- VIBRATIONAL SPECTRA AND NORMAL COORDINATE ANALYSIS OF METHYL THIONITRITE AND ISOTOPIC ANALOGS
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The observed gas-phase IR frequencies for forty-four fundamentals of methyl thionitrite (CH3SNO) and its d3-, 13C-, and 15N-substituted analogs have been used to calculate a nineteen-parameter symmetry valence force field.The final refinement resulted in an average error of less than 4 cm-1 (ca. 0.5percent) between the calculated and observed frequencies for the four isotopomers.Contrary to earlier reports, relative intensities, isotopic frequency shifts, as well as the calculated potential-energy distribution, all support the assignment of ν(CS) to a higher frequency than that of ν(SN).For the normal molecule ν(CS) is observed as a weak band at 735 cm-1; by contrast, ν(SN) absorbs strongly at 646 cm-1.The NO stretching fundamental occurs at 1535 cm-1 in the gas-phase spectrum of the unsubstituted molecule but shifts to 1507 cm-1 when 15N replaces the normal isotope.The five fundamental bands associated with the skeletal vibrations of CH3SNO are compared with the analogous absorptions in the spectra of CF3SNO and CH3ONO.
- Byler, D. Michael,Susi, Heino
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- Thioester hydrolysis promoted by a mononuclear zinc complex
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The mononuclear zinc complex [(bpta)Zn](CIO4)2 · 0.5H2O promotes the hydrolysis of the thioester PhCH(OH)C(O)SCD3 when dissolved in CH3CN:H2O (50:50 buffered at pH 9.0). This reaction results in the formation of a mixture of CD3SH and a zinc thiolate complex, the latter of which can be protonated to generate additional CD3SH. Kinetic studies revealed an overall second-order reaction with an activation energy that is similar to that found for aqueous OH- promoted thioester hydrolysis. These studies represent the first investigation of chemistry relevant to that occurring in the monozinc-containing form of human glyoxalase II.
- Danford, James J.,Arif, Atta M.,Berreau, Lisa M.
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- EPR spectra and spin density distribution of O, S-dimethyl 4,4-dithioterephthalate radical anions
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The preparation of O-methyl S-trideuteromethyl 4,4-dithioterephthalate and S-methyl O-trideuteromethyl 4,4-dithioterephthalate is described. The EPR spectra of the corresponding radical anions are measured. Comparison with the spectrum of O,S-dimethyl 4,4
- Voss, Juergen,Buddensiek, Dirk,Rosenboom, Jan Folkert
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experimental part
p. 382 - 391
(2012/04/10)
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