanced Optics SCHOTT North America, Inc. Phone: +1 (0) 570/457-7485 400 York Avenue Fax: +1 (0) 570/457-7330 Duryea, PA 18642 [email protected] USA www.us.schott.com/advanced_optics Produced for SCHOTT by VITRON Spezialwerkstoffe GmbH.

Copy Link

Recommended publications

Zns(Ag) Zinc Sulfide Scintillation Material
ZnS(Ag) ® Zinc Sulfide Scintillation Material Properties – Density [g/cm3] ............................................... 4.09 Silver activated zinc sulfide has a very high scintillation efficiency Cleavage plane ........................... polycrystalline comparable to that of NaI(Tl). It is only available as a polycrystalline Wavelength of emission max. [nm] ........ 450 powder. Lower wavelength cutoff [nm] ................ 330 Refractive index @ emission max .......... 2.36 Photoelectron yield [% of NaI(Tl)] (for γ-rays) ZnS(Ag) has a maximum in the incident α-particles. The broad peak is ................................................................................ 130 scintillation emission spectrum at clearly above the electronic noise. Decay constant [ns] ....................................... 110 450nm. The light conversion efficiency ZnS(Ag) can be used to detect thermal is relatively poor for fast electrons neutrons if a lithium compound which may be an advantage when enriched in 6Li is incorporated. The detecting heavy ionizing particles in a alpha particle and triton from the 6Li relatively intense γ-ray background. (n, α) 3H reaction produce scintilla- Scintillation decay times between tions upon interacting with the several hundreds of ns and 10µs are ZnS(Ag). The figure also shows a reported and phosphorescence of still thermal neutron spectrum. longer duration has been noted. Another use for ZnS(Ag) is for the Thicknesses greater than about 25 detection of fast neutrons. A fast mg/cm2 become unusable because of neutron detector is made by imbed- the opacity of the multicrystalline ding the ZnS(Ag) in a clear hydrog- layer to its own luminescence. enous compound. The neutrons are Its use is limited to thin screens used detected by measuring the recoiling primarily for α-particles or other proton from a neutron proton heavy ion detection.
[Show full text]
Determination of Zinc Sulfide Solubility to High Temperatures
Downloaded from orbit.dtu.dk on: Sep 25, 2021 Determination of Zinc Sulfide Solubility to High Temperatures Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan Published in: Journal of Solution Chemistry Link to article, DOI: 10.1007/s10953-017-0648-1 Publication date: 2017 Document Version Peer reviewed version Link back to DTU Orbit Citation (APA): Carolina Figueroa Murcia, D., Fosbøl, P. L., Thomsen, K., & Stenby, E. H. (2017). Determination of Zinc Sulfide Solubility to High Temperatures. Journal of Solution Chemistry, 46(9-10), 1805-1817. https://doi.org/10.1007/s10953-017-0648-1 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Determination of Zinc Sulfide Solubility to High Temperatures Diana Carolina Figueroa Murcia1, Philip L. Fosbøl1, Kaj Thomsen1*, Erling H. Stenby2 1Center for Energy Resources Engineering, CERE, Department of Chemical and Biochemical Engineering, Technical University of Denmark, DTU 2Department of Chemistry, Technical University of Denmark, DTU * Corresponding author: Kaj Thomsen [email protected] Abstract A new experimental set-up and methodology for the measurement of ZnS solubility in aqueous solutions at 40, 60 and 80 ˚C (atmospheric pressure) is presented.
[Show full text]
Chemical Deposition of Zinc Hydroxosulfide Thin Films from Zinc (II) - Ammonia-Thiourea Solutions B
Chemical Deposition of Zinc Hydroxosulfide thin Films from Zinc (II) - Ammonia-Thiourea Solutions B. Mokili, M. Froment, D. Lincot To cite this version: B. Mokili, M. Froment, D. Lincot. Chemical Deposition of Zinc Hydroxosulfide thin Films from Zinc (II) - Ammonia-Thiourea Solutions. J. Phys. IV, 1995, 05 (C3), pp.C3-261-C3-266. 10.1051/jp4:1995324. jpa-00253690 HAL Id: jpa-00253690 https://hal.archives-ouvertes.fr/jpa-00253690 Submitted on 1 Jan 1995 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE lV Colloque C3, supplCment au Journal de Physique 111, Volume 5, avril 1995 Chemical Deposition of Zinc Hydroxosulfide thin Films from Zinc (11) - Ammonia-Thiourea Solutions B. Mokili, M. Froment* and D. ~incot(1) Laboratoire d'Electrochimie et de Chimie Analytique, Unite' Associke au CNRS, Ecole Nationale Supe'rieure de Chimie de Paris, I I rue Pierre et Marie Curie, 75231 Paris cedex 05, France * UPR 15 du CNRS "Physiquedes Liquides et Electrochimie", Universite' Pierre et Marie Curie, 75252 Paris cedex 05, France Abstract The growth of ZnS films from ammonia solutions using thiourea as a sulfur precursor has been investigated.
