Microporous pillared paddle-wheel frameworks based on mixed-ligand coordination of zinc ions.

The reaction of Zn(NO3)2 x 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.