Calculations of the infrared and Raman spectra of simple thiols and thiol–water complexes

Abstract

ABSTRACT:The frequencies and intensities of infrared and Raman spectra of H 2 S, CH 3 SH, CH 3 CH 2 SH, and CH 2 ¼ ¼CHCH 2 SH, isolated and complexed with one water molecule acting as a proton acceptor were calculated at the ab initio and density functional level. Hartree-Fock, MP2 and CCSD(T) methods were used both for the geometry optimization and spectra calculations at the molecular orbital level. The B3LYP, PBE0, and M06 exchange-correlation potentials were employed to calculate the same properties at the DFT level. Both Pople basis sets, 6-31þG(d) and 6-311þþG(3df,2pd), and Dunning basis sets, aug-cc-pVTZ and aug-cc-pVQZ, were used. SH and CS frequency shifts upon water complexation were studied, and a discussion is performed on the expected relation between the CH and CS Raman activities, in view of their usefulness for studies in protein chemistry. Scaling factors for the vibrational frequencies were obtained for all the combination of methods and basis sets, and shown to be completely similar to the ones present in the literature when available. Scaling factors for the M06 method are presented for the first time with these basis sets.

Influence of solvent on the morphology and photocatalytic properties of ZnS decorated CeO2 nanoparticles

“…In fact, only a few vibrators are possible in this spectral range, e.g., S-H stretching vibration occurs at $2500-2600 cm À1 in H 2 S and thiols. 63,64 Therefore, this vibration was tentatively assigned to weak S-H(OH) bond stretching present in species such as ZnS-H 2 O that is consistent with the significant reduction in frequency observed. The other band at $1250 cm À1 that displayed similar behaviors would correspond to the same vibrator.…”

Variable-temperature X-ray diffraction study of structural parameters of NH---S hydrogen bonds in triethylammonium and pyridinium silanethiolates

“…Stretching vibrations of the thiol group S-H are observed within the range 2500 to 2600 cm À1 (Baranowska et al, 2012;Biswal et al, 2010;Kieninger & Ventura, 2011;Dołęga et al, 2012;Yablonskii et al, 1973;Rozenberg et al, 1999;Becker et al, 1982;Wojnowski & Herman, 1976;Mielcarek & Dołę ga, 2016). We observe this band for TDST at 2556 cm À1 (Fig.…”

“…Although research is focused on the more common hydrogen bonds with O and N atoms as donor-acceptor partners, the number of studies on weaker hydrogen bonds with sulfur is increasing (e.g. Biswal et al, 2010;Kieninger &Ventura, 2011;Solimannejad et al, 2011). Because of the importance of NHÁ Á ÁS hydrogen bonding in biological systems, a better understanding of these interactions at the molecular level is crucial (Biswal & Wategaonkar, 2009).…”

Healable dual organic–inorganic crosslinked sol–gel based polymers: Crosslinking density and tetrasulfide content effect

“…A similar dependence has been observed in proteins but has never been reported for self‐healing polymers. The increase in S–S bond content at elevated temperatures can be due to an accelerated oxidation of free thiol groups which their presence in the polymer network was confirmed by Raman spectroscopy ( ʊ S–S = 2570 cm −1 ) at all the tested temperatures.…”

“…Four spectral bands were chosen to evaluate the occurring chemical reactions: one for S–S stretching ( ʊ S–S = 510 cm −1 ), one for C=O stretching ( ʊ C=O = 1743 cm −1 ), one for S–H stretching ( ʊ S–H = 2570 cm −1 ), and one to serve as the internal standard ( ʊ C–C = 1186 cm −1 ) . The spectra were baseline corrected and the peak area ratios (A ʊ S–S /A ʊ C–C ) were calculated to determine the S–S bond content.…”