STRUCTURAL-PROPERTIES OF [(TRICHLOROSILYL)AMINO]DICHLOROBORANE

Density functional calculations have been performed on [(trichlorosily l)amino]dichloroborane (TADB, Cl3SiNHBCl2), a molecular precursor of t he recently synthesized ceramic Si3B3N7. An infrared spectrum of the s ubstance was determined both experimentally using a Fourier transform infrared spectrometer and by means of quantum chemical. calculations. The computed infrared spectrum is in good agreement with experiment an d allows the assignment of the more intense peaks to the various vibra tional modes. Electronic structure calculations show that the nitrogen atom in TADB is not pyramidally coordinated; the molecule rather cont ains a planar Si-NH-BCl2 unit with a partial N-B double bond.