Multicomponent Assembly of Macrocycles and Polymers by Coordination of Pyridyl Ligands to 1,4-Bis(benzodioxaborole)benzene
Multicomponent reactions between 1,4-benzenediboronic acid, catechol, and different pyridyl ligands are reported. The condensation of 1,4-benzenediboronic acid with catechol gives 1,4-bis(benzodioxaborole)benzene. Upon crystallization, the ester aggregates with the N-donor ligands through dative BN bonds. Depending on the nature of the pyridyl ligand, molecularly defined macrocycles or polymeric structures are obtained. 1D polymers are formed with 4,4-bipyridine and 1,2-di(4-pyridyl)ethylene, whereas a 2D network is obtained with the tetradentate ligand tetra(4-pyridylphenyl)ethylene. These results highlight the utility of dative BN bonds in structural supramolecular chemistry and crystal engineering.