[Show full text]
SPI Supplies Division Safety Data Sheet Section
SPI Supplies Division Safety Data Sheet Structure Probe, Inc. 206 Garfield Ave., West Chester, PA 19381-0656 USA Date Effective: March 8, 2017 Phone: 1-(610)-436-5400 Fax: 1-(610)-436-5755 [email protected] SPI Catalog # 04129-AB SPI-Chem™ TEM Screen http://www.2spi.com Recoating Phosphor Powder Manufacturer's CAGE: 1P573 Section 1.1: Identification Chemical Name/Synonyms ....... Phosphor powder; Zinc Sulfide: Copper Aluminum Activated Product or Trade Name ............. SPI-Chem™ TEM Screen Recoating Phosphor Powder CAS #'s ...................................... 68611-68-7 Chemical Formula ...................... ZnS:Cu,Al Section 1.2: Relevant Uses/Restrictions TEM Screen recoating powder Section 1.3: Supplier of the Safety Data Sheet SPI Supplies Division Structure Probe, Inc. 206 Garfield Ave., West Chester, PA 19381-0656 USA Phone: 1-(610)-436-5400 Fax: 1-(610)-436-5755 [email protected] http://www.2spi.com Manufacturer's CAGE: 1P573 Section 1.4: Emergency telephone number Emergencies Contacting CHEMTREC: 24 Hour Emergency Use Only #'s... Worldwide phone: 1-(703)-741-5970 Toll-free phone: 1-(800)-424-9300 USA + Canada only Section 2: Hazard Identification 2.1 Classification of the substance Not a hazardous substance or mixture. 2.2 Label elements, including precautionary statements Not a hazardous substance or mixture 1 2.3 Other Hazards: None known. Hazardous Material Information System USA Health ........................... 1 Fire Hazard ................... 0 Reactivity ...................... 0 Personal Protection ...... NFPA Rating (estimated) Health ........................... 0 Flammability .................. 0 Reactivity ...................... 0 Section 3: Composition 3.1 Substances: This material contains greater than 99% Zinc Sulfide. No TLV or PEL has been established for Zinc Sulfide. The TLV for particulates not otherwise classified is 10 mg/m3.
[Show full text]
Inorganic Chemistry Test for Zinc Radical
Chemistry Inorganic Chemistry Test for Zinc Radical General Aim Method Detection of the presence of zinc ion as a base radical in Detection of the presence of zinc as a base radical inorganic salts such as zinc sulfate. using specic chemical reagents. Learning Objectives (ILOs) Dene and dierentiate between members of the third group cations and those of other cation groups. Classify inorganic salts according to their base radicals. Compare between zinc containing salts and other members of the same group in terms of chemical structures, properties and reactions. Identify zinc radicals containing salts experimentally. Select the appropriate reagents to detect the presence of zinc radical. Balance the chemical equations of chemical reactions. Theoretical Background/Context - Zinc (Zn), is a metal whose atomic number is 30 and it is the rst element located in group 12 in the periodic table. Its name is derived from the German word zink. Zinc is similar to magnesium in size and both of them possess only one oxidation state which is +2. Abundance of Zinc in Nature In the Earth’s crust, zinc is the 24th most abundant element in the earth crust and possesses ve isotopes. The most widely abundant zinc ore is sphalerite which is a zinc sulde based ore. It is also commonly known as zinc blende. The largest workable zinc ores lodes are located in the United States of America, Australia and Asia. Zinc metal is obtained through the renement of its ores through their froth otation, roasting, then nal extraction using electricity (electrowinning). Properties and Uses of Zinc - Zinc is a slightly brittle and ductile metal at room temperature possessing a blue silvery appearance.
