Halogen and Hydrogen Bonding Benzothiophene Diol Derivatives: A Study Using ab initio Calculations and X-Ray Crystal Structure Measurements

The aim of this study is to describe and compare the supramolecular interactions, in the solid state, of chloro-, bromo-, and iodobenzothiophene diols. The compounds were obtained through organo-catalyzed reactions starting from 3-substituted halobenzothiophene carbaldehydes. Energies of the noncovalent interactions were obtained by density functional theory calculations. Bond distances and angles were found to be in accordance with those determined by X-ray structure analysis. anti-Bromobenzothiophene derivatives showed strong halogen ···p interactions between bromine and the heterocyclic phenyl ring, corresponding to an energy of 7.5 kcalmol1. syn- Bromo and syn-iodo derivatives appeared to be isostructural, showing X···O (carbonyl) interactions, p stacking, and formation of extended hydrogen bonding networks. In contrast, the chloro derivatives displayed no halogen bonding interactions