Search results for "COPP"
showing 10 items of 3147 documents
High-dimensional mixed-valence copper cyanide complexes: Syntheses, structural characterizations and magnetism
2009
International audience; Reactions of CuCl 2 with different CN complexes in presence of a neutral ancillary ligand lead to two novel mixed-valence Cu complexes [Cu II (bpy)Cu I (CN) 3 ] n , 1 (bpy=2,2′-bipyridine) and {[Cu II (tn) 2 ][Cu I 4 (CN) 6 ]} n 2 (tn=1,3-diaminopropane). For compound 1, the asymmetric unit involves two Cu ions Cu1 and Cu2 (Cu I and Cu II centres, respectively) which strongly differ in their environments. The Cu1 ion presents a CuC 4 pseudo-tetrahedral geometry, while the Cu2 ion presents a CuN 5 slightly distorted square-pyramidal geometry. The extended structure of 1 is generated by three cyano ligands which differ in their coordination modes. One CN group has a μ …
Mono- and Binuclear Copper(II) and Nickel(II) Complexes with the 3,6-Bis(picolylamino)-1,2,4,5-Tetrazine Ligand
2021
Four new compounds of formulas [Cu(hfac)2(L)] (1), [Ni(hfac)2(L)] (2), [{Cu(hfac)2}2(µ-L)]·2CH3OH (3) and [{Ni(hfac)2}2(µ-L)]·2CH3CN (4) [Hhfac = hexafluoroacetylacetone and L = 3,6-bis(picolylamino)-1,2,4,5-tetrazine] have been prepared and their structures determined by X-ray diffraction on single crystals. Compounds 1 and 2 are isostructural mononuclear complexes where the metal ions [copper(II) (1) and nickel(II) (2)] are six-coordinated in distorted octahedral MN2O4 surroundings which are built by two bidentate hfac ligands plus another bidentate L molecule. This last ligand coordinates to the metal ions through the nitrogen atoms of the picolylamine fragment. Compounds 3 and 4 are cen…
DNA-binding of nickel(II), copper(II) and zinc(II) complexes: structure-affinity relationships
2013
Abstract Nickel(II), copper(II) and zinc(II) complexes with the same ligands normally display analogous coordination geometry and binding mode toward DNA. However, although qualitatively alike in structure and properties, different DNA-binding ability has often been observed. This review surveys the most recent examples of binding of the three metal ions complexed with monodentate and chelating bidentate to tetradentate ligands to DNA. An attempt has also been made to rationalize the observed trend in the values of the intrinsic DNA-binding constant, Kb, in terms of structural and chemical features.
Three one-dimensional systems with end-to-end dicyanamide bridges between copper(ii) centres: structural and magnetic properties
2002
The preparation, crystal structures and magnetic properties of three different copper(II) chains of formula [Cu(pyim)(H2O)(dca)]n(NO3)n (1), [Cu(dpa)(dca)2]n (2) and [Cu(bpa)(dca)2]n (3) [pyim = 2-(2-pyridyl)imidazole, dca = dicyanamide anion, dpa = 2,2′-dipyridylamine and bpa = 1,2-bis(4-pyridyl)ethane] are reported. A chain structure with single, symmetrical, end-to-end dca bridges is found in compound 1. This bridging mode, with two short, equatorially coordinated Cu–N bonds has not been previously observed in the [Cu(dca)Xn] (X = coligand) family of compounds. The copper atom in 1 has a distorted square pyramidal geometry with a bidentate pyim ligand and two nitrile nitrogen atoms from …
Syntheses, crystal structures and magnetic properties of copper(ii) dicyanamide complexes; dinuclear, chain and ladder compounds
2002
The preparation, crystal structures and magnetic properties of three heteroleptic copper(II) complexes with dicyanamide (dca) bridges, [Cu(bpca)(H2O)(dca)]2 (1) (bpca = bis(2-pyridylcarbonyl)amidate), [Cu(bpy)(dca)2]n (2) (bpy = 2,2′-bipyridine), [Cu2(bpm)(dca)4]n (3) (bpm = 2,2′-bipyrimidine) are reported. In addition, magnetic susceptibility measurements of the sheetlike polymer [Cu(phen)(dca)2] (4) (phen = 1,10-phenanthroline), structurally characterized previously, have been performed. In complex 1 pairs of mononuclear structural building blocks, [Cu(bpca)(dca)(H2O)], are loosely connected through a 1,3-dca bridge in which nitrile is equatorially bound and the amide is semi-coordinated …