[Show full text]
Zinc Sulfide-Sulfate Reaction Pressures" (1963)
Scholars' Mine Masters Theses Student Theses and Dissertations 1963 Zinc sulfide-sulfate eactionr pressures William L. Hallerberg Follow this and additional works at: https://scholarsmine.mst.edu/masters_theses Part of the Metallurgy Commons Department: Recommended Citation Hallerberg, William L., "Zinc sulfide-sulfate reaction pressures" (1963). Masters Theses. 2810. https://scholarsmine.mst.edu/masters_theses/2810 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. ZINC SULFIDE - SULFATE REACTION PRESSURES by William L. Hallerberg A Thesis Submitted to the Faculty of the University of Missouri School of Mines and Metallurgy in partial fulfillment of the requirements for the Degree of Master of Science in Metallurgical Engineering Rolla, Missouri 1963 Approved by: Advisor ABSTRACT A static manometric method was used to find the equilibrium reaction pressure as a function of temperature for the reaction: 11 ZnS04 + ZnS --> 4 (Zn0*2ZnS04 ) + 4 S02 From the reaction pressures, the standard free energy of the reaction was found to be: AF° = + 51,320 - 36.68 T Using thermodynamic data for ZnS04, ZnS and S02 the standard free energy of formation of the basic salt Zn0*2ZnS04 was found to be: AF° = - 377,000 - 6 5 . 9 T cal/mole in the temperature range 350 to 420° C. Above 420° C. the reaction, 2 ZnS + 3 (ZnO.2ZnSO4 ) --> 11 ZnO + 8 S02 proceeds. ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Dr.
[Show full text]
Functionalisation of Colloidal Transition Metal Sulphides Nanocrystals: a Fascinating and Challenging Playground for the Chemist
crystals Review Functionalisation of Colloidal Transition Metal Sulphides Nanocrystals: A Fascinating and Challenging Playground for the Chemist Silvia Gross 1,2,*, Andrea Vittadini 1,2 and Nicola Dengo 1,2 1 Istituto di Chimica della Materia Condensata e di Tecnologie per l’Energia, ICMATE-CNR, via Marzolo 1, I-35131 Padova, Italy; [email protected] (A.V.); [email protected] (N.D.) 2 Dipartimento di Scienze Chimiche, Università degli Studi di Padova and INSTM, UdR Padova, via Marzolo 1, I-35131 Padova, Italy * Correspondence: [email protected]; Tel.: +39-049-827-5736 Academic Editor: Roberto Comparelli Received: 27 December 2016; Accepted: 24 March 2017; Published: 14 April 2017 Abstract: Metal sulphides, and in particular transition metal sulphide colloids, are a broad, versatile and exciting class of inorganic compounds which deserve growing interest and attention ascribable to the functional properties that many of them display. With respect to their oxide homologues, however, they are characterised by noticeably different chemical, structural and hence functional features. Their potential applications span several ﬁelds, and in many of the foreseen applications (e.g., in bioimaging and related ﬁelds), the achievement of stable colloidal suspensions of metal sulphides is highly desirable or either an unavoidable requirement to be met. To this aim, robust functionalisation strategies should be devised, which however are, with respect to metal or metal oxides colloids, much more challenging. This has to be ascribed, inter alia, also to the still limited knowledge of the sulphides surface chemistry, particularly when comparing it to the better established, though multifaceted, oxide surface chemistry.
[Show full text]
Synthesis of Zinc Sulfide Nanocrystals and Fabrication of Nanocrystal
Materials Transactions, Vol. 45, No. 8 (2004) pp. 2650 to 2652 #2004 The Japan Institute of Metals Synthesis of Zinc Sulfide Nanocrystals and Fabrication of Nanocrystal Superlattice*1 Toshihiro Kuzuya1;*2, Yutaka Tai2, Saeki Yamamuro1, Takehiko Hihara1, Dong Liang Peng1 and Kenji Sumiyama1 1Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan 2National Institute of Advanced Industrial Science and Technology, Nagoya 463-8560, Japan We report synthesis of zinc sulfide nanocrystals (NCs) via formation of polymetallic thiolate cages. Nearly monodisperse ZnS NCs with size ranging from 2.2 to 7 nm were obtained by thermolysis of S-Zn-dodecanethiol precursors. The electron diffraction pattern of zinc sulfide NCs indicates that precipitates are wurtzite or mixture of wurtzite and zincblende. TEM observation and UV-vis spectra reveal that the growth rate of ZnS NCs considerably depends on the annealing temperature. UV-vis spectra of ZnS NCs with size smaller than 3 nm show sharp excitonic features and a large blue shift from the bulk material. The photoluminescence spectra exhibit large red shift from the absorption band edges, being attributed to electron-hole recombination by surface traps. The narrow size distribution of ZnS NCs leads to formation of ordered self-assemblies with various well-defined structures, where non-closed-packing structure is predominant. (Received April 28, 2004; Accepted June 30, 2004) Keywords: monodisperse nanocrystals, polymetallic thiolate cage, zinc sulfide, superlattice 1. Introduction semiconductors1,2) and transition metals.7,8) This process can provide nearly monodisperse ZnS NCs with size ranging Transition-metal chalcogenide nanocrystals (NCs) have from 2 to 7 nm.
