The HNO⁻ radical anion: A proposed intermediate in diazeniumdiolate synthesis using nitric oxide and alkoxides

Abstract

The strategy of synthesizing diazeniumdiolates (X-N(O)=NO) through the coexistence of nitric oxide and alkoxides (RO) was introduced by Wilhelm Traube 120 years ago. Today, despite the wide use of diazeniumdiolate derivatives to release nitric oxide in the treatment of cancer, the first step of the reaction mechanism for diazeniumdiolate synthesis remains a mystery and is thought to be complex. We have studied the gas-phase reactions of nitric oxide with alkoxides at room temperature. An electron-coupled hydrogen transfer is observed, and the radical anion HNO is the only ionic product in these reactions. HNO can further react with nitric oxide to form NO and HO.

Weak Interactions in Interstellar Chemistry: How Do Open Shell Molecules Interact with Closed Shell Molecules?

“…Vis-à-vis terrestrial chemistry, what the ISM lacks in terms of the size of the molecules is more than compensated by the wide prevalence of both open shell and closed shell molecules in the ISM. Thus, some very rich open shell chemistry often considered to be exotic in terrestrial chemistry is a regular feature in the ISM routinely studied using mass spectrometric, spectroscopic, and computational techniques. − …”