Substituent Effects on the Structure and Supramolecular Assembly of Bis(dioxaborole)s Derived from 1,2,4,5-Tetrahydroxybenzene

The synthesis and structural characterization of bis(dioxaborole)s 13, based on 1,2,4,5-tetrahydroxybenzene, are described. The target compounds result from the facile dehydration reaction between the bis-diol and substituted phenyl boronic acids. While substituents on the terminal phenyl rings do not influence the planarity of the extended π-system through the boroles, they do significantly influence the intermolecular stacking arrangements for these compounds in the solid state. A combination of several weak and medium intermolecular interactions, including traditional π-stacking, CH−O hydrogen bonding, and a consistent phenyl−boron−phenyl sandwich motif determine the nature of the supramolecular assembly for these bis(dioxaborole)s.