An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

This is a study of structure – reactivity relationship of clomesone.

Methyl trifluoromethanethiosulfonate, CF3SO2SCH3, was synthesized and characterized by 13C NMR, 19F NMR, and vibrational spectroscopy. This structural study was supported by MP2 and DFT (B3LYP and MPW1PW91) calculations, which revealed a strong dependence of the theoretical structure on the polarization of the basis set. Theoretical data indicate that only one conformer, gauche, is predicted by rotating around the S–S bond. This conformational preference was studied using the total energy scheme and natural bond orbital partition scheme. These results evidence that electron delocalization and especially LP S→σ∗ C(1)-S interactions play an interesting role in the reactivity-structure connection of oxoesters and thioesters.Gas and liquid infrared and liquid Raman spectra were recorded and assigned. The experimental vibrational data along with theoretical force constants (B3LYP) were used to define a scaled quantum mechanical force field, which enabled the reproduction of the measured frequencies with a final root-mean-square deviation of 8.06cm−1.

The experimental and theoretical study on the molecular and vibrational analysis of CF3CH2CH2SO2Cl, 3,3,3-trifluoropropane-1-sulfonyl chloride is presented. The IR and Raman spectra were recorded in liquid state and compared with the spectral data obtained by the DFT/B3LYP method usingthe6-311G(3df) basis set. The influence of hyperconjugation effects of the lone pairs (LP) chlorine atom on the vibrational behavior of the group SO2 was determined. The TD-DFT approach was applied to assign the electronic transitions observed in the UV–visible spectrum.

Vibrational and electronic spectra for 1-benzyl-3-(2-furoyl) thiourea were calculated by using density functional method (B3LYP) with different basis sets. The complete assignment of all vibrational modes was performed on basis of the calculated frequencies and comparing with the reported IR and Raman spectra for that thiourea derivative. UV-visible absorption spectra of the compound dissolved in methanol were recorded and analyzed using time dependent density functional theory (TD-DFT). The calculated values for the geometrical parameters of the title compound are consistent with the ones reported from XRD studies. The stability of the molecule, related to hyper-conjugative interactions, and electron delocalization were evaluated using natural bond orbital (NBO) analysis. Intra-molecular interactions were studied by AIM approach. The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. Molecular electrostatic potential map was performed by the DFT method.

The aim of this work is to evaluate the vibrational and structural properties of l-cysteine ethyl ester hydrochloride (CE), and its electronic behavior mainly in relation to the action of the thiol and amine groups at different degrees of solvation. The crystal structure of CE was determined at room temperature by X-ray diffraction methods. Infrared and Raman spectra were collected to compare the behavior of different functional groups in the molecule, both in the solid phase and in aqueous solution. Its UV and circular dichroism spectra were also measured in aqueous solution. The influence of an aqueous environment on the CE spectra was simulated by means of implicit (polarizable continuum model) and explicit (molecular dynamics, solute-solvent clusters) methods. Calculations in explicit and continuous solvent are of interest to explain the behavior of bioavailable sites in this medium. The study was completed by natural bond orbital analysis to determine the presence of hyperconjugative interactions.

The molecular structure of trimethylsilyl trichloroacetate, CCI3C(O)OSi(CH3)(3), was determined by ab initio (MP2) and DFT calculations using 6-31G(d), 6-311G(d,p), 6-311++G(d,p) and 6-311++G(3df,3pd) basis sets. The infrared and Raman spectra for the liquid phase were also recorded and the bands observed assigned to the vibrational normal modes. The study was completed using natural bond orbital (NBO) analysis and atoms in molecules (AIM) calculations. The comparison between the calculated molecular geometrical parameters, conformation and vibrational properties and those measured for CX3C(O)OR [X = F, Cl and R = CH3, Si(CH3)(3)] was of particular interest in order to check the behavior of the C = O and C-O with respect to the different substitutions. The experimental vibrational data, along with calculated theoretical force constants, were used to define a scaled quantum mechanical force field for the target system that enabled us to estimate the measured wavenumbers with a final root-mean-square deviation of 8.92 cm(-1). (c) 2012 Elsevier B.V. All rights reserved.

The molecular structure of trimethylsilyl trichloroacetate, CCl 3 C(O)OSi(CH 3 ) 3 , was determined by ab initio (MP2) and DFT calculations using 6-31G(d), 6-311G(d,p), 6-311++G(d,p) and 6-311++G(3df,3pd) basis sets.The infrared and Raman spectra for the liquid phase were also recorded and the bands observed assigned to the vibrational normal modes.The study was completed using natural bond orbital (NBO) analysis and atoms in molecules (AIM) calculations.The comparison between the calculated molecular geometrical parameters, conformation and vibrational properties and those measured for CX 3 C(O)OR [X = F, Cl and R = CH 3 , Si(CH 3 ) 3 ] was of particular interest in order to check the behavior of the C O and C O with respect to the different substitutions.The experimental vibrational data, along with calculated theoretical force constants, were used to define a scaled quantum mechanical force field for the target system that enabled us to estimate the measured wavenumbers with a final root-mean-square deviation of 8.92 cm -1 .

Bis (trifluoromethyl) sulfone, CF3SO2CF3, was obtained as a byproduct in the synthesis of CF3SO2SCF3. The compound was characterized by infrared and Raman spectroscopy as well quantum chemical calculations. Quantum mechanical calculations indicate the possible existence of two conformers symmetrically equivalent with C2 symmetry. The preference for the staggered form was studied using the total energy scheme and the natural bond orbital (NBO) partition scheme. Additionally, the total potential energy was deconvoluted using a sixfold decomposition in terms of a Fourier-type expansion, showing that the hyperconjugative effect was dominant in stabilizing the staggered conformer. Infrared and Raman spectra of CF3SO2CF3 were obtained. Harmonic vibrational wavenumbers and a scaled force field were calculated, leading to a final root mean-square deviation of 7.8 cm−1 when comparing experimental and calculated wavenumbers.

Trifluoromethyl trifluoromethanethiosulfonate, CF3SO2SCF3 was characterized by 13C NMR, 19F NMR, and vibrational spectroscopy. Infrared spectra of CF3SO2SCF3 were obtained for the gaseous and liquid phases, while the Raman spectrum was recorded for the liquid phase. The experimental data were complemented with quantum chemical calculations. Both experimental and theoretical data indicate that only one conformer, gauche, is possible by rotating around the S–S bond. This conformational preference was studied using the total energy scheme and natural bond orbital partition scheme. These results evidence that electron delocalization and especially LP Y(Y=S, O)→σ* S(6)O(4,5) and LP O(4,5)→σ* S(6)Y interactions play an interesting role in the reactivity of oxoesters and thioesters.

Trichloromethyl trifluoromethanesulphonate, CF3SO2OCCl3, was prepared by quantitative reaction between Ag(CF3SO2O) and BrCCl3. The conformational and structural properties of the gaseous molecule were studied by vibrational spectroscopy (IR (gas, liquid), Raman (liquid) and quantum chemical calculations (DFT and ab initio methods)).Theoretical and experimental vibrational results evidenced the presence of a single conformer with C-1 symmetry. This result is in agreement with the adopted geometry of covalent sulphonates. The conformational preference was studied using the total energy scheme and natural bond orbital partition scheme. Additionally, the total potential-energy has been deconvoluted using six fold decomposition in terms of a Fourier-type expansion. (C) 2010 Elsevier BY. All rights reserved.