The nitric oxide adsorption on gold neutral,cation, and anion atoms: A comparative ab initio MRCI—MRPT2 studies

The Au^ν + NO(²Π) → AuNO^ν reaction, for ν = ?1, 0, +1, anion, neutral, and cation are calculated and predicted at multireference configuration interaction (MRCI) and multireference second order perturbation (MRPT2) levels of theory, in this way the main parameters: reaction path surfaces, total and adsorption energies, optimized geometries, and Mulliken charges distribution are presented and compared. The AuNO (X ¹A′) complex is created spontaneously with ?11.32 and ?13.14 kcal/mol adsorption energies with the MRCI and MRPT2 approaches, respectively. The AuNO bonding in the neutral gold nitrosyl complex has a covalent character and the nitric oxide (NO) molecule is not dissociated. The others excited states (a ³A″, b ³A′, and A ¹A″) do not present bonding. The gold nitrosyl cationic (X ²A′, A ²A″, and a ⁴A″) and anionic (X ²A″ and a ⁴A″) are bonding and present a dative covalent bond. The Mulliken analysis done for ionic species show that the binding is done through soft electrostatic interactions, due to that there is some charge transfer, delocalized onto the NO molecule for the AuNO^± ionic species whereas the AuNO (X ¹A′) neutral complex presents a little charge transfer. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011