catena-Poly[[bis(quinoxaline-N)cobalt(II)]-di--dicyanamido-2N1:N5] and catena-poly[[bis(quinoxaline-N)copper(II)]-di--dicyanamido-2N1:N5]
Abstract:Two new complexes, [Co(C2N3)2(C8H6N2)2], (I), and [Cu(C2N3)2(C8H6N2)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) Å] in the basal plane, along with two monodentate quinoxaline N atoms [Co—N = 2.257 (2) Å] 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) Å] in the equatorial plane and two monodentate quinoxaline N atoms [Cu—N = 2.479 (3) Å] 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 – stacking interactions of the quinoxaline molecules, resulting in the formation of a three-dimensional structure.
Document Type: Research Article
Publication date: October 1, 2004