Structural, conformational and vibrational properties of 1,1,1-Trifluoro-N-(1,1,2,2,2-pentafluoroethyl) methanesulfinimidoyl chloride, CF3CF2NS(Cl)CF3

The structural, conformational, and configurational properties of 1,1,1-Trifluoro-N-(1,1,2,2,2-pentafluoroethyl) methanesulfinimidoyl chloride, CF3CF2NS(Cl)CF3 have been studied by vibrational spectroscopy [IR (vapor) and Raman (liquid)] and quantum chemical calculations [B3LYP, MP2 and B3PW91 levels of theory using the 6-311+G(d), 6-311+G(df) and 6-311+G(2df) basis sets]. According to these theoretical approximations, CF3CF2NS(Cl)CF3 exists in the gas phase as a mixture of a favored anticlinal form (CN bond anticlinal with respect to the CSCl bisector) with C1 symmetry and a less abundant syn conformer showing C1 symmetry as well (ΔG° ≈ 1.20 kcal mol-1). Due to the small contribution only a few corresponding vibrational modes of the syn conformer could be assigned confidently in the experimental spectra. Compared to CF3CF2NS(F)CF3, the replacement of F by Cl produces a clear change in NS bond length and the corresponding stretching frequency, without affecting the conformational properties.Fil: Robles, Norma Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Chemes, Doly María. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Heinz Oberhammer. Eberhard Karls Universität Tübingen; AlemaniaFil: Cutin, Edgardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; Argentin

Trifluoromethyl chloroformate, CIC(O)OCF3: Structure, conformation, and vibrational analysis studied by experimental and theoretical methods

The gas phase conformational properties and geometric structure of trifluoromethyl chloroformate, CIC(O)-OCF3, have been studied by vibrational spectroscopy (IR (gas), IR (matrix), and Raman (liquid)), gas electron diffraction (GED), and quantum chemical calculation (HF, B3LYP and MP2 methods with 6-311G* basis sets). The molecule exhibits only one form having Cs symmetry with synperiplanar orientation of the O-C single bond relative to the C=O double bond. If heated Ar:CIC(O)OCF3 mixtures are deposited as a matrix at 14 K, bands appear in the IR spectra which are assigned to the anti form. At room temperature, the contribution of the anti rotamer is estimated to be less than 1%. This high energy conformer is not observed in the GED experiment. The structure of solid CIC(O)OCF3 was determined by X-ray diffraction analysis from crystals obtained at low temperature, using a miniature zone melting procedure. The molecule crystallizes forming a dimeric structure belonging to the monoclinic crystal system and adopts the P21/n spatial group. Furthermore, we report the structure of the similar molecule trifluoroacetyl chloride. CF3C(O)Cl, in its crystalline phase by using the same method.Fil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Della Vedova, Carlos Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Boese, Roland. Universitat Essen; AlemaniaFil: Willner, Helge. Universitat Essen; Alemania. Bergische Universität Wuppertal; AlemaniaFil: Oberhammer, Heinz. Eberhard Karls Universität Tübingen; Alemani

On the search of the influence of substituents in the structural and vibrational properties of p-substituted sulfinylanilines: Study of p-trifluoromethylsulfinylaniline

The study of substitution effects on the structural and vibrational properties of para substituted sulfinylanilines proceeds a step forward with the study of p-trifluoromethylsulfinylaniline, synthesized and characterized by NMR, Raman, FTIR and mass spectra. The experimental spectra were compared and analyzed taking into account theoretical spectra obtained with quantum chemical calculations at different levels of theory. The spectroscopic results reveal the presence of a single form of this molecule which, according to the calculated molecular structure, possesses the NSO group coplanar with the ring plane. In addition, the syn conformation of the NSO group is also derived from both, experimental and theoretical data. The presence of the CF 3 group in the para position of the aromatic ring influences the properties of the N[dbnd]S[dbnd]O group, with the N[dbnd]S bond more strongly affected than the S[dbnd]O bond compared to results reported for other para substituted sulfinylanilines.Fil: Chemes, Doly María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Cutin, Edgardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Alvarez, Rosa Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Robles, Norma Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología; ArgentinaFil: Oberhammer, Heinz. Universität Tübingen; Alemani

Trifluoromethanesulfenyl acetate, CF3S-OC(O)CH3, and trifluoromethanesulfenyl trifluoroacetate, CF3S-OC(O)CF3: Unexpected conformational properties

