Microporous Pillared Paddle-Wheel Frameworks Based on Mixed-Ligand Coordination of Zinc Ions

The reaction of Zn(NO₃)₂·6H₂O, various dicarboxylic acids, and either 4,4‘-bipyridine or N,N‘-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxydiimide produces a family of anisotropic, mixed-ligand, open-framework compounds featuring paddle-wheel-type coordination of Zn(II) pairs in two dimensions and pyridyl ligand pillaring in the third. Despite 2-fold interpenetration, the compounds contain channels of molecular dimensions and several are permanently microporous, displaying high internal surface areas.