[Show full text]
(II) Nitrate React to Form Aqueous Zinc Nitrate and Lead Metal. Zinc +
Chemistry Essentials Writing Equations Worksheet ANSWERS For each situation below, 1) underline the reactants, circle the products, and box symbols 2) write word equations, and 3) write standard (symbolic) equations. 1) Zinc and aqueous lead (II) nitrate react to form aqueous zinc nitrate and lead metal. Zinc + aqueous lead (II) nitrate aqueous zinc nitrate + lead metal. Zn(s) + Pb(NO3)2(aq) Zn(NO3)2(aq) + Pb(s) 2) Aqueous aluminum bromide and chlorine gas react to form aqueous aluminum chloride and bromine gas. Aqueous aluminum bromide + chlorine gas aqueous aluminum chloride + bromine gas. AlBr3(aq) + Cl2(g) AlCl3(aq) + Br2(g) 3) Aqueous sodium phosphate and aqueous calcium chloride react to form solid calcium phosphate and aqueous sodium chloride. Aqueous sodium phosphate + aqueous calcium chloride solid calcium phosphate + aqueous sodium chloride. Na3PO4(aq) + CaCl2(aq) Ca3(PO4)2(s) + NaCl(aq) 4) Potassium metal and chlorine gas combine to form solid potassium chloride. Potassium metal +chlorine gas solid potassium chloride. K(s) + Cl2(g) KCl(s) 5) Aluminum and hydrochloric acid react to form aqueous aluminum chloride and hydrogen gas. Aluminum + hydrochloric acid aqueous aluminum chloride + hydrogen gas Al(s) + HCl(aq) AlCl3(aq) + H2(g) 6) Aqueous calcium hydroxide and phosphoric acid react to form solid calcium phosphate and liquid water. Aqueous calcium hydroxide + phosphoric acid solid calcium phosphate + liquid water. Ca(OH)2(aq) + H3PO4(aq) Ca3(PO4)2(s) + H2O(l) 7) Copper and sulfuric acid react to form aqueous copper (II) sulfate and liquid water and sulfur dioxide gas. Copper + sulfuric acid aqueous copper (II) sulfate + liquid water + sulfur dioxide gas.
[Show full text]
Nomenclature Practice Sheet
Nomenclature Key C2WS6K By: Dr. Robert Belford 1) aluminum nitride AlN 24) diboron hexafluoride B2F6 2) aluminum carbonate Al2(CO3)3 25) tin (IV) fluoride SnF4 3) aluminum bicarbonate Al(HCO3)3 26) tin (II) fluoride SnF2 4) nitrogen dioxide NO2 27) tin (IV) sulfide SnS2 5) zinc sulfate ZnSO4 28) tin (II) sulfide SnS 6) zinc sulfide ZnS 29) nitrogen trichloride NCl3 7) zinc phosphate Zn3(PO4)2 30) manganese (II) sulfide MnS 8) carbon tetrachloride CCl4 31) manganese (II) sulfate MnSO4 9) sodium hydroxide NaOH 32) manganese (II) phosphate 10) barium hydroxide Ba(OH)2 Mn3(PO4)2 11) titanium (II) cyanide Ti(CN)2 33) manganese (II) nitrate Mn(NO3)2 12) cadmium iodide CdI2 34) vanadium (V) oxide V2O5 13) cadmium acetate Cd(CH3CO2)2 35) molybdenum (VI) sulfide MoS3 14) cadmium bromide CdBr2 36) silver phosphide Ag3P 15) cadmium nitrate Cd(NO3)2 37) mercury (II) oxide HgO 16) cadmium sulfide CdS 38) chromium (III) bromide CrBr3 17) phosphorus pentachloride PCl5 39) chromium (III) nitrate Cr(NO3)3 18) iron (II) sulfide FeS 40) sulfur dichloride SCl2 19) iron (II) sulfate FeSO4 41) magnesium sulfide MgS 20) iron (III) sulfate Fe2(SO4)3 42) magnesium sulfate MgSO4 21) iron (III) nitrate Fe(NO3)3 43) cobalt (III) carbonate Co2(CO3)3 22) magnesium nitride Mg3N2 44) cobalt (III) phosphide CoP 23) magnesium nitrate Mg(NO3)2 Write formulas from the following names: 1) Ni(NO3)3 nickel (III) nitrate 2) NiCl3 nickel (III) chloride Nomenclature Key C2WS6K By: Dr. Robert Belford 3) Mn(OH)2 manganese (II) hydroxide 28) Al(CN)3 aluminum cyanide 4) Hg(CN)2 mercury
