Conformational properties of F₂SNCF₂NSF₂ and F₂SNCF₂NS(O)F₂: Vibrational spectra and quantum chemical calculations

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• 作者：Andrea Flores Antognini^a ; Norma L. Robles^a ; Edgardo H. Cutin^a ;   ; ^{cutin@fbqf.unt.edu.ar} ; Heinz Oberhammer^b ;   ; ^{heinzoberhammer@uni-tuebingen.de}
• 关键词：Bis(N-difluorosulfurimino)difluoromethane ; N-difluorosulfurimino-N-diflurosulfuroxyimino difluoromethane ; Conformational properties ; Vibrational spectra ; Quantum chemical calculations
• 刊名：Journal of Molecular Structure
• 出版年：2011
• 出版时间：14 September 2011
• 年：2011
• 卷：1002
• 期：1-3
• 页码：1-9
• 全文大小：864 K

文摘

The structural and conformational properties of F₂SNCF₂NSF₂ and F₂SNCF₂NS(O)F₂ were studied by vibrational spectroscopy (IR(gas) and Raman(liquid)) and by quantum chemical calculations, using B3LYP and MP2 methods with small and large basis sets. Since the SF₂ and S(O)F₂ groups can adopt syn (s) or anti (a) position (syn/anti of the FSF bisector with respect to the adjacent NC bond) and the orientation around the two NC bonds can be trans (t) or gauche (g), a large number of possible conformers is expected. In the case of F₂SNCF₂NSF₂ calculations with large basis sets predict the presence of a single conformer with both SF₂ groups in syn position and gauche orientation around both NC bonds (s¨Cg¨Cg¨Cs conformer). This is confirmed by the vibrational spectra. For F₂SNCF₂NS(O)F₂ analysis of the vibrational spectra in combination with the quantum chemical calculations suggests the predominance of the s¨Cg¨Ct¨Cs conformer, i.e. syn position of SF₂ and S(O)F₂ groups, gauche orientation around one NC bond and trans orientation around the other NC bond, and the presence of a smaller amounts of the s¨Ct¨Cg¨Cs and s¨Cg¨Cg¨Cs conformers.