SYNTHESES, STRUCTURES, AND PROPERTIES OF COPPER(II) AND COPPER(I) COMPLEXES OF THE NEW BINUCLEATING LIGAND 1,3-BIS[BIS(2-PYRIDYLMETHYL)AMINO]BENZENE

The synthesis and characterization of the new copper complexes Cu2L'2(H2O)2(ClO4)4.2H2O (VI), Cu2L(H2O)2(ClO4)4.4H2O (VII), Cu2L(CH3CN)(PF6)2 (VIII), and Cu2L(CO)2(PF6)2 (IX) (L = 1,3-bis[bis(2-pyridylmethyl)amino]benzene, L' = 1-[bis(2-pyridylmethyl)amino]-3-[(2-pyridylmethyl)amino]benzene) are described. The crystal structures of the copper complexes were determined. Crystal data: complex VI, formula Cu2Cl4O20N10C48H54, triclinic space group P1BAR, Z = 1, a = 11.871 (4) angstrom, b = 12.313 (7) angstrom, c = 10.441 (14) angstrom, alpha = 108.45 (9)-degrees, beta = 102.98 (8)-degrees, gamma = 91.23 (4)-degrees; complex VII, formula Cu2Cl4O22N6C30H40, orthorhombic space group, Pmn2(1), Z = 2, a = 23.554 (3) angstrom, b = 8.998 (2) angstrom, c = 9.863 (2) angstrom. The copper(II) ions in VII are bridged by a perchlorate ion in the solid state. Complex VIII of formula Cu2P2F12N7C32H31 crystallizes in the triclinic space group P1BAR with Z = 2, a = 11.341 (2) angstrom, b = 17.421 (4) angstrom, c = 9.977 (2) angstrom, alpha = 93.98 (2)-degrees, beta = 106.89 (1)-degrees, and gamma = 91.47 (2)-degrees. The two copper(I) ions in VIII are in different environments because acetonitrile is bound to only one copper site. Complex IX of formula Cu2P2F12O2N6C32H28 crystallizes in the triclinic space group P1BAR with Z = 2, a = 13.465 (2) angstrom, b = 15.763 (2) angstrom, c = 9.9839 (9) angstrom, alpha = 94.07 (1)-degrees, beta = 101.46 (1)-degrees, and gamma = 113.41 (1)-degrees. The dicarbonyl complex IX is formed from the addition of two molecules of carbon monoxide to VIII. The binding constant for this reaction, measured at 22 +/- 2-degrees-C in dimethylformamide by cyclic voltammetry, is 2.1 x 10(8) M-2 per copper(I) dimer. Cyclic voltammetry and differential pulse voltammetry show that the redox potentials for Cu(II)Cu(II) --> Cu(I)Cu(II) --> Cu(I)Cu(I) are strongly solvent dependent. Reaction of the copper(I) complex with oxygen in methanol yields the same copper(II) species as is obtained independently from the reaction of Cu2+ with L. Hydroxylation of the benzene ring of the ligand is not observed.