Density functional theory study on (F2AlN3)n (n = 1–4) clusters

Possible geometrical structures and relative stabilities of (F2AlN3)n (n = 1–4) clusters were studied using density functional theory at the B3LYP/6-311+G* level. The optimized clusters (F2AlN3)n (n = 2–4) possess cyclic structure containing Al–Nα–Al linkages, and azido in azides has linear structure. The IR spectra of the optimized (F2AlN3)n (n = 1–4) clusters have three vibrational sections, the whole strongest vibrational peaks lie in 2218–2246 cm−1, and the vibrational modes are N3 asymmetric stretching vibrations. Trends in thermodynamic properties with temperature and oligomerization degree n are discussed, respectively. A study of their thermodynamic properties suggests that monomer 1A forms the most stable clusters (2A, 3A, and 4B) can occur spontaneously in the gas phase at temperatures up to 800 K.