Metal-Organic Cubane Cage with Trimethylplatinum(IV) Vertices.

Herein we describe the synthesis and characterization of the first platinum(IV) metal-organic cage [(MePt)(byp)](OTf) (), in which the organometallic moieties trimethylplatinum(IV) (PtMe) occupied the corners of a cubane structure and 4,4'-bipyridine ligands used as linkers. The first-principles density functional theory calculations showed that the highest occupied molecular orbitals were localized on the PtMe moieties, while the lowest unoccupied molecular orbitals were distributed on the organic linkers.

Five- and Six-Coordinated Silver(I) Complexes Formed by a Metallomacrocyclic Ligand with a "AuN" Donor Group: Observation of Pendulum and Linear Motions and Dual Phosphorescence.

The six-coordinated silver(I) complex [AuAg(μ-(PPh)py)(OTf)](OTf), (py = pyridine, OTf = CFSO), and the five-coordinated silver(I) complex [AuAg(acetone)(μ-(PPh)py)](PF), , were prepared by the reaction of the precursor complexes (OTf) and (PF), in which = [Au(μ-(PPh)py)], with 1 equiv of Ag(OTf) in dichloromethane and excess of Ag(PF) in a mixture of dichloromethane/acetone, respectively. Also, the five-coordinated silver(I) complex [AuAg(μ-(PPh)py)(py)(OTf)](OTf), , was obtained by the reaction of with pyridine. The clusters - were characterized using multinuclear NMR spectroscopy and elemental microanalysis.

Tetranuclear AuCu Clusters with Butterfly- and Planar-Shaped Metal Cores: Strong Rigidochromism Induced by Jahn-Teller Distortion in Two-Coordinated Gold(I) Centers.

Two tetranuclear AuCu cluster complexes [AuCu(μ-(PPh)py)(μ-OH)](PF), , and [AuCuCl(μ-(PPh) py)](OTf), , have been prepared by the reactions of precursor complexes [Au(μ-(PPh)py)](OTf), , and [Cu(μ-(PPh)py)(μ-SMe)(OTf)], , with [Cu(NCCH)]PF and AuCl(SMe), respectively. The crystal structures of complexes and were determined by X-ray crystallography, indicating a butterfly-shaped AuCu metal core for and a planar-shaped AuCu metal core for . In complex , the Cu atoms occupy the edge-sharing bond, while in complex , alternating Au and Cu atoms occupy the tetragon vertices.

Energetic basis of catalytic activity of layered nanophase calcium manganese oxides for water oxidation.

Previous measurements show that calcium manganese oxide nanoparticles are better water oxidation catalysts than binary manganese oxides (Mn3O4, Mn2O3, and MnO2). The probable reasons for such enhancement involve a combination of factors: The calcium manganese oxide materials have a layered structure with considerable thermodynamic stability and a high surface area, their low surface energy suggests relatively loose binding of H2O on the internal and external surfaces, and they possess mixed-valent manganese with internal oxidation enthalpