Copper(II) diclofenac complexes: Synthesis, structural studies and interaction with albumins and calf-thymus DNA.

The reaction of the copper(II) diclofenac complex [Cu(dicl)2(H2O)2] (1) (dicl = deprotonated diclofenac (Hdicl)) with the chelating N-donor ligands ethylenediamine (en), propan-1,3-diamine (pn), unsymmetrical dimethylethylene-diamine (unsym-dmen) and N,N,N',N'-tetramethylethylene-diamine (temed) in methanol-water (4:1 v/v) yielded the novel copper(II) complexes [Cu(en)2(H2O)2](dicl)2·2H2O (2), [Cu(pn)2(H2O)2](dicl)2·2H2O (3), [Cu(unsym-dmen)2(H2O)](dicl)2·H2O (4) and [Cu(temed)(dicl)2] (5), respectively. All the synthesized complexes were characterized by spectroscopic (UV-vis, FT-IR) methods. The structures of complexes 2, 3 and 5 were unambiguously determined by single-crystal X-ray crystallography. X-ray structures of complexes clearly revealed the ionic structure of complexes 2, 3 and the covalent structure of complex 5. The geometry of complex 4 was optimized by Density Functional Theory (DFT) calculations. The ability of the complexes 1-5 to bind to calf-thymus DNA was monitored in vitro by diverse techniques (UV-vis spectroscopy, cyclic voltammetry, viscosity measurements) and via competitive studies with ethidium bromide. The interaction of complexes 1-5 with bovine serum albumin was studied in vitro by fluorescence emission spectroscopy and the corresponding binding constants were calculated. The biological behavior of complexes 1-5 was compared with previously reported Cu(II), Mn(II) and Ni(II) complexes of diclofenac.

Metal-Metal Interactions in Trinuclear Copper(II) Complexes [Cu3(RCOO)4(H2TEA)2] and Binuclear [Cu2(RCOO)2(H2TEA)2]. Syntheses and Combined Structural, Magnetic, High-Field Electron Paramagnetic Resonance, and Theoretical Studies.

The trinuclear [Cu3(RCOO)4(H2TEA)2] copper(II) complexes, where RCOO(-) = 2-furoate (1), 2-methoxybenzoate (2), and 3-methoxybenzoate (3, 4), as well as dimeric species [Cu2(H2TEA)2(RCOO)2]·2H2O, have been prepared by adding triethanolamine (H3TEA) at ambient conditions to hydrated Cu(RCOO)2 salts. The newly synthesized complexes have been characterized by elemental analyses, spectroscopic techniques (IR and UV-visible), magnetic susceptibility, single crystal X-ray structure determination and theoretical calculations, using a Difference Dedicated Configuration Interaction approach for the evaluation of magnetic coupling constants. In 1 and 2, the central copper atom lies on an inversion center, while in the polymorphs 3 and 4, the three metal centers are crystallographically independent. The zero-field splitting parameters of the trimeric compounds, D and E, were derived from high-field, high-frequency electron paramagnetic resonance spectra at temperatures ranging from 3 to 290 K and were used for the interpretation of the magnetic data. It was found that the dominant interaction between the terminal and central Cu sites J12 is ferromagnetic in nature in all complexes, even though differences have been found between the symmetrical or quasi-symmetrical complexes 1-3 and non-symmetrical complex 4, while the interaction between the terminal centers, J23, is negligible.

Stabilization of tetrameric metavanadate ion by tris(1,10-phenanthroline)cobalt(III): Synthesis, spectroscopic and X-ray structural study of [Co(phen)(3)](3)(V(4)O(12))(2)Cl·27H(2)O.

A new complex salt of composition [Co(phen)(3)](3)(V(4)O(12))(2)Cl·27H(2)O (phen = 1,10-phenanthroline and [V(4)O(12)](4-) = tetrameric dodecaoxotetravanadate ion) was synthesized by reacting appropriate salts in aqueous medium. The complex salt has been characterized by elemental analyses, thermogravimetric analysis (TGA), cyclic voltammetry (CV), FT-IR and UV/Vis spectroscopies, solubility product and conductance measurements. Single crystal X-ray structure determination revealed ionic structure consisting of three complex cations, [Co(phen)(3)](3+), two [V(4)O(12)](4-) anions, one chloride and twenty seven lattice waters. Detailed structural and spectroscopic analyses of [Co(phen)(3)](3)(V(4)O(12))(2)Cl·27H(2)O show that the large anion is stabilized by the large cationic metal complex as there is preferred shape compatibility that leads to a large number of lattice stabilizing non-covalent interactions.

