The homogeneous catalysis of water oxidation by transition-metal complexes has experienced spectacular development over the last five years. Practical energy-conversion schemes, however, require robust catalysts with large turnover frequencies. Herein we introduce a new oxidatively rugged and powerful dinuclear water-oxidation catalyst that is generated by self-assembly from a mononuclear catal...

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-( - )-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. Th...

A series of benzobisimidazolium salts 1a-d has been prepared by tetraalkylation of benzobisimidazol. The salts 1a-d react with two equivalents of [Pt(Cl)2dppe] in the presence of 2.2 equivalents of sodium acetate to yield the dinuclear biscarbene complexes 2a-d. Under the same reaction conditions, the benzobisimidazolium salts react with only one equivalent of [Pt(Cl)2dppe] and one equivalent o...

The copper-catalyzed 1,3-dipolar cycloaddition of an azide to a terminal alkyne (CuAAC) is one of the most popular chemical transformations, with applications ranging from material to life sciences. However, despite many mechanistic studies, direct observation of key components of the catalytic cycle is still missing. Initially, mononuclear species were thought to be the active catalysts, but l...

In the dinuclear title compound, [Zn(2)(C(14)H(12)N(3)O(2)S)(2)Cl(2)]·4C(3)H(7)NO, the two monodeprotonated Schiff base ligands N,O,S:O-chelate to Zn atoms. The formally negatively charged O atom involved in chelation also serves as a bridge. The O, O', N and S atoms comprise a square, and the Cl atom the apex of a square pyramid surrounding each metal atom. The solvate dimethyl-formamide mol-e...

Z. Naturforsch. 54 b, 1147-1154 (1999); received June 2, 1999 Dinuclear Complexes, NIR Dyes, Cobalt, Tripodal Ligands, Bridging Ligands Dinuclear Co(III) complexes of the type [(triphos)Co(C6X2Z' Z2Z3Z4)Co(triphos)]2+ (Z1 ~4 = O, NR, S; R = H, Me; X = H, Cl, Br, I; 1 62+) have been prepared and characterized by MS, IR, NMR, cyclovoltammetric and UV/VIS/NIR measurements and by X-ray analyses (12...