An ab initio study of the NCl bond

Closed-shell SCF MO calculations and geometry optimization were performed with the STO-3G, 3-21G and 6-31 G* basis sets for ten molecules containing the NCl group: ClNC, ClNO, ClNO 2 , ClNCO, ClNNN, Cl 3 N, Cl 2 NH, ClNH 2 , ClNCH 2 and ClNCH(NH 2 ). The hydrogenation energies were evaluated and qualitatively correlated with the RNCl bond angle and the Cl gross atomic population. For the molecules considered here, the NCl bond is rather weak and its stability - larger for longer than for shorter NCl distances - increases as the RNCl angle narrows. There appears to be no significant double-bond character for the shortest NCl bonds.