SYNTHESIS AND CHARACTERIZATION OF TETRAKIS(TRIHALOGERMYL)METHANES - MOLECULES CONTAINING STERICALLY STRAINED CARBON CENTERS

Dihalogermylene complexes, GeX(2) . dioxane (X = Cl, Pr), undergo comp lete insertion into CBr4 to afford the sterically crowded tetrakis(tri halogermyl)methanes, (BrCl2Ge)(4)C (1) and (Br3Ge)(4)C (2). Compounds 1 and 2 display physical properties and IR spectra indicative of highl y symmetric molecules containing a tetrahedral core of group IVA atoms . An X-ray analysis of 2 indicates that carbon centers can exist in st erically strained germanium environments (e.g. the cubic lattice of Ge 1-xCx alloys) without fragmenting. Both 1 and 2 react with LiAlH4 to p roduce the reduction products (H3Ge)(4)C (3) and (H3Ge)(3)CH (4), thus completing the family of silyl- and germylmethanes, (H(3)M)(4-x)CHx ( M = Si, Ge; x = 0-3).