A new packing variant of catena-poly[[aquachlorocopper(II)]-mu-pyrazine-2-carboxylato-O,N:N'].
Single crystals of the title coordination polymer, [CuCl(C5H3N2O2)(H2O)], have been prepared by hydrothermal synthesis. The compound is composed of infinite one-dimensional chains of pseudo-square-pyramidal Cu(II) ions connected via pyrazine-2-carboxylate ligands. A network of O-H...O hydrogen bonding between adjacent chains is responsible for a bilayer structure different from the previously reported polymorph.
1D polymeric copper(II) complexes containing bridging tridentate pyrazinato and terminal chloro or azido anions. Synthesis, spectral, structural and thermal study of [CuCl(pyrazinato)(H2O)]n and [Cu(N3)(pyrazinato)(H2O)]n complexes
Abstract The polymeric complexes [CuCl(pyrazinato)(H2O)]n (1) and [Cu(N3)(pyrazinato)(H2O)]n (2) have been synthesized and characterized by spectroscopic methods and X-ray crystallography. The overall spectral results indicate that these complexes contain tridentate pyrazinato ligands, terminal chloride or azide groups and aqua molecules. In the structure of complex (1), each copper atom, which is chelated by O(1) and N(1) atoms of the pyrazinato anions, links Cl(1) atom, O(3) atom from an aqua molecule and the second nitrogen, N(2) from a pyrazinato group of a neighbouring unit giving rise to a 1D polymeric structure. The structure of complex (2), which is very similar to 1 features five coordinate copper(II) atom, N, N,O-tridentate pyrazinato ligand, terminal azido ligand, aqua molecule and 1D polymeric structure. There are different types of hydrogen bonds in both complexes. The thermal decomposition of complexes (1) and (2) was investigated thermogravimetrically in nitrogen atmosphere.
Polymeric complexes of cadmium(II) bridged simultaneously by tetradentate picolinato and μ(1,1)-azido or μ(N,S)-thiocyanato anions. Synthesis and structural characterization of [Cd(picolinato)(N3)]n and [Cd(picolinato)(NCS)]n
Two mixed ligand complexes of picolinic acid and cadmium(I I) azide or thiocyanate, namely catena-μ(1,1)-azido-μ(N,O,O,O′-picolinato)cadmium(II) (1) and catena μ(N,S)-thiocyanato-μ(N,O,O,O'−picolinato)cadmium(II) (2) have been prepared and characterized by spectroscopic and X-ray crystallographic methods. The coordination environment of the cadmium(II) atom in complex 1 is a distorted octahedron. Each metal atom is chelated by a picolinato anion via its ring nitrogen N(1) [Cd-N = 2.356(6) A] and a carboxylate oxygen atom O(1). O(1) is further coordinated to another cadmium atom to form cyclic Cd2O2 units [Cd-O = 2.327(5) and 2.459(5) A]. 0(2) links a third metal centre. The cyclic Cd2O2 units are connected by μ(1,1) bridging azido groups to form sheets of polyhedra which are arranged normal to the long c-axis of the unit cell. Complex 2 features distorted octahedral cadmium atoms, N,O,O,O′-tetradentate chelating bridging picolinato anions, μ(N,S) bridging thiocyanato ligands and one-dimensional chains of polyhedra which are oriented along the b-axis of the monoclinic unit cell. The IR and Raman spectra are also reported and correlated with the structures of the complexes. The vibrational bands of diagnostic value are compared to the values of the free acid.