Search results for "COPP"

Strong protective action of Copper(II) N-substituted sulfonamide complexes against reactive oxygen species.

2004

Copper(II) complexes of N -benzothiazolsulfonamides, [Cu( N -2-(5,6-dimethylbenzothiazole)toluenesulfonamidate) 2 (dmso) 2 ] ( 1 ), [Cu( N -2-(6-chlorobenzothiazole)benzenesulfonamidate) 2 (dmso) 2 ] ( 2 ) and [Cu( N -2-(6-chlorobenzothiazole)toluenesulfonamidate) 2 (dmso) 2 ] ( 3 ) with interesting protective properties against superoxide radicals have been prepared. The compounds have been characterized by X-ray diffraction and their chemical properties have been studied by spectroscopic methods. The crystal structure of 1 shows that the copper(II) is surrounded by two benzothiazole N atoms from the sulfonamide ligands and two O atoms from the dimethylsulfoxide molecules in a square plana…

Mono- and Di-chloro-bridged Discrete Dimers and Trimers and Mono-Chloro-Bridged 1D-Coordination Polymer of Copper(II). Magneto-structural Studies

2014

The synthesis, structural characterization, and magnetic properties of three copper(II) complexes, a mono-chloro-bridged [Cu2II(L6)2(μ-Cl)(Cl)(CuIICl4)] (1) and a dichloro-bridged [CuII2(L7)2(μ-Cl)2][ClO4]2 (3) discrete trimers and dimers, and a mono-chloro-bridged 1D-coordination polymer [CuII(L6)(μ-Cl)][ClO4]·CH3CN (2), are reported. Molecular structures were authenticated by X-ray crystallography. Temperature-dependent magnetic measurements carried out on powdered samples of 1–3 indicated a very weak antiferromagnetic exchange-coupling within the {CuII(μ-Cl)CuII(μ-Cl)CuIICl3}+ units in 1 [Curie-Weiss plot: θ = –0.19(1) K and g = 2.07(1)], a ferromagnetic behavior within {CuII(μ-Cl)2CuII}…

Novel cuprous oxide morphologies using amino acids and carboxylic acids as structure directing agents in a simple hydrothermal method

2021

Abstract The reactivity and catalytic performance of cuprous oxide (Cu2O) particles rely on the size and morphology of the Cu2O crystals. In this study, a facile and mild hydrothermal route is applied to generate novel uniform cuprous oxide microcrystals, using non-toxic and low-cost carboxylic acids (O,O-type) and amino acids (N,O-type) as structure directing agents. N,O-type complexing agents showed a higher ability to reduce the copper species compared to the O,O-type ligands. Using oxalate and citrate complexes, pure Cu2O was obtained after 4 h at 200 °C, whereas the oxalate-based complex leads to the morphology of uniformly stepped microcubes, the citrate complex as precursor leads to …

2020

Heteroleptic [Cu(P^P)(N^N)][PF6] complexes, where N^N is 5,5′-dimethyl-2,2′-bipyridine (5,5′-Me2bpy), 4,5,6-trimethyl-2,2′-bipyridine (4,5,6-Me3bpy), 6-(tert-butyl)-2,2′-bipyridine (6-tBubpy) and 2-ethyl-1,10-phenanthroline (2-Etphen) and P^P is either bis(2-(diphenylphosphino)phenyl)ether (POP, PIN [oxydi(2,1-phenylene)]bis(diphenylphosphane)) or 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos, PIN (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane)) have been synthesized and their NMR spectroscopic, mass spectrometric, structural, electrochemical and photophysical properties were investigated. The single-crystal structures of [Cu(POP)(5,5′-Me2bpy)][PF6], [Cu(xantphos)(5,5′…

Photosensitive properties of composite films based on copper chloride in polymer matrix

2013

The composite films based on PMMA and CuCl2 were prepared. Transmission spectra of the films before and after illumination by different laser lines (405, 448, 456 nm) were measured. The reversible character of the composite photosensitivity was fixed. The phenomenon of direct surface relief formation after laser beam illumination of composite films was described. The holographic gratings were recorded by different exposure (200 – 500 J/cm2) in the films with different concentration (8 and 20 wt. %) of copper salt. The film sensitivity dependence on polymer molecular weight was studied. Surface relief of the gratings was measured by AFM.

Assembling Magnetic Blocks: A Strategy to Control the Nuclearity and Magnetic Properties of Polynuclear Complexes

1996

Synthetic strategies dealing with the polymerization of either di-μ-hydroxocopper(II) complexes or 2,2′-bipyrimidine (bpym)-containing first row transition metal ions allow the preparation of polynuclear compounds whose structures and magnetic properties are presented here. The influence of structural and chemical parameters on the magnitude of the singlet-triplet energy gap (J) in di-μ-hydroxocopper(II) complexes [LCu(OH)2CuL]2+ with L = 2,2′-bipyridine (bpy) and bpym is analyzed and discussed. Special attention is devoted to nature of the counterion which allows the preparation of hydroxo-bridge copper(II) cubane and double cubane type complexes where all the intramolecular magnetic inter…

Experimental and Theoretical Study of Dynamic Structural Transformations between Sensing Copper(II)-Uracil Antiferromagnetic and Metamagnetic Coordin…

2020

This paper describes the synthesis and characterization of several Copper(II)-uracil-1-propionic acid (UPrOH) coordination compounds, including the theoretical and experimental study of their cryst...

A distorted honeycomb motif in divalent transition metal compounds based on 4-phosphonbenzoic acid and exchange coupled Co(II) and Cu(II): synthesis,…

2013

The first example of a two-dimensional inorganic hybrid material with cobalt as an open-shell transition metal ion and 4-phosphonbenzoic acid as a linker is presented together with its copper analogue. For both metal ions the inorganic part consists of edge-sharing metal–oxygen octahedra leading to a metal honeycomb motif. The magnetic properties of the cobalt compound are reported together with those of the corresponding copper compound based on the remarkably six-coordinated copper(II) ions.

Copper-O2 reactivity of tyrosinase models towards external monophenolic substrates: molecular mechanism and comparison with the enzyme.

2011

The critical review describes the known dicopper systems mediating the aromatic hydroxylation of monophenolic substrates. Such systems are of interest as structural and functional models of the type 3 copper enzyme tyrosinase, which catalyzes the ortho-hydroxylation of tyrosine to DOPA and the subsequent two-electron oxidation to dopaquinone. Small-molecule systems involving μ-η²:η² peroxo, bis-μ-oxo and trans-μ-1,2 peroxo dicopper cores are considered separately. These tyrosinase models are contrasted to copper–dioxygen systems inducing radical reactions, and the different mechanistic pathways are discussed. In addition to considering the stoichiometric conversion of phenolic substrates, t…

Physicochemical Properties of Copper(II) Bis(2-ethylhexyl) Sulfosuccinate Reversed Micelles

1998

Abstract Measurements of some physicochemical properties (density, viscosity, conductance, UV–vis spectra, IR spectra) of the water/copper(II) bis(2-ethylhexyl) sulfosuccinate (Cu(DEHSS) 2 )/CCl 4 microemulsions, at a fixed surfactant molal concentration ([Cu (DEHSS) 2 ] = 0.05003 mol kg −1 ), as function of the molar ratio R ( R = [water]/[DEHSS − ]) have been performed at 25°C. Information on some structural and dynamical properties of the water-containing Cu(DEHSS) 2 reversed micelles and of their evolution with R are derived from the experimental results. The comparison with the same properties of water-containing sodium bis(2-ethylhexyl) sulfosuccinate reversed micelles allows to evide…