On the Aromaticity in Cyclic H‐Bonded Chains: Linking HOMIA Descriptor to Molecular Properties

ABSTRACT Aromaticity is a central concept in organic chemistry to explain the high stability of conjugated rings. This study extends this concept to cyclic hydrogen‐bonded (H‐bonded) chains by introducing a modified descriptor, the harmonic oscillator model of intermolecular aromaticity (HOMIA), to quantify aromaticity in cyclic H‐bonded chains of HCN, HNC, and HF. Using density functional theory (DFT) with dispersion corrections, we investigate quantitative correlations between HOMIA and various molecular properties, including structural, energetic, vibrational, and magnetic parameters. Notably, the aromatic character is related to the cooperative effects. Our results suggest that the HOMIA index captures trends in H‐bond lengths, cooperative energies, and NMR shielding. Intermolecular aromaticity is intrinsically related to H‐bond cooperativity: it enhances electron delocalization and charge transfer in shorter chains, while in longer chains conventional chain‐length cooperative effects dominate. These findings provide a novel framework for characterizing intermolecular aromaticity, extending the applicability of the concept of aromaticity to non‐covalently bonded systems.