The effects of substitution on tetrakis(substituted imidazole)copper(II) trifluoromethanesulfonates.

The organic ligands 4-methyl-1H-imidazole and 2-ethyl-4-methyl-1H-imidazole react with Cu(CF(3)SO(3))(2).6H(2)O to give tetrakis(5-methyl-1H-imidazole-kappaN(3))copper(II) bis(trifluoromethanesulfonate), [Cu(C(4)H(6)N(2))(4)](CF(3)SO(3))(2), and aquatetrakis(2-ethyl-5-methyl-1H-imidazole-kappaN(3))copper(II) bis(tri fluoromethanesulfonate), [Cu(C(6)H(10)N(2))(4)(H(2)O)](CF(3)SO(3))(2). In the former, the Cu atom has an elongated octahedral coordination environment, with four imidazole rings in equatorial positions and two trifluoromethanesulfonate ions in axial positions. This conformation is similar to those in the analogous complexes tetrakis(imidazole)copper(II) trifluoromethanesulfonate and tetrakis(2-methyl-1H-imidazole)copper(II) trifluoromethanesulfonate. In the second of the title compounds, the ethyl groups block the central Cu atom, and a square-pyramidal coordination environment is formed around the Cu atom, with the substituted imidazole rings in the basal positions and a water molecule in the axial position.