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Free keywords:
Ab initio calculations;
Flash pyrolysis;
Matrix isolation;
Silicon;
Multiple bonds;
IR spectroscopy
Abstract:
Difluorosilanethione F2Si=S (1) has been synthesized by Flash Vacuum Pyrolysis of (F3Si)2S at ≥ 500 °C and trapped in an Ar matrix. Furthermore, 1 has been obtained by co-deposition of SiS and F2/Ar and by pyrolysis of a matrix-isolated SiS2–XeF2 complex under cryogenic conditions. All six vibrational fundamentals of 1 have been observed in the matrix IR spectrum. Ab initio calculations at the MP2 and CCSD(T) levels using large basis sets have been performed. These calculations have guided the detection of 1 and the vibrational assignment. The best estimate of the structure of 1 with C2v symmetry is: r(Si=S) 191.1(1) pm, r(SiF) 156.1(1) pm, ki(FSiF) 103.3(2)°.