Assembling Guests as Cyclic Tetramers in a Porous Hydrogen-Bonded Organic Framework

Arranging multiple guests in large-pore organic framework materials relies on a fundamental understanding of the framework-substrate and substrate-substrate interactions. In this work, we prepared a series of hydrogen-bonded organic framework complexes (HOF-1·guests) with aniline, o-toluidine, m-toluidine, p-toluidine, toluene, and N-vinyl-2-pyrrolidone. Single-crystal structural analyses revealed that these guests formed similar cyclic tetramers in HOF-1 due to the strong HOF-1-guest hydrogen bonding and N-H···πinteractions. Weak C-H···πor C-H···O interactions between guests were found to further stabilize these cyclic tetramers. The strong framework-substrate interaction enabled the uptake of aniline and N-vinyl-2-pyrrolidone in the same voids of HOF-1, and the residual acid in HOF-1 catalyzed an alkylation reaction within the voids.