Branched Star-Type Polysilyllithium Compounds: The Effects of ß-Silyl Substitution and of Complexation on Their Molecular Structure.

It was fortunate that the first extended branched polysilyl anion (Me3 SiMe2 Si)3 Si(-) could be crystallographically characterized in two forms-as the THF complex 1 and as the dimer 2. Comparison with the analogous (Me3 Si)3 SiLi systems 3 and 4 shows that ß-Me3 Si substitution and complexation by THF elongate the Si-Li distance by 0.09-0.14 Å and 0.04-0.07 Å, respectively.

The Synthesis and Molecular Structure of the First Two-Coordinate, Dinuclear σ-Bonded Mercury(I) RHgHgR Compound.

A linear Si-Hg-Hg-Si arrangement and a Hg-Hg distance of 265.69 pm are exhibited by the first two-coordinate, dinuclear σ-bonded organomercury(I) compound 1. It was formed unexpectedly in the reaction of two equivalents of the silane (Me3 SiMe2 Si)3 SiH with tBu2 Hg. In contrast if the reagents are allowed to react in a 1:1 ratio the expected mercury(II) compound (Me3 SiMe2 Si)3 SiHgtBu is obtained.