Copper Thiolate Complexes Research Articles

Photoluminescence in halogeno copper(Ⅰ) methyl thiolate polymers via in situ DMSO decomposition reaction

Five halogeno-copper thiolate coordination polymers, Cu12Cl6(SCH3)6(DMSO) 1, Cu3X(SCH3)2 (2, 4), and Cu2X(SCH3) (X = Br, I) (3, 5) were solvothermally prepared by employing DMSO, which is used as a thiolate source via in situ decomposition. The X-ray crystallographic data revealed one type of 3D network structure composed of Atlas spheres. Additionally, two types of 2D layered bromo/iodo isostructural complexes were found, and the differences between these two types are attributed to the different connection modes of their Cu3X2(SCH3)2 chains. Sharing the halogen atoms in Cu3X2(SCH3)2 chain or bridging the chains via additional copper atoms could lead to the formation of different layers with a Cu:X:SCH3 ratio of 3:1:2 or 2:1:1, respectively. The absorption and emission spectral data described the influence of the ratio and species of halogen elements in copper thiolate complexes. From the spectroscopic studies, long-lived phosphorescence was detected, the characteristic lifetime of which depends on the crystal internal structures as well as the constituent halogen atoms.

ChemInform Abstract: Copper‐Mediated C—H Activation/C—S Cross‐Coupling of Heterocycles with Thiols.

We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2'-bipyridine and Na(2)CO(3). We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimental results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bidentate ligand such as 2,2'-bipyridine; R: aryl or alkyl group) is the first reactive intermediate responsible for the observed organic transformation. Furthermore, our computational studies suggest a stepwise reaction mechanism based on a hydrogen atom abstraction pathway, which is more energetically feasible than many other possible pathways including β-hydride elimination, single electron transfer, hydrogen atom transfer, oxidative addition/reductive elimination, and σ-bond metathesis.

Copper-Mediated C–H Activation/C–S Cross-Coupling of Heterocycles with Thiols

We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2'-bipyridine and Na(2)CO(3). We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimental results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bidentate ligand such as 2,2'-bipyridine; R: aryl or alkyl group) is the first reactive intermediate responsible for the observed organic transformation. Furthermore, our computational studies suggest a stepwise reaction mechanism based on a hydrogen atom abstraction pathway, which is more energetically feasible than many other possible pathways including β-hydride elimination, single electron transfer, hydrogen atom transfer, oxidative addition/reductive elimination, and σ-bond metathesis.

Trace elements and rheumatoid arthritis (RA)--pathogenetic and therapeutic aspects.

Rheumatoid arthritis is characterized by increased activity of macrophages which produce toxic forms of oxygen. Such oxygen has been suggested as mediator also of rheumatoid inflammation. Gold accumulates in lysosomes of the macrophages and stabilizes lysosomal and other cell membranes leading to reduced liberation of toxic oxygen. Intracellular production of metallothionein can be induced. Zinc in high doses parenterally can immobilize macrophages and also induce metallothionein-like proteins. Copper and zinc are components of SOD which detoxifies oxygen, and copper-thiolate complexes are reported to be anti-inflammatory. The therapeutic effect of penicillamine and other thiols like aurothiomalate may also be related to an anti-oxidative action. Therapeutic induction of increased intracellular levels of glutathione or administration of selenium in such a form that it incorporates into glutathione-peroxidase and increases the efficacy of the enzyme may lead to accelerated metabolism of toxic oxygen.