Molecular clusters of arenesulfonyl halides and water: a PM3 quantum-chemical calculation

The PM3 semiempirical method was applied to calculate structures and intera ction energies for clusters between benzenesulfonyl chloride and water mole cules (up to 20) and of a series of para-substituted benzenesulfonyl chlori des (4-OCH3, 4-CH3, 4-NH2, 4-F, 4-Cl, 4-Br, 4-CN, and 4-NO2) and 1 water mo lecule. The energies of hydrogen bonds between water molecules and the oxyg en and chlorine atoms of the sulfonyl chloride group, and also between wate r molecules and hydrogen atoms of the benzene ring were estimated. Successi ve addition of water molecules to the hydration shell of benzenesulfonyl ch loride results in strengthening of the system of hydrogen bonds around the latter, lengthening of the S-Cl bond and its increasing polarization, short ening of the C-S bond, and decrease in the energy of the LUMO. The interact ion energies between water molecules and the functional groups of the para substituents are not uniquely determined by the atomic charges in the subst ituents and increase in the series 4-OCH3, 4-CN, Ph, 4-CH3, 4-Br,4-Cl, 4-NH 2, 4-F, 4-NO2.