Synthesis and structures of heterocycle azidogallanes [(CH3)ClGaN3]4 and [(CH3)BrGaN3]3 en route to [(CH3)HGaN3]x:: An inorganic precursor to GaN

The synthesis of [(CH3)ClGaN3](4) (1) with a heterocyclic cyclooctane-like structure and [(CH3)BrGaN3](3) (2) with a trimeric structure has been demonstrated. X-ray structural determinations reveal that 1 and 2 consist of Ga4N4 eight-membered rings and Ga3N3 six-membered rings, respectively, in which the Ga atoms are bridged by the or nitrogens of the azide groups. [(CH3)ClGaN3](4) crystallizes in the tetragonal space group P (4) over bar 2(1)c with a = 11.017(4) Angstrom, c = 8.699(7) Angstrom, and Z = 8. [(CH3)BrGaN3](3) crystallizes in the triclinic space group P (1) over bar with a = 8.1080(10) Angstrom, b = 9.9390(13) Angstrom, c = 10.4439(13) Angstrom, alpha = 86.069(3)degrees, beta = 86.771(3)degrees, gamma = 80.829(2)degrees, and Z = 6. The reaction of 1 and 2 with LiGaH4 yields [(CH3)HGaN3](x), which is a new low-temperature source of GaN.