Preparation, crystal structure and magnetic properties of di-2-pyridylamine (dpa) copper(II) complexes [Cu(dpa)(N3)2]n and [Cu2(dpa)2(NCO)4]
2008
Abstract The preparation, crystal structures and magnetic properties of two copper(II) complexes with di-2-pyridylamine (dpa) as end-cap ligand and azide (1) and cyanate (2) as bridging groups, [Cu(dpa)(N3)2]n (1) and [Cu2(dpa)2(NCO)4] (2), are reported. Compound 1 consists of uniform chains of copper(II) ions bridged by single μ-1,1-azido groups whereas that of compound 2 is made up of centrosymmetric dicopper(II) units with double μ-1,1-N-cyanate bridges, the other two cyanate groups acting as terminal ligands. The copper atoms in 1 and 2 are five-coordinated with two nitrogen atoms of a bidentate dpa ligand (1 and 2), one nitrogen atom from a terminally bound azide (1)/cyanate (2) and tw…
Mono-, di- and trinuclear 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tppz)-containing copper(II) complexes: syntheses, crystal structures and magnetic prop…
2004
Three new copper(ii) complexes of formula [Cu(tppz)(NCO)(2)].0.4H(2)O (1), [Cu(2)(tppz)Br(4)](2) and [Cu(3)(tppz)(C(5)O(5))(3)(H(2)O)(3)].7H(2)O (3)[tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine; C(5)O(5)(2-) = croconate, dianion of 4,5-dihydroxycyclopent-4-ene-1,2,3-trione] have been synthesised and structurally characterized by X-ray diffraction methods. The structure of complex is made up of neutral [Cu(tppz)(NCO)(2)] mononuclear units and uncoordinated water molecules. The mononuclear units are grouped by pairs to give a rather short copper-copper distance of 3.9244(4) angstroms. The structure of complex 1 consists of neutral tppz-bridged [Cu(2)(tppz)Br(4)] dinuclear units, the copper-copp…
Hydrogen and Halogen Bond Mediated Coordination Polymers of Chloro-Substituted Pyrazin-2-Amine Copper(I) Bromide Complexes
2020
A new class of six mono- (1
Copper(II) complexes with 2,5-bis(2-pyridyl)pyrazine and 1,1,3,3-tetracyano-2-ethoxypropenide anion: Syntheses, crystal structures and magnetic prope…
2009
International audience; The copper(II) complexes of formula [Cu2(2,5-dpp)(H2O)4(CF3SO3)4] · 2H2O (1) and [Cu2(2,5-dpp)(H2O)2(tcnoet)4]n (2) [2,5-dpp = 2,5-bis(2-pyridyl)pyrazine and tcnoet− = 1,1,3,3-tetracyano-2-ethoxypropenide anion] have been prepared and their structures determined by X-ray crystallographic methods. Compound 1 is a dinuclear complex where the 2,5-dpp molecule acts as a bis-bidentate bridge between the two copper centers, the electroneutrality being achieved by four terminally bound triflate anions. Each copper(II) ion presents an elongated octahedral CuN2O4 environment with two nitrogen atoms from 2,5-dpp and two water molecules in the basal plane and two triflate-oxyge…
Synthesis, X‐ray Crystal Structure and Magnetic Properties of Oxalato‐Bridged Copper( II ) Complexes with 2,3‐Bis(2‐pyridyl)pyrazine, 2,3‐Bis(2‐pyrid…
2004
Five oxalate-containing copper(II) complexes of formula [Cu(dpq)(H2O)(ox)]·5H2O (1), [Cu(dpp)(H2O)(ox)]·H2O (2), [Cu(bpz)(ox)]n (3), [Cu2(dpp)2(H2O)2(NO3)2(ox)]·4H2O (4) and [Cu2Cl2(bpz)2(H2O)2(ox)][Cu(bpz)(H2O)2(ox)]·2H2O (5) [dpq = 2,3-bis(2-pyridyl)quinoxaline; dpp = 2,3-bis(2-pyridyl)pyrazine; bpz = 2,2′-bipyrazine; ox = oxalate] were prepared and their structures were determined by X-ray diffraction on single crystals. Complexes 1 and 2 are discrete mononuclear complexes with oxalate and dpq (1)/dpp (2) acting as bidentate ligands. Complex 3 is a neutral oxalato-bridged (2,2′-bipyrazine)copper(II) chain where the oxalate adopts a bidentate/monodentate coordination mode, whereas 4 is an…