Affiliation:
1. Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426 Ibrahimia, Alexandria 21321, Egypt
2. Institut für Physikalische und Theoretische Chemie, Technische Universität Graz, Rechbauerstraße 12, A-8010 Graz, Austria
Abstract
The structures of [Cu(pic)(NCS)(H2O)2] · 2H2O, complex 1, and
[Na2Co(pic)2(N3)2(H2O)6][Co(pic)2(N3)2] · 2H2O, complex 2, were determined by X-ray crystallography. Crystal data: 1, C7H12CuSN2O6, orthorhombic, space group Pbca, a = 8.749(4), b = 10.786(5), c = 26.882(9) Å, Z = 8, Rw =0.046 for 826 observed diffractometer data; 2, C24H32Co2Na2N16O16, triclinic, space group P1̄, a = 7.297(3), b = 8.806(4), c = 15.820(7) Å, a = 105.31(3), β = 95.09(3), γ = 99.86(3)°, Z = 1, and Rw = 0.064 for 1680 observed MoKa data.
Complex 1 features six-coordinated copper atoms, N,O-bidentate chelate picolinato anions, and μ(N,S) bridging thiocyanato groups with N at the basal site and S at the apical site of tetragonal bipyramid. The remaining two sites are occupied by aqua molecules, whereas two other water molecules serve as lattice water. The bridging thiocyanato groups link the copper polyhedra to form chains along the b axis of the unit cell. Complex 2 contains two Co(III) atoms located at different inversion centers. Co 1 in the [Na2Co(pic)2(N3)2(H2O)6]+ cation is six-coordinated by two trans picolinato anions (A) via their N 1 and O 1 atoms and by two terminal azido ligands. Two oxygen atoms (O 2 and O 2a) of two picolinate anions (A) act as μ(Ο,Ο) bridging atoms at basal sites to form a four-membered Na2O2 ring. Each sodium atom is further linked to three aqua ligands giving rise to trigonal-bipyramidal coordination environments. Two additional lattice water molecules are located between the dimeric sodium polyhedra. Co 2, in the [Co(pic)2(N3)2]- anion, is also six-coordinated by pairs of trans N,O-picolinate anions (B) and terminal azido groups.