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RESEARCH PRODUCT

Experimental Investigations and ab Initio Studies on Hexacoordinated Complexes of Dichlorosilane

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Dichlorosilane, SiH2Cl2, forms two different kinds of coordination compounds with pyridine and 3-picoline:  the simple adduct trans-SiH2Cl2(L)2 and the ionic complex [SiH2(L)4]Cl2·4CHCl3 (L = pyridine, 3-picoline). The adducts trans-SiH2Cl2(py)2, 1, and trans-SiH2Cl2(3pic)2, 2, form directly from the reaction of bis(dichlorosilyl)methylamine, NMe(SiHCl2)2 with pyridine (py), and 3-picoline (3pic). Reaction of 1 with an excess of pyridine in chloroform yielded [SiH2(py)4]Cl2·4CHCl3, 3. The molecular and crystal structures of 1−3 were investigated by single-crystal X-ray diffraction. The Si atoms of all three compounds are hexacoordinated and lie on centers of inversion. The basic structural parameters are the following:  1 (monoclinic, C2/c):  Si−N 196.9(1) pm, Si−Cl 228.8(1) pm; N−Si−Cl 90.0(1)°, C−N−C 119.0(2)o; Cl−Si−N−C 102.4(1)°. 2 (triclinic, P1):  Si−N 197.5(1) pm, Si−Cl 229.2(1) pm; N−Si−Cl 90.3(1)°, C−N−C 118.8(1)°; Cl−Si−N−C 101.2(1)°. 3 (monoclinic, C2/m):  Si−N 196.2(4) and 197.0(4) pm, Si···C...