Accession Number : AD0723243

Title :   Carboranes from Alkylboron Hydrides.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA STATE COLL LOS ANGELES DEPT OF CHEMISTRY

Personal Author(s) : Groszek,Elliott ; Leach,John B. ; Wong,George T. F. ; Ungermann,Charles ; Onak,Thomas

Report Date : APR 1971

Pagination or Media Count : 33

Abstract : Both one-carbon and two-carbon carboranes have been prepared from the flow pyrolysis of several alkylboronhydrides. Carbahexaborane(7) and 2-carbahexaborane(9) have been prepared from methylpentaborane(9) and the corresponding C-methyl derivatives of these carboranes are obtained from ethylpentaborane(9). Pyrolysis of 1,2-dimethylpentaborane gives a modestly high yield of 1,5-C2B3H5 and, suprisingly, no detectable quantity of B-methyl derivatives of CB5H7. The four-carbon carborane C4B2H6 is obtained in low yield from 1,2-tetramethylenediborane(6). Temperature dependent nuclear magnetic resonance studies on CB5H7 and its C-methyl derivative reveal a bridge hydrogen tautomerism with a Free energy of ca. 14 and 12 kcal, respectively. (Author)

Descriptors :   (*BOROHYDRIDES, *PYROLYSIS), SYNTHESIS(CHEMISTRY), NUCLEAR MAGNETIC RESONANCE, MOLECULAR ISOMERISM, BORANES

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE