In natural photosynthesis, the oxygen evolving center is a tetranuclear manganese cluster stabilized by amino acids, water molecules and counter ions. However, manganese complexes are rarely exhibiting catalytic activity in water oxidation conditions. This is also true for the family of water oxidation catalysts (WOCs) obtained from POM chemistry. We have studied the activity of the tetranuclea...

Five new tetranuclear complexes based on an 8-hydroxyquinoline Schiff base derivative and the β-diketone coligand, [Ln4(acac)4L6(μ3-OH)2]·CH3CN·0.5CH2Cl2 (Ln = Gd (1), Tb (2), Dy (3), Ho (4) and Er (5); HL = 5-(benzylidene)amino-8-hydroxyquinoline; acac = acetylacetonate) have been synthesized, and structurally and magnetically characterized. Complexes 1-5 have similar tetranuclear structures. ...

The structures of the tetranuclear silver(I), [Ag4(hpp)4], and the dinuclear gold(II), [Au2(hpp)2Cl2], (hpp = 1,3,4,6,7,8-hexahydro-pyrimido[1,2-a]pyrimidinate) guanidinate-like bases are reported and show a silver-silver distance of 2.8614(6) A and a gold-gold distance of 2.4752(9) A, the shortest Au-Au bond heretofore reported.

A solvothermally derived tetranuclear cobalt(II) complex, [Co(4)(phen)(4)Cl(8)] (phen = phenanthroline), featuring a zig-zag backbone of {Co(μ(2)-Cl)(2)Co} planes, exhibits ferromagnetic exchange and slow relaxation of the magnetization and represents the first Co SMM with a linear core structure.

Reaction of TlPF(6) with the Cr(III) complex fac-[CrCl(3)(NPN)] (NPN = bis(2-picolyl)phenyl phosphine) did not lead to precipitation of TlCl but rather to addition of the Tl(+) cation to the CrCl(3) moiety, which resulted in a pseudo-dimeric adduct which has an unusual tetranuclear centrosymmetric structure in the solid state.

The paper reports the synthesis and characterisation of a series of flexible di-bidentate bridging ligands in which two 4-methyl-2,2'-bipyridine groups are linked at the 4'-position by polymethylene (bb(n)), linear polyether (bbO(n)) or linear alkylamine (bbN(n)) chains of varying length (n). The enantiomers (ΔΔ/ΛΛ) of the rac forms of the ruthenium(ii) dinuclear complexes incorporating these l...

A series of inert tri- and tetra-nuclear polypyridylruthenium(II) complexes that are linked by the bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane ligand ("bb(n)" for n = 10, 12 and 16) have been synthesised and their potential as antimicrobial agents examined. Due to the modular nature of the synthesis of the oligonuclear complexes, it was possible to make both linear and non-linear tetranuclear r...

Five new complexes were obtained from solution or hydrothermal reactions of M(OAc)(2) (M = Mn, Cu and Cd) or CuCl(2) with 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (abpt) and NaN(3) or 1,3,5-benzenetricarboxylic acid (btcH(3)) in different molar ratios. Structural analysis reveals that Cd(abpt) units in [Cd(abpt)(mu(1,1)-N(3))(2)](n) (1) are bridged by double mu(1,1) end-on (EO) azides into ...