Accession Number : AD0712371

Title :   STEREOCHEMISTRY OF REACTION AT GERMANIUM ATOMS.

Descriptive Note : Final scientific rept. 1 Apr 66-30 Jun 70,

Corporate Author : SUSSEX UNIV BRIGHTON (ENGLAND) CHEMICAL LAB

Personal Author(s) : Esborn,Colin ; Bassindale,Alan R. ; Jackson,Richard A. ; Turpin,Catherine L. ; Walsingham,Ruth

Report Date : JUL 1970

Pagination or Media Count : 40

Abstract : The first optically active compounds containing germanium or silicon bonded directly to platinum have bn successfully synthesised: (+)R3GeH + cis(PMe2Ph)2PtHCl yields R3GePt(PMe2Ph)2Cl and (-)Me-1-NpPhSiH + cis(PMe2Ph)2PtCl2 yields Me-1-NpPhSi(PMe2Ph)2Cl. Although the absolute configuration of the products remains to be determined, these compounds are of potential importance in the advancement of our understanding of the mechanism whereby transition metals catalyse the addition of germanium and silicon hydrides to unsaturated aliphatic compounds. Optically stable solutions of R3GeLi have been prepared from the hydride (-)R3GeH in hexane. The structure and reactivities of a number of silicon-containing radicals have been studied by e.s.r. spectroscopy. Tris(trimethylsilyl)methyl, obtained by abstraction of bromine from (Me3Si)4CBr, is a relatively stable free radical, though not so stable as Ph3C. (Me3Si) 3C.. has also been observed on photolysis of ((Me3Si)3C)2Hg. This is the first example of observation of an organic free radical produced by photolysis of an organomercurial. The quantum yields for decomposition of solutions of bis(trimethylsilyl) mercury in benzene or cyclohexane have been determined for light in the region of 4000A as 1.9 and 6.0 respectively. N.m.r. spectra of (Me3Si)2Hg in chlorobenzene showed that H-C-Si-199Hg satellites do not broaden appreciably over the range -16 to 104, indicating that trimethylsilyl groups are not exchanging rapidly between molecules even at 104 deg. (Author)

Descriptors :   (*GERMANIUM COMPOUNDS, *MOLECULAR ROTATION), (*SILANES, MOLECULAR ROTATION), (*METALORGANIC COMPOUNDS, MOLECULAR ROTATION), (*FREE RADICALS, SYNTHESIS(CHEMISTRY)), STEREOCHEMISTRY, MOLECULAR STRUCTURE, PLATINUM COMPOUNDS, CHLORIDES, ELECTRON PARAMAGNETIC RESONANCE, PHOTOLYSIS, MERCURY COMPOUNDS, NUCLEAR MAGNETIC RESONANCE, EXCHANGE REACTIONS, GREAT BRITAIN

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE