O-H...O versus O-H...S hydrogen bonding I: Experimental and computational studies on the p-cresol x H2O and p-cresol x H2S complexes.

TLDR: Experimental data indicates that in the p-CR x H(2)S complex, the phenolic OH group acts as a hydrogen bond donor, and sulfur as the acceptor, and it indicates that thep-CRx H( 2)O complex was about half as strong as the p.CR x p-cresol complex, while the AIM and NBO analyses corroborate the experimental findings.

Abstract: The weak hydrogen bonding ability of sulfur-containing hydrides makes it difficult to study their complexes and has not been characterized experimentally so far. In this work, the hydrogen-bonded complexes of H2S and H2O with p-cresol (p-CR) were studied using a variety of techniques such as two-color resonant two-photon ionization (2c-R2PI) spectroscopy, single vibronic level fluorescence (SVLF) spectroscopy, resonance ion dip infrared spectroscopy (RIDIRS), and fluorescence dip infrared spectroscopy (FDIRS), with an aim of comparing the nature and strength of their respective hydrogen bonding abilities. The intermolecular stretch (σ) and the shift in the O−H stretching frequency of p-CR in the complex were taken as the measures of the O−H···O and O−H···S hydrogen bonding strength. The experiments were complemented by the ab initio calculations, atoms in molecules (AIM), natural bond orbital (NBO), and energy decomposition analyses carried out at different levels of theory. The experimental data indicate...