The first SiHi22+ Complex, Difaydridotetrakis(3-picoline)silicon Dichloride-tetrakis (chloroform)5 [H2Si(3pic)44]Cl2 · CHCl3: Formation chemical equilibria, and structural by NMR spectroscopy and single-crystal X-ray diffraction

Article abstract of DOI:10.1002/cber.19961290706

Bis(dichlorosilyl)amine reacts in chloroform solution with 2-picoline to give H₃SiCl, H₂SiCl₂, and HSiCl₃ whereas with 3-picoline the two hypervalent silicon compounds H₂SiCl₂-(3pic)₂ and [H₂Si(3pic)₄]Cl₂ ·4 CHCl₃ containing hexacoordinated Si atoms are formed. These complexes are in a chemical equilibrium with each other in chloroform solution, from which crystals of [H₂Si(3pic)₄]Cl₂ ·4 CHCl₃ could be isolated. The crystal structure of the latter was determined by single-crystal X-ray diffraction. The complex can be regarded as an "contact ion trio" of [H₂Si(3pic)₄]²⁺ and two Cl^- ions. The N→Si bond lengths, r(Si-N) = 196.9(3} and 197.5(3) pm, are similar to those found in neutral hexacoordinated Si complexes. The data obtained from a ¹H¹H ROESY experiment suggest that dissolution has no significant impact on the molecular structure of [H₂Si(3pic)₄]Cl₂ ·₄ CHCl₃. VCH Verlagsgcsellschaft mbH, 1996.