Quantum chemical study of the structure, spectroscopy and reactivity of NO+.(H2O)n=1-5 clusters

Linton, Kirsty A.; Wright, Timothy G.; Besley, Nicholas A.

Abstract

Quantum chemical methods including Møller-Plesset perturbation (MP2) theory and density functional theory (DFT) have been used to study the structure, spectroscopy and reactivity of NO+.(H2O)n=1−5 clusters. MP2/6-311++G** calculations are shown to describe the structure and spectroscopy of the clusters well. DFT calculations with exchange-correlation functionals with a low fraction of Hartree-Fock exchange give a binding energy of NO+.(H2O) that is too high and incorrectly predict the lowest energy structure of NO+.(H2O)2, and this error may be associated with a delocalisation of charge onto the water molecule directly binding to NO+. Ab initio molecular dynamics (AIMD) simulations were performed to study the NO+.(H2O)5 → H+.(H2O)4 + HONO reaction to investigate the formation of HONO from NO+.(H2O)5. Whether an intracluster reaction to form HONO is observed depends on the level of electronic structure theory used. Of note is that methods that accurately describe the relative energies of the product and reactant clusters did not show reactions on the time-scales studied. This suggests that in the upper atmosphere the reaction may occur owing to the energy present in the NO+.(H2O)5 complex following its formation.

Citation

Linton, K. A., Wright, T. G., & Besley, N. A. (2018). Quantum chemical study of the structure, spectroscopy and reactivity of NO+.(H2O)n=1-5 clusters. Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, 376(2115), Article 20170152

• Journal Article Type: Article
• Acceptance Date: Sep 11, 2017
• Online Publication Date: Feb 5, 2018
• Publication Date: Mar 13, 2018
• Deposit Date: Sep 19, 2017
• Publicly Available Date: Feb 5, 2018
• Journal: Philosophical Transactions A: Mathematical, Physical and Engineering Sciences
• Print ISSN: 1364-503X
• Electronic ISSN: 1471-2962
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 376
• Issue: 2115
• Article Number: 20170152
• Public URL: https://nottingham-repository.worktribe.com/output/881830
• Publisher URL: http://rsta.royalsocietypublishing.org/content/376/2115/20170152
• Contract Date: Sep 19, 2017