Syntheses and characterizations of three low-dimensional chloride-rich zincophosphates assembled about [d-Co(en)(3)](3+) and [dl-Co(en)(3)](3+) complex cations.

Three new chloride-rich zincophosphates including two zero-dimensional (0D) clusters [dl-Co(en)3]2[Zn4(H2PO4)2(HPO4)2Cl8] (denoted ZnPO-CJ33) and [d-Co(en)3]2[Zn4(H2PO4)2(HPO4)2Cl8] (denoted ZnPO-CJ34), and one-dimensional (1D) zincophosphate chain [dl-Co(en)3][Zn2(H2PO4)(HPO4)2Cl2] (denoted ZnPO-CJ35) have been solvothermally prepared. ZnPO-CJ33 and ZnPO-CJ34 possess the same cluster structure as the macroanionic [Zn4H6P4O16Cl8]6- unit formed by alternation of ZnOCl3/ZnO3Cl and HPO4/H2PO4 tetrahedra but differ in the countercations. The racemic [dl-Co(en)3]3+ cations are located among the clusters of ZnPO-CJ33, whereas chiral [d-Co(en)3]3+ cations are located among the clusters of ZnPO-CJ34. ZnPO-CJ34 templated by the optically pure chiral [d-Co(en)3]3+ cations is the first chiral monomeric zincophosphate. ZnPO-CJ35 templated by the racemic [dl-Co(en)3]3+ cations possesses a 1D infinite chain structure formed by the alternation of ZnO3Cl and HPO4/H2PO4 tetrahedra. The 1D chain structure of ZnPO-CJ35 can also be viewed as generated from the condensation of 0D clusters of ZnPO-CJ33, with the terminal Cl ions replaced by HPO4 groups. Experimentally, the structural transformation from ZnPO-CJ33 to ZnPO-CJ35 has been investigated.

The first X-ray structure of a hexaamminecobalt(III) salt with two different complex chlorocadmium anions: synthesis, characterization and crystal structure of [Co(NH3)6]4[CdCl6][CdCl4(SCN)(H2O)]2Cl2.2H2O.

In the title complex salt, tetrakis[hexaamminecobalt(III)] hexachlorocadmate(II) bis[aquatetrachlorothiocyanatocadmate(II)] dichloride dihydrate, the discrete ions, i.e. [Co(NH3)6]3+, Cl-, [CdCl6]4- (located on an inversion centre) and [CdCl4(SCN)(H2O)]3-, together with cocrystallized water molecules, are assembled by means of a network of hydrogen-bonding interactions. This is the first X-ray structure determination of a hexaamminecobalt(III) salt with two different complex chlorocadmium anions.

Second-sphere coordination in anion binding: sodium hexaamminecobalt(III) tetrakis(4-fluorobenzoate) monohydrate.

In sodium hexaamminecobalt(III) tetrakis(4-fluorobenzoate) monohydrate, Na[Co(NH3)6](C7H4FO2)4.H2O, determined at 180 K, [Co(NH3)6]3+ cations lie on centres of inversion and form layers in which their C4 axes lie perpendicular to the layer planes. 4-Fluorobenzoate anions lie on twofold axes and general positions and adopt near-planar geometries. Na+ cations and water molecules lie on twofold axes, forming [NaO5] square pyramids that lie between the [Co(NH3)6]3+ cations. The second-sphere interactions between [Co(NH3)6]3+ cations and 4-fluorobenzoate anions comprise edge-to-face and vertex-to-face arrangements. The structure is closely comparable with that of the benzoic acid salt, demonstrating that fluorination of the anion in the para position has no significant influence on the second-sphere interactions and minimal influence on the gross crystal structure.

Second-sphere coordination in anion binding: cis-diazidobis(ethylenediamine-kappa(2)N,N')cobalt(III) picrate.

In the title compound, [Co(N3)2(C2H8N2)2](C6H2N3O7), the cations share NH2...NH2 edges with picrate anions via second-sphere N-H...O hydrogen bonds.