Fluoroformyl Trifluoroacetyl Disulfide, FC(O)SSC(O)CF3: Synthesis, Structure in Solid and Gaseous States, and Conformational Properties
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- 作者：Mauricio F. Erben ; Carlos O. Della Vé ; dova ; Helge Willner ; Frank Trautner ; Heinz Oberhammer ; and Ronald Boese
- 刊名：Inorganic Chemistry
- 出版年：2005
- 出版时间：October 3, 2005
- 年：2005
- 卷：44
- 期：20
- 页码：7070 - 7077
- 全文大小：153K
- 年卷期：v.44,no.20(October 3, 2005)
- ISSN：1520-510X
文摘
Fluoroformyl trifluoroacetyl disulfide, FC(O)SSC(O)CF3, is prepared by quantitative reaction between FC(O)SCland CF3C(O)SH. The conformational properties and geometric structure of the gaseous molecule have been studiedby vibrational spectroscopy (IR(gas), Raman(liquid), IR(matrix)), gas electron diffraction (GED), and quantum chemicalcalculations (B3LYP and MP2 methods). The disulfide bond length derived from the GED analysis amounts 2.023(3)Å, and the dihedral angle around this bond, 
(CS-SC), is 77.7(21)
, being the smallest dihedral angle measuredfor noncyclic disulfides in the gas phase. The compound exhibits a conformational equilibrium at room temperaturehaving the most stable form C1 symmetry with a synperiplanar (sp-sp) orientation of both carbonyl groups withrespect to the disulfide bond. A second form was observed in IR spectra of the Ar matrix isolated compound atcryogenic temperatures, corresponding to a conformer that possess the carbonyl bond of the FC(O) moiety inantiperiplanar position with respect to the S-S single bond (ap-sp). A 
H = 
- 
= 1.34(11) kcal/mol has been determined by IR(matrix) spectroscopy. The structure of single crystal of FC(O)SSC(O)CF3 wasdeterminate by X-ray diffraction analysis at low temperature using a miniature zone melting procedure. The crystallinesolid (monoclinic, P21/n, a = 5.240(4)Å, b = 23.319(17)Å, c = 6.196(4)Å, 
= 113.14(3)) consists exclusivelyof the (sp-sp) conformation. The geometrical parameters agree with those obtained for the molecule in the gasphase.
(CS-SC), is 77.7(21), being the smallest dihedral angle measuredfor noncyclic disulfides in the gas phase. The compound exhibits a conformational equilibrium at room temperaturehaving the most stable form C1 symmetry with a synperiplanar (sp-sp) orientation of both carbonyl groups withrespect to the disulfide bond. A second form was observed in IR spectra of the Ar matrix isolated compound atcryogenic temperatures, corresponding to a conformer that possess the carbonyl bond of the FC(O) moiety inantiperiplanar position with respect to the S-S single bond (ap-sp). A H = - = 1.34(11) kcal/mol has been determined by IR(matrix) spectroscopy. The structure of single crystal of FC(O)SSC(O)CF3 wasdeterminate by X-ray diffraction analysis at low temperature using a miniature zone melting procedure. The crystallinesolid (monoclinic, P21/n, a = 5.240(4)Å, b = 23.319(17)Å, c = 6.196(4)Å, = 113.14(3)) consists exclusivelyof the (sp-sp) conformation. The geometrical parameters agree with those obtained for the molecule in the gasphase.