Amino-boranes and other Compounds containing B—N Bonds

Amino-boranes and other Compounds containing B—N Bonds.— Trimethyl-amine-borane, on exposure to Co y-rays at 77 K, forms the radical-anion McjN—BH3. This has a four-line e.s.r. spectrum, with a large hyperfine coupling to the boron atom. Annealing this species at temperatures 77 K gives Mc2N— BH,.  

Fluorescence spectra of 10 aminoborane analogues of stilbenes and styrenes were interpreted in terms of tt tt emission from a polar excited state to a less polar, more rigidly planar ground state. 

Amorphous poly(aminoborane)s are formed in high yield by reaction (15). 

They are not highly polymeric, n being mainly 3, 4, or 5, and they were much more highly reactive than cyclic borazanes. They were, therefore, thought to be 

LiNMe2 reacts with HB(NMc2)2, LiMc2N,BH3, and [Mc2NBH2]2 at decreasing rates to give B(NMe2)3 + LiH. Reactions (16) and (17) have been proposed to account for the behaviour of the last-named.  

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