Theoretical Studies on the NO∙∙∙H Interactions of Nitric Oxide, Organic Nitroxides, and Metal Nitrosyls in Selected Chemical Environments

Abstract

Nitric oxide (NO) and N‒O bond bearing species have garnered significant attention due to their fundamental importance in diverse fields such as biology, medicine, environmental science, and chemistry. These compounds exhibit intermolecular NO∙∙∙H hydrogen bonding interactions, which play a pivotal role in modulating various physicochemical properties, reaction pathways, kinetics, and many other practical applications. Our research aims to quantitatively analyze NO∙∙∙H interactions exhibited by NO, nitroxyl (HNO), nitrous acid (HONO), nitroxides, and metal nitrosyls in different chemical environments using various quantum chemically derived descriptors within the framework of electronic structure methods. We have conducted a comparative analysis of environmentally and biologically relevant NO∙∙∙H interactions within microhydrated networks of NO, HNO, and HONO, yielding valuable insights into the kinetics and mechanisms of water-mediated reactions involving these compounds. Additionally, we performed an extensive and quantitative theoretical assessment of NO∙∙∙H bonding in nitroxide radicals, potentially contributing to the development of stable nitroxides with improved properties. Furthermore, we have also investigated the activation of NO radicals through interaction with Brønsted acid site in metal-loaded zeolites (ZSM-5), with the obtained results potentially applicable to catalytic NO decomposition reactions catalyzed by metal-loaded zeolites.