An analysis of the hydrogen bond in BASE-HF complexes using the theory of atoms in molecules

TLDR

A hydrogen bond arises from the interaction of two closed‑shell systems, quantified by the mutual penetration of their van der Waals envelopes. The study examines the nature, energetics, and mechanism of BASE‑HF hydrogen bonds using the theory of atoms in molecules. RHF/6‑311++G**//6‑31G** calculations were used to quantify electron redistribution and changes in atomic properties upon hydrogen bond formation, providing a qualitative understanding of the interaction. The study finds that the extent of van der Waals envelope penetration and its governing factors are crucial for determining hydrogen bond strength.

Abstract

The nature, energetics and mechanism of BASE-HF hydrogen bonding (where BASE = OC, SC, N2, HCN, H3N, O3, SCO, CO2, N2O, SO2, H2CO, H2O, HF, H3P, H2S and HCl) are examined using the theory of atoms in molecules. The results are obtained from RHF/6-311 + +G**//6-31 G** calculations. A quantitative description of the electron redistribution and changes in atomic properties, including populations, energies, volumes and moments upon hydrogen bond formation are given by the theory, information which in turn provides a qualitative understanding of the hydrogen bond. A hydrogen bond results from the interaction of two closed-shell systems and the theory quantifies the concept of the mutual penetration of the van der Waals envelopes of the acid and base molecules. It is found that the extent of this penetration and the factors which govern it are of paramount importance in determining the strength of the interaction.