Journal of Chemical Physics vol:114 issue:18 pages:7911-7917
Ab initio molecular orbital calculations up to the coupled-cluster level with the aug-cc-pVQZ basis set allowed us to have a new look at the electron affinity of nitrous oxide (N2O) resulting in a detection of a new N2O- entity, and thereby a novel mechanism for the dissociative electron attachment process, N2O+e(-)-->N-2+O-. Addition of an electron to the linear N2O ground state (X (1)Sigma (+)) leads first to an open-chain bound anion which lies 25 kJ/mol above the neutral. Upon a cyclization of the open anion with an additional energy barrier of 25 kJ/mol, a cyclic anionic species is formed which is more stable than the open isomer and lies now, at most, 3 kJ/mol above the neutral ground state (the transition structure for cyclization being 50 kJ/mol above neutral N2O). The cyclic anionic species constitutes a weak complex between N-2 and O- characterized by a binding energy of only 16 kJ/mol. The electronic structure of the anion complex is analyzed, a number of earlier experimental results are clarified and a resolution for the long-standing disagreement between experiment and theory around the electron affinity of N2O is proposed. (C) 2001 American Institute of Physics.