Catena-Poly[[bis(quinoxaline-kappaN)cobalt(II)]-di-mu-dicyanamido-kappa2N1:N5) and catena-poly[[bis(quinoxaline-kappaN)copper(II)]-di-mu-dicyanamido-kappa2N1:N5

Abstract

Two new complexes, [Co(C 2 N 3 ) 2 (C 8 H 6 N 2 ) 2 ], (I), and [Cu(C 2 N 3 ) 2 (C 8 H 6 N 2 ) 2 ], (II), are reported. They are essentially isomorphous. Complex (I) displays distorted octahedral geometry, with the Co atom coordinated by four dicyanamide nitrile N atoms [Co-N = 2.098 (3) and 2.104 (3) A] in the basal plane, along with two monodentate quinoxaline N atoms [Co-N = 2.257 (2) A] in the apical positions. In complex (II), the Cu atom is surrounded by four dicyanamide nitrile N atoms [Cu-N = 2.003 (3) and 2.005 (3) A] in the equatorial plane and two monodentate quinoxaline N atoms [Cu-N = 2.479 (3) A] in the axial sites, to form a distorted tetragonal-bipyramidal geometry. The metal atoms reside on twofold axes of rotation. Neighbouring metal atoms are connected via double dicyanamide bridges to form one-dimensional infinite chains. Adjacent chains are then linked by π-π stacking interactions of the quinoxaline molecules, resulting in the formation of a three-dimensional structure.