Synthesis and characterization of poly-(aminoborane) as a new boron nitride precursor

During the solution reaction of NaBH4/(NH4)(2)SO4 in tetraglyme to form bor azine, polymeric aminoborane (NH2BH2)(x) has beer isolated as a white powde r The powder was characterized fry thermal gravimetric analysis/differentia l scanning calorimetry, infrared and mass spectroscopies, and powder X-ray diffraction. Solid-state N-15 and B-12 nuclear magnetic resonance firmly pr oved that the chain-like poly(aminoborane) evolved a partially condensed B3 N3 ring structure by dehydrogenative condensation between chains at 200 deg rees C. Pyrolysis of the polymer in a nitrogen stream up to 1400 degrees C led to a 75% yield of hexagonal boron nitride with an interlayer spacing of 3.37 A. Copyright (C) 1999 John Wiley & Sons, Ltd.