Syntheses, structural analyses and redox kinetics of four-coordinate [CuL₂]²⁺ and five-coordinate [CuL₂(solvent)] ²⁺ complexes (L = 6,6′-dimethyl-2,2′-bipyridineor2,9- dimethyl-l,10-phenanthroline): Completely gated reduction reaction of [Cu(dmp)₂]²⁺ in nitromethanet

[Cu(2,9-dimethyl-1,10-phenanthroline)₂]²⁺ and [Cu(6,6′-bipyridine)₂]^2+/+ complexes with no coordinated solvent molecule were synthesized and crystal structures were analyzed. Electrochemical measurement were carried out by using a BAS 100B/W electrochemical analyzer. The coordination geometry around the Cu(I) center was in the D_2d symmetry while a D₂ structure was observed for the four-coordinate Cu(II) complexes. The study revealed that the D₂ structure of the Cu(I) complex retained in nitromethane, although a five-coordinate Thp species, was readily formed upon dissolution of the solid in acetonitrile.