Boron–nitrogen polymers. I. Mechanistic studies of borazine pyrolyses

Abstract
Pyrolyses of B‐triamino‐N‐triphenyl‐, B‐triamino‐N‐trimethyl‐, and B‐trianilino‐borazines were performed between 150 and 300°C. Initial stages of degradation were accompanied by liberation of ammonia in addition to the expected aniline or methylamine; this was most pronounced for the methyl borazine. Aniline elimination proceeded more readily with the B‐anilino than the B‐amino isomer. Data obtained support a ring opening mechanism resulting in telomerizaton accompanied by aniline liberation and formation first of singly then doubly bridged dimers and finally doubly bridged tetramers. Thermal exposure up to 1000°C failed to give pure boron nitride; carbon was invariably retained.