Differential metathesis reactions of 2,2′-bipyridine and 1,10-phenanthroline complexes of cobalt(II) and nickel(II): cocrystallization of ionization isomers {[cis-Ni(phen)2(H2O)2][cis-Ni(phen)2(H2O)Cl]} (PF6)3⋅4.5H2O, and a synthetic route to asymmetric tris-substituted complexes |