Crystals of a new dimeric chloride-bridged cuprate(II) derived from pyridine-2,4-di-carb-oxy-lic acid were obtained solvothermally in the presence of piperazine and hydro-chloric acid. The crystal structure determination of the title salt, (C4H12N2)[Cu2(C7H4NO4)2Cl4], revealed one of the carboxyl groups of the original pyridine-2,4-di-carb-oxy-lic acid ligand to be protonated, whereas the other...

Anaerobic reactions of Rhus vernicifera laccase and its type-2 copper-depleted derivatives with hexacyanoferrate(II) were investigated by absorption and e.s.r. spectroscopy. When native laccase was treated with excess hexacyanoferrate(II), the type-1 and type-2 coppers were immediately reduced and the e.s.r. signal due to type-3 copper was transiently observed. After incubation, a novel e.s.r. ...

The crystal structure of the title salt, [Cu(ClO4)(C8H20N4)]ClO4, is reported. The CuII ion exhibits a square-pyramidal geometry and is coordinated by the four N atoms of the neutral 1,4,7,10-tetra-aza-cyclo-dodecane (cyclen) ligand and an O atom from one perchlorate anion, with the second perchlorate ion hydrogen-bonded to one of the amine N atoms of the cyclen ligand. Additional N-H⋯O hydroge...

Thiol esters and boronic acids react to produce ketones under aerobic conditions in the presence of catalytic quantities of a CuI or CuII salt. The reaction occurs at reasonable rates between room temperature and 50 degrees C at neutral pH using thiol esters derived from bulky 2 degrees amides of thiosalicylamides such as those based on N-tert-butyl-2-mercaptobenzamide. In this mechanistically ...

The lowering of the CuII→CuI reduction temperature for subnano CuO particles (ca. 1 nm) was demonstrated, compared to nanoparticles, which monitored by in situ XAFS H2-TPR experiments. enhanced performance with a release atomic oxygen from copper oxide is attributed surface-strained structure and elongation Cu−O bonds.

A method was developed for the separation of CdII, PbII, PtII, CoII, NiII, BiIII, CrII, CuII and HgII bis(2-hydroxyethyl)dithiocarbamate (HEDTC) complexes by micellar electrokinetic capillary chromatography. The complexes were formed by pre-capillary reaction of the metal ions with an excess of the ligand and then separated using a 100 mm borate buffer (pH 9.2) containing 4% methanol (v/v), 10 ...

In the title compound, [Cu(C7H3NO4)(C3H4N2)(H2O)]·2H2O, the CuII atom is coordinated by three O atoms and two N atoms, provided by a tridentate pyridine-2,6-di-carboxyl-ate (pdc), one pyrazole and one water ligand, forming a slightly distorted square-pyramidal geometry [range of O-Cu-O and O-Cu-N bond angles = 79.55 (8)-166.22 (10)°]. The water mol-ecule is positioned at the apical position. In...

The title dinuclear copper(II) complex [Cu2(C18H16Br2N2O4S2)2] was prepared by direct synthesis of a dianionic Schiff base derived from 5-bromo-salicyl-aldehyde and cyste-amine. The discrete mol-ecules lie across inversion centers and crystallize with two di-methyl-formamide (DMF) mol-ecules of crystallization. The unique CuII ion is four-coordinated by two tetra-dentate Schiff base ligands in ...