Mutual Interplay of Hydrogen–Hydrogen and Hydrogen–Halogen Interactions in NH 2 OH⋯HOX Complexes: A Quantum Chemical Study

ABSTRACT Hypohalous acids (HOX), as highly reactive atmospheric species, play a critical role in the catalytic cycles responsible for ozone layer depletion. In addition, these compounds possess strong oxidizing and antibacterial properties, which further highlight their significance; however, their intrinsic instability poses a major challenge for experimental investigations. Therefore, in this study, we employed quantum chemical calculations to evaluate the structural and electronic features of complexes formed between HOX and hydroxylamine (NH 2 OH, HA). Our results revealed the formation of four optimized cyclic complexes: two stabilized through dual hydrogen–hydrogen interactions (HB–HB, structures I and III), and two stabilized by combined hydrogen–halogen interactions (HB–XB, structures II and IV). Energy decomposition analysis (EDA) further demonstrated that the electrostatic contribution plays a dominant role in the stabilization of all complexes. The nature and characteristics of these complexes were systematically examined and evaluated using natural bond orbital (NBO), atoms‐in‐molecules (AIM), molecular electrostatic potential (MEP), EDA, and non‐covalent interaction (NCI) analyses.