Cooperation of Metal Ions and Hydrogen Bonded Anion-Water Units in the Self-Assembly of Supramolecular Architectures. G. William Orr, Leonard J. Barbour, Jerry L. Atwood, Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri, 65211

The pyridine-based exo-bidentate ligand 1 reacts with M(NO₃)₂, where M = Co, Ni, and Cu to give a new class of self-assembled molecular architectures (complex 2). A crystal structure of complex 2 reveals a dinuclear, macrotricyclic cation that forms a cage-like complex around four nitrate counterions. The nitrate ions are deeply embedded in the folds of the cationic structure where they form a hydrogen-bonded, cyclic array with four water molecules. The self-assembly of complex 2 shows a marked dependence on the nature of the anion.