[Show full text]
Chemical Word Equations (Key)
Chemistry: Chemical Word Equations KEY Directions: Write a balanced chemical equation for each of the word equations below. 1. aqueous sodium chloride reacts with aqueous lead (II) nitrate to yield a lead (II) chloride precipitate and aqueous sodium nitrate sodium chloride + lead (II) nitrate lead (II) chloride + sodium nitrate NaCl + Pb(NO3)2 PbCl2 + NaNO3 2 NaCl (aq) + Pb(NO3)2 (aq) PbCl2 (ppt) + 2 NaNO3 (aq) 2. aqueous barium nitrate reacts with sulfuric acid [H2SO4(aq)] to yield a barium sulfate precipitate and nitric acid [HNO3(aq)] barium nitrate + sulfuric acid barium sulfate + nitric acid Ba(NO3)2 + H2SO4 BaSO4 + HNO3 Ba(NO3)2 (aq) + H2SO4(aq) BaSO4 (ppt) + 2 HNO3 (aq) 3. silver nitrate reacts in solution with potassium chromate to yield a silver chromate precipitate and soluble potassium nitrate silver nitrate + potassium chromate silver chromate + potassium nitrate 2 AgNO3 (s) + K2CrO4(aq) Ag2CrO4 (ppt) + 2 KNO3 (aq) 4. solid calcium carbonate reacts with hydrochloric acid [HCl(aq)] to yield aqueous calcium chloride, carbon dioxide gas, and liquid water calcium carbonate + hydrochloric acid calcium chloride + carbon dioxide + water CaCO3 (aq) + 2 HCl(aq) CaCl2 (aq) + H2CO3 (aq) CO2 (g) + H2O (l) 5. aqueous zinc chloride reacts with dihydrogen monosulfide gas to yield a zinc sulfide precipitate and hydrochloric acid zinc chloride + dihydrogen monosulfide zinc sulfide + hydrochloric acid ZnCl2 (aq) + H2S(g) ZnS (ppt) + 2 HCl (aq) 6. magnesium nitrate reacts in solution with potassium hydroxide to yield a magnesium hydroxide precipitate and soluble potassium nitrate magnesium nitrate + potassium hydroxide magnesium hydroxide + potassium nitrate Mg(NO3)2 (s) + 2 KOH (aq) Mg(OH)2 (ppt) + 2 KNO3 (aq) 7.
[Show full text]
Photoassisted Hydrogen Production Using Visible Light and Coprecipitated Zinc Sulfide.Cntdot.Cadmium Sulfide Without a Noble Metal N
Subscriber access provided by University of Texas Libraries Photoassisted hydrogen production using visible light and coprecipitated zinc sulfide.cntdot.cadmium sulfide without a noble metal N. Kakuta, K. H. Park, M. F. Finlayson, A. Ueno, A. J. Bard, A. Campion, M. A. Fox, S. E. Webber, and J. M. White J. Phys. Chem., 1985, 89 (5), 732-734• DOI: 10.1021/j100251a002 • Publication Date (Web): 01 May 2002 Downloaded from http://pubs.acs.org on February 12, 2009 More About This Article The permalink http://dx.doi.org/10.1021/j100251a002 provides access to: • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article The Journal of Physical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 732 J. Phys. Chem. 1985, 89, 132-134 ignored since transitions to them from the So ground state are not entirely inconsistent with experiment. allowed by the symmetry selection rules.23 The best-fit parameters The So potential is relatively flat near the minimum compared for So are V2= -3980.0 cm-' and V4 = -1023.0 cm-I, and those to that of a harmonic oscillator. This shape is required to re- for SI are V2= -2054.9 cm-I and V4 = -1009.2 cm-'. These same produce the negative anharmonicity in the So(a) spacings. The potential parameters were used to calculate the 9PA-dS torsional irregular positive anharmonicity in the Sl(A) spacings requires frequencies which appear in the last column of Table 11.
[Show full text]