Trimethylamine and 4-methylpyridine adducts of the mixed trihalides of boron: exchange reactions and nuclear magnetic resonance spectra

Abstract

Trimethylamine and 4-picoline adducts of the mixed boron trihalides have been identified in solution by ¹H and ¹⁹F n.m.r. spectroscopy. All 20 of the possible boron trihalide adducts of trimethylamine have been detected. Halogen exchange to give the mixed boron trihalide adducts occurs only when an excess of boron trihalide is present. In contrast to the free boron trihalides and oxygen-donor adducts of the boron trihalides, the slow halogen redistribution in the nitrogen-donor adducts allows isolation of individual mixed-halogen species.