Riley Schaeffer

INTERCONVERSION OF BORANES. II. DEUTERIUM ISOTOPE EFFECT IN THE DECOMPOSITION OF DIBORANE

The decomposition of B/sub 2/H/sub 6/ was shown to be five times faster than that of B/sub 2/D/sub 6/ by following the rate of hydrogen elimination. Factors affecting the concentration of one boron and three boron intermediates are discussed. The evidence is interpreted in terms of the reaction B/sub 3/H/ sub 9/ -B/sub 3/H/sub 7/ + H/sub 2/ as the rate controlling step of the decomposition. (auth)

Analysis of the NMR Spectrum of Tetraborane

The 11B NMR spectrum of B4H10 consists of a low‐field triplet exhibiting secondary triplet splitting and a high‐field doublet having extensive fine structure. A reinterpretation of this spectrum is proposed. The triplet structure arises from coupling of 11B in the BH2 groups to the two terminal protons and to the two adjacent bridge protons. The doublet can not be assigned from first‐order considerations. 11B–{1H} double resonance and 10B and 11B substitution studies indicate that the doublet fine structure arises from strong 11B–1H coupling interactions. The signs of JBH and JBBH are shown to be opposite from a comparison of the observed and calculated 11B spectra of tetraborane samples with various 10B/11B isotopic ratios. The proton spectrum of B4H10 consists of a quartet on which is superimposed a broad feature plus several smaller peaks. The spectra calculated for the 11BH2, 10BH2, and BH terminal protons and the bridge protons account for all the peaks in the 1H spectrum. A difference in the ease of...

Interconversion of boranes—IV a kinetic study of the decomposition of tetraborane-10☆

Abstract The kinetic study of the thermal decomposition of tetraborane-10 in the presence of carbon monoxide revealed that the reaction was approximately first order in tetraborane-10 and zero order in carbon monoxide. The heat of activation of the reaction was found to be 24,560 cal per mole. The close correspondence between the rate constants for this reaction and those previously determined for the conversion of tetraborane-10 to pentaborane-11 in the presence of diborane coupled with the fact that tetraborane-8 carbonyl is the major product of the reaction strongly suggests that tetraborane-8 is the intermediate in both reactions.

NON-METAL CHEMISTRY AT A CROSSROADS? A CASE HISTORY

Some comments are made concerning the needs of non-metal chemistry for development in the last quarter of the century.