B(N3)3 was isolated in a low-temperature argon matrix and its FTIR spectrum measured. The spectrum was consistent with the known gas-phase spectrum, and splitting due to the natural abundances of 10B and 11B was observed. Upon UV photolysis, new peaks at 2100, 1861, and 1803 cm-1 assigned to the linear molecule NNBN appeared as the B(N3)3 peaks decayed. Geometry optimizations and calculations of the ground-state frequencies for 10B and 11B isotopomers B(N3)3 [MP2/6-31G(d)] and NNBN [CCSD(T)/6-311G*] are reported, and the frequencies are compared to those observed in the IR spectra. The photolytic decomposition mechanism of B(N3)3 is discussed.

Al(N3)3 is produced by the stoichiometric reaction between Al(CH3)3 and excess HN3 at room temperature. The reaction is thought to proceed by the addition of HN3 to Al(CH3)3 followed by elimination of CH4, repeated three times to produce the fully azidified Al(N3)3. The product Al(N3)3 is nonvolatile and condenses as a film on the walls of the reaction vessel. The reaction products were observed in the gas phase and in low-temperature argon matrices by FTIR spectroscopy. Ab initio methods were used to compute the geometry and frequencies of Al(N3)3 , and the results are in good agreement with experimental data. The films produced upon condensation of Al(N3)3 contain the Al−N2 complex and AlN as well as the azide. Heating the films to 400 K removes the azide and the Al−N2, leaving AlN. This method may be useful as a low-temperature route to the synthesis of AlN thin films.

Gaseous HN3 reacts with surface-bound Ga(CH3)x species slowly at 300 K to produce thin films containing azide-substituted gallium compounds. When mixtures of HN3 and Ga(CH3)3 over the surface are irradiated at 253.7 nm, the reaction is dramatically accelerated, and films containing GaN and complexed N2 are produced. Heating of these films to 400 K drives off the N2 leaving GaN. The mechanism of the reaction is thought to involve photodissociation of HN3 to produce excited NH(a1Δ) and N2, followed by insertion of the NH(a1Δ) into the Ga–C bond of surface-bound Ga(CH3)x molecules. The insertion product eliminates CH4 to leave GaN.

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Synthesis of Al(N3)3 and the Deposition of AlN Thin Films.-Synthesis of Al(N3)3 is performed by reaction of AlMe3 vapor with excess HN3 gas at room temperature. Due to the existence of AlMe3 as dimer at 298 K, the reaction is quite slow at this temperature. Al(N3) 3, which is nonvolatile at 298 K, condenses as film on the reactor walls. During film formation some of the azide decomposes to Al-N2 complexes and AlN. By gentle heating the azide and the Al-N2 are removed, leaving amorphous AlN. This behavior suggests the generation of AlN thin films from the continuous flow of 3 : 1 AlMe3-HN3 mixtures over a substrate heated at 400 K. -(LINNEN, C. J.; MACKS, D. E.; COOMBE, R. D.; J.