Solution and Solid-State Variation of Cupric Phenanthroline Complexes

The 1:1 cupric-phenanthroline complexes, [Cu(5,6-Me2-phen)(MeCN)2(BF4)](BF4) (1), [Cu(o-phen)(MeCN)2(H2O)](BF4)2 (2), and [Cu(5-Cl-phen)(MeCN)2(BF4)](BF4) (3), have been prepared and characterized by X-ray crystallography.
The structures of 1 and 3 are characterized by an equatorial plane about the copper center consisting of a
phenanthroline ligand and two acetonitrile ligands. The copper units are connected by bridging counterions in the
axial positions of the pseudo-octahedral metal centers to form one-dimensional solid-state linkages. The structure
of 2 contains the same equatorial plane as 1 and 3, but an axial water ligand completes a square pyramidal
geometry for each discrete metal unit. Although the solid-state structures vary for the three complexes, characterization
through electronic spectroscopy and cyclic voltammetry reveals similar behavior for all three complexes in solution.