Crystalline Polymers Based on Dative Boron-Nitrogen Bonds and the Quest for Porosity

Crystalline networks based on dative boronnitrogen bonds were obtained by combining polytopic Ndonor ligands with polyboronic esters. The utilization of a tetrahedral boronate ester gave rise to a sheet structure, whereas either a linear polymer or a diamond-like network was observed for a tetrahedral N-donor ligand. The intrinsic flexibility of B <- N linkages favors tight intermolecular packing and interpenetration in the crystalline state. Amorphous B <- N networks, on the other hand, were found to possess porosity with BET surface areas of up to , similar to 300 m(2) g(-1). These materials display processability in organic solvents, and hydrolytic damage can be repaired by simple heating-cooling cycles.