Theoretical Calculation of the Rotational Barrier, Valence Force Constants and Experimental Electronic Spectrum of Chlorocarbonylsulphenyl Chloride (ClC(O)SCl)

The rotational barrier around the C-S bond in chlorocarbonylsulphenyl chloride (CIC(O)SCI)is investigated using the INDO, PCILO and GAUSSIAN-70techniques. The results confirm the existence of planar cis and trans conformers with a higher stability of the latter, as suggested by previous vibrational results. The origin of the rotational barrier is due to an increase of electronic delocalization as demonstrated by INDO and PCILO calculations. The optimized geometrical parameters obtained by means of the ab-initio method with an STO-3G basis set are reported for the different conformers. Valence force constants have been calculated and the values obtained compare fairly well with the results from a previous normaI coordinate calculation. The experimental electronic spectrum, maximum molar absortivities, oscillator strengths and atentative assignrnent of its electronic bands, are reported

Theoretical Calculation of the Rotational Barrier, Valence Force Constants and Experimental Electronic Spectrum of Chlorocarbonylsulphenyl Chloride (ClC(O)SCl)

The rotational barrier around the C-S bond in chlorocarbonylsulphenyl chloride (CIC(O)SCI)is investigated using the INDO, PCILO and GAUSSIAN-70techniques. The results confirm the existence of planar cis and trans conformers with a higher stability of the latter, as suggested by previous vibrational results. The origin of the rotational barrier is due to an increase of electronic delocalization as demonstrated by INDO and PCILO calculations. The optimized geometrical parameters obtained by means of the ab-initio method with an STO-3G basis set are reported for the different conformers. Valence force constants have been calculated and the values obtained compare fairly well with the results from a previous normaI coordinate calculation. The experimental electronic spectrum, maximum molar absortivities, oscillator strengths and atentative assignrnent of its electronic bands, are reported

Conformational Properties of Ethyl- and 2,2,2-Trifluoroethyl Thionitrites, (CX3CH2SNO, X = H and F)

Canneva A, Della Vedova CO, Mitzel NW, Erben MF. Conformational Properties of Ethyl- and 2,2,2-Trifluoroethyl Thionitrites, (CX3CH2SNO, X = H and F). The Journal of Physical Chemistry A. 2015;119(9):1524-1533.The simple 2,2,2-trifluoroethyl thionitrite molecule, CF3CH2SNO, has been prepared in good yield for the first time using CF3CH2SH and NOCl in slight excess. The vapor pressure of the red-brown compound CF3CH2SNO follows, in the temperature range between 226 and 268 K, the equation log p = 12.0-3881/T (p/bar, T/K), and its extrapolated boiling point reaches 51 degrees C. Its structural and conformational properties have been compared with the ethyl thionitrite analogue, CH3CH2SNO. The FTIR spectra of the vapor of both thionitrites show the presence of bands with well-defined contours, allowing for a detailed conformational analysis and vibrational assignment on the basis of a normal coordinate analysis. The conformational space of both thionitrite derivatives has also been studied by using the DFT and MP2(full) level of theory with extended basis sets [6-311+G(2df) and cc-pVTZ]. The overall evaluation of the experimental and theoretical results suggests the existence of a mixture of two conformers at room temperature. The relative abundance of the most stable syn form (N=O double bond syn with respect to the C-S single bond) has been estimated to be ca. 79 and 75% for CF3CH2SNO and CH3CH2SNO, respectively

Spectroscopic and structural studies of bis[isopropoxy(thiocarbonyl)]sulfide, [(CH(3))(2)CHOC(S)](2)S

Structural and conformational properties of the molecule bis[isopropoxy(thiocarbonyl)]sulfide, [(CH(3))(2)CHOC(S)](2)S, have been studied by vibrational spectroscopy (IR and Raman) and quantum chemical calculations (HF and B3LYP with 6-31+G* basis sets). The crystal and molecular structure of the title compound was determined by X-ray diffraction methods. It crystallizes in the monoclinic C2/c space group with a = 8.4007(4), b = 13.5936(5), c = 10.3648(5) angstrom, beta = 106.024(4)degrees and Z = 4 molecules per unit cell. The molecules are sited on a crystallographic twofold axis passing through the sulphide atom and arranged in layers perpendicular to the b-axis. The solid state IR and Raman spectra of the compound give no sign of any other rotamer. (C) 2009 Elsevier B.V. All rights reserved.Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET)Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)[PIP 4695]Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (CIC), ArgentinaComisión de Investigaciones Científicas Provincia de Buenos Aires (CIC) - ArgentinaAgencia Nacional Cientifica y Tecnologica[PICT 33878]Agencia Nacional Cientifica y TecnologicaFacultad de Ciencias ExactasFacultad de Ciencias ExactasUniversidad Nacional de La PlataUniversidad Nacional de La PlataFAPESP of BrazilFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Deutscher Akademischer Austauschdienst (DAAD)Deutscher Akademischer Austausch Dienst (DAAD)CONICETConsejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET

