Theoretical investigation of the Ca +–N 2 and Ca 2+–N 2 complexes

Abstract

The structures, harmonic frequencies and binding energies for the ground states of Ca +–N 2 and Ca 2+–N 2 are computed at several theoretical levels, including Møller–Plesset second-order perturbation with full electron correlation and density functional theory. The charge–quadrupole interaction yields linear geometries as minima for both complexes, while the C 2v geometries are transition states. At the MP2 level, Ca +–N 2 has a dissociation energy ( D e) of 5.3 kcal/mol and a Ca +–N bond distance of 2.78 Å. Ca 2+–N 2 has a dissociation energy ( D e) of 23.8 kcal/mol and a shorter metal–ligand bond of 2.48 Å.