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.
New Unexpected Coordination Modes of Azide and Picolinato Anions Acting as Bridging Ligands Between Copper(II) and Sodium or Potassium Ions. Synthesis, Crystal Structures and Spectral Characterizations of [MCu(picolinato)(N3)2]n (M = Na or K) Complexes
Abstract The polymeric complexes [NaCu(picolinato)(N3)2]n (1) and [KCu-(picolinato)(N3)2]n (2) have been synthesized and characterized by spectroscopic methods and X-ray crystallography. The overall spectral results indicate that the complexes contain different asymmetric azido ligands and axial five-coordinate copper(II) environments. In the structure of complex 1, each copper atom, which is chelated by 0(1) and N(1) of the picolinato anion, links N(11), N(21) and N(21a) of the azido groups [ Cu  O = 1.997(5) A and Cu  N = 1.957(6)–2.488(6) A ]. Each sodium atom is six-coordinated to oxygen atoms O(1), O(2c) and O(2d) [ Na  O = 2.299(6)–2.470(6) A ] picolinato ligand and nitrogen atoms N(11), N(11a), N(13e) [ Na  N = 2.454(7)–2.686(7) A ] of azide groups. Both μ(1,1) and μ(1,1,1,3) bridging azido ligands are linear and asymmetric [ N (11) N (12) = 1.204(8), N (12) N = 1.137(8), N (21) N (22) = 1.204(8), N (22) N (23) = 1.152(10 A ] . The structure of polymeric complex 2 features five-coordinate copper(II), eigth-coordinate potassium μ(1,3) and μ(1,1,1,3,3) bridging azido ligands and O,O,O′,O′,O′, N-hexadentate picolinato anions. The CuO bond length is 1.990(3) A, CuN distances from 1.903(3) to 2.649(4) A, whereas the KO distances are 2.729(3)–3.081(3) A and KN 2.845(4)–3.289(5) A.