Structural and conformational properties of two sulfenyl derivatives, trifluoromethanesulfenyl acetate, CF3S-OC(O)CH3 (1), and trifluoromethanesulfenyl trifluoroacetate, CF3S-OC(O)CF3 (2), were determined by gas electron diffraction, vibrational spectroscopy, in particular with IR (matrix) spectroscopy, which includes photochemical studies, and by quantum chemical calculations. Both compounds exist in the gas phase as a mixture of two conformera, with the prevailing component possessing a gauche structure around the S-O bond. The minor form, 15(5)% in 1 and 11(5)% in 2 according to IR(matrix) spectra, possesses an unexpected trans structure around the S-O bond. The C=O bond of the acetyl group is oriented syn with respect to the S-O bond in both conformers. UV-visible broad band irradiation of 1 and 2 isolated in inert gas matrixes causes various changes to occur. Conformational randomization clearly takes place in 2 with simultaneous formation of CF 3SCF3. For 1 the only reaction channel detected leads to the formation of CH3SCF3 with the consequent extrusion of CO2. Quantum chemical calculations (B3LYP/6-31G* and MP2 with 6-31G* and 6-311G(2df,pd) basis sets) confirm the existence of a stable trans conformer. The calculations reproduce the conformational properties for both compounds qualitatively correct with the exception of the B3LYP method for compound 2 which predicts the trans form to be prevailing, in contrast to the experiment.Fil: Ulic, Sonia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Kosma, Areti. Eberhard Karls Universität Tübingen; AlemaniaFil: Leibold, Christiane. Eberhard Karls Universität Tübingen; AlemaniaFil: Della Vedova, Carlos Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Willner, Helge. Wuppertal Institut Für Klima, Umwelt, Energie Ggmbh.; AlemaniaFil: Oberhammer, Heinz. Eberhard Karls Universität Tübingen; Alemani

Synthesis, characterization and vibrational studies of p-chlorosulfinylaniline

p-Cholorosulfinylaniline was prepared by the reaction of p-chloroaniline and SOCl2. The structural, conformational and configurational properties of the obtained liquid compound were studied by Raman and infrared spectroscopy in the liquid state. The assignment of the vibrational spectra was carried out with the help of data obtained by quantum chemical calculations at the harmonic oscillator approximation and using anharmonic vibrational self-consistent field (VSCF) method as well. The 1H and 13C NMR chemical shifts of the molecule were calculated by Gauge including orbital (GIAO) method (DFT/B3LYP approximation using 6-311 + G (df), 6-311++G (df,pd) and cc-pVTZ basis sets) and compared to the experimental values. Natural Bond Orbital analysis provides an explanation of the stability of the molecule and its electronic properties upon charge delocalization.Fil: Chemes, Doly María. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Alonso de Armiño, Diego Javier. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Cutin, Edgardo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Oberhammer, Heinz. Universitat Tübingen; AlemaniaFil: Robles, Norma Lis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentin

Anomeric and mesoneric effects in methoxycarbonylsulfenyl chloride, CH3OC(O)SCl. An experimental and theoretical study

The molecular structure and conformational properties of methoxycarbonylsulfenyl chloride, CH3OC(O)SCl, were determinated in the gas and solid phases by gas electron diffraction, low-temperature X-ray diffraction, and vibrational spectroscopy. Furthermore, quantum chemical calculations were performed. Experimental and theoretical methods result in structures with a planar C−O−C(O)−S−Cl skeleton. The electron diffraction intensities are reproduced best with a mixture of 72(8)% syn and 28(8)% anti conformers (S−Cl bond synperiplanar/antiperiplanar with respect to CdO bond) and the O−CH3 bond synperiplanar with respect to the CdO bond. The syn form is the preferred form and becomes the exclusive form in the crystalline solid at low temperature. This experimental result is reproduced very well by Hartree−Fock approximation and by density functional theory at different levels of theory but not by the MP2/6-311G* method, which overestimates the value of ∆G° between the syn and anti conformers. The results are discussed in terms of anomeric effects and a natural bond orbital (NBO) calculation. Photolysis of matrixisolated CH3OC(O)SCl with broad-band UV−visible irradiation produces an interconversion of the conformers, and the concomitant decomposition leads to formation of OCS and CO molecules.Fil: Erben, Mauricio Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Della Vedova, Carlos Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Romano, Rosana Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Boese, Roland. Universitat Essen; AlemaniaFil: Oberhammer, Heinz. Eberhard Karls Universität Tübingen; AlemaniaFil: Willner, Helge. Universitat Essen; AlemaniaFil: Sala, Oswaldo. Universidade de Sao Paulo; Brasi