PREPARATION OF AMINOBORANE AND LOW TEMPERATURE MASS SPECTROMETRIC STUDIES OF ITS REACTIVITY AND ENERGETICS.
GEORGIA INST OF TECH ATLANTA
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Aminoborane, H2BNH2, was synthesized by radio frequency discharge of borazine at 55 watts power level and -55C. The discharged borazine was quenched at -196C and aminoborane was separated from the unreacted borazine and other discharge products by vacuum distillation. Aminoborane was characterized by mass spectrometric techniques from -160C to -64C. The infrared spectrum of solid aminoborane was observed at liquid helium and liquid nitrogen temperatures. All spectra were identical, clearly resolving the N-H stretch at 3460 and 3367cm and the B-H band at 2525 and 2445cm. Aminoborane was observed to polymerize at about -155C yielding an inert white solid. No attempts to characterize the polymer were made. Attempts to react H2BNH2 with tetrafluoroethylene, 1, 3-butadiene, 2-3-dimethyl-1 3-butaciene, vinylmethylether, diazomethane and ozone were unsuccessful. Halogenated derivatives of aminoborane were obtained with BCl3 but not with BF3 or HCl. Dichloroaminoborane and possibly monochloroaminoborane, ClHBNH2, were observed mass spectrometrically as products of the BCl3 and H2BNH2 reaction. The bond dissociation energy H2B-NH2 was calculated to be 182 kcalmole using the measured appearance potentials of the fragmentations from aminoborane. Calculation of the heat of formation by two independent methods yielded values of -94 and -80 kcalmole at 25C. Author
- Inorganic Chemistry