Theoretical study of the N 2⋯CO + coupling system using density functional theory

Abstract

The doublet state cationic complexes formed by N 2(X 1Σ +) and CO +(X 2Σ +) have been studied using two density functional theory methods and two modest basis sets (6-311+G* and aug-cc-PVDZ). Five stable stationary points have been found on the global potential energy surface, which corresponds to five different coupling complexes, respectively. The accurate interaction energies are calculated to be 125.0 kJ mol −1 for the most stable tautomer and 61.28, 60.99, 60.74, 57.74 kJ mol −1 for other four tautomers through the basis set superposition error and zero-point vibrational energy correction. Computational results indicate that the N 2⋯CO + system has a large interaction energy 71.96 kJ mol −1 after consideration of the Boltzmann equilibrium distributions for all the available minima, which is in good agreement with the recent experimental findings.