Submaximal Interpenetration and Bicontinuous Three-Dimensional Channels in Porous Molecular Networks

Crystallization of tetrakis(3,5-dihydroxyphenyl)silane (1) from various solvents produces structures built from interpenetrated hydrogen-bonded diamondoid networks. Crystals grown from hexane/methyl propiolate show 5-fold interpenetration, with no volume remaining for the inclusion of guests. In contrast, crystals grown from mixtures of hexane with ethyl acrylate, ethyl acetate, THF, or dioxolane all exhibit submaximal 3-fold interpenetration. Approximately 50% of the volumes are accessible to guests, which occupy regions of diamondoid topology that replace missing networks of tetraresorcinol 1. Of particular interest are crystals containing THF or dioxolane, in which guests occupy two independent systems of interpenetrating diamondoid channels. The submaximally interpenetrated structures of tetraresorcinol 1 provide detailed models of complex topologies adopted by block copolymers and amphiphilic assemblies to optimize interfacial contact.