ON THE NATURE OF BORON-CARBON-NITROGEN COMPOUNDS SYNTHESIZED FROM ORGANIC PRECURSORS

Three compounds were prepared through pyrolysis of organic precursors. namely pyridine-borane, piperazine-borane, poly(acrylonitrile)-BCl3, following the routes proposed in the literature for the synthesis of s ingle-phase boron carbonitrides of various compositions. X-ray diffrac tion and MAS NMR studies performed on the powders obtained suggest tha t the resulting compounds are mixtures of amorphous boron and turbostr atically distorted hexagonal boron nitride and graphite rather than su bstitutional solid solutions of all three elements in a honeycomb netw ork, as was claimed previously. Such a conclusion is also consistent w ith the results of the XRD investigation of the samples after subseque nt heat treatment at 1800-2000 degrees C in argon and in nitrogen of a tmospheric pressure.