The Structure and Conformation of (CH3)(3)CSNO

Canneva A, Erben MF, Romano RM, et al. The Structure and Conformation of (CH3)(3)CSNO. Chemistry - A European Journal. 2015;21(29):10436-10442.The gas-phase molecular structure of (CH3)(3)CSNO was investigated by using electron diffraction, allowing the first experimental geometrical parameters for an S-nitrosothiol species to be elucidated. Depending on the orientation of the SNO group, two conformers (anti and syn) are identified in the vapor of (CH3)(3)CSNO at room temperature, the syn conformer being less abundant. The conformational landscape is further scrutinized by using vibrational spectroscopy techniques, including gas-phase and matrix-isolation IR spectroscopy, resulting in a contribution of ca. 80:20 for the anti:syn abundance ratio, in good agreement with the computed value at the MP2(full)/cc-pVTZ level of approximation. The UV/Vis and resonance Raman spectra also show the occurrence of the conformational equilibrium in the liquid phase, with a moderate post-resonance Raman signature associated with the 350nm electronic absorption

Structure, conformational properties and matrix photochemistry ofS-(tert-butyl)trifluorothioacetate CF3C(O)SC(CH3)(3)

Cayon VM, Erben MF, Romano RM, Stammler H-G, Mitzel NW, Della Vedova CO. Structure, conformational properties and matrix photochemistry ofS-(tert-butyl)trifluorothioacetate CF3C(O)SC(CH3)(3). New Journal of Chemistry. 2020;44(34):14568-14577.S-(tert-Butyl)trifluorothioacetate, CF3C(O)SC(CH3)(3), was prepared by condensation of CF3C(O)Cl and (CH3)(3)CSH under vacuum conditions. The compound was isolated and properly characterized by using vibrational (infrared and Raman), UV-Vis and multinuclear NMR spectroscopy techniques and by mass spectrometry. The conformational preference and its crystal structure have been determined by means of FTIR spectroscopy (gas phase and Ar-matrix) and by X-ray diffraction. A charge density determination of X-ray diffraction (XRD) data of single crystals formed byin situcrystallization reveals the presence of solely a synperiplanar conformation (synform orientation of the C=O double bond with respect to the S-C single bond) belonging to theC(s)point group of symmetry. Intermolecular C=OMIDLINE HORIZONTAL ELLIPSISC=O and C=OMIDLINE HORIZONTAL ELLIPSISH-C interactions were detected in the crystal. Quantum-chemical calculations at the B3LYP/cc-pVTZ level of approximation reproduce the conformational preference and the experimental geometrical parameters fairly well. Vibrational information was obtained from Ar-matrix isolation FTIR and liquid Raman spectroscopy. Additionally, CF3C(O)SC(CH3)(3)isolated in solid Ar atca.15 K was irradiated with UV-visible broadband light (200 <= lambda <= 800 nm) and its photolysis products CF3SC(CH3)(3)and CO were detected

Spectroscopic and structural studies on phenyl and pentafluorophenyl trifluorothioacetate, and pentafluorophenyl trifluoroacetate, CF3C(O)SC6H5, CF3C(O)SC6F5 and CF3C(O)OC6F5

Cayon VM, Erben MF, Romano RM, Stammler H-G, Mitzel NW, Della Vedova CO. Spectroscopic and structural studies on phenyl and pentafluorophenyl trifluorothioacetate, and pentafluorophenyl trifluoroacetate, CF3C(O)SC6H5, CF3C(O)SC6F5 and CF3C(O)OC6F5. Physical Chemistry, Chemical Physics. 2023.Phenyl and pentafluorophenyl trifluorothioacetate, CF3C(O)SC6H5 and CF3C(O)SC6F5, were prepared by condensation of CF3C(O)Cl and the corresponding mercaptan RSH under vacuum conditions. The compounds were isolated and properly characterized by using infrared spectroscopy, UV-Vis, multinuclear NMR spectroscopy techniques and by mass spectrometry. The crystal structures have been determined for both CF3C(O)SC6H5 and according to the best of our knowledge the not yet reported in the literature CF3C(O)SC6F5 species. The conformational preferences of the three title species were also determined by means of FTIR spectroscopy. In the case of CF3C(O)OC6F5, the FTIR spectrum was also measured in an Ar-matrix and a subsequent photochemical study was performed. The main stable photoproduct found, beside CO, was the ether C6F5OCF3. Quantum-chemical calculations were used to determine the conformational preferences and complement the experimental structure parameters as well as to interpret the UV-Vis spectra determined for the three species under study. As a result of all these experimental determinations complemented with computational calculations, it can be affirmed that the title compounds present a single syn conformation in the analyzed phases (syn with respect to the CO double bond and the opposite C-chalcogen single bond). This finding reconfirms the syn conformational transferability found so far for both thioesters and esters, a result that is closely related to the properties of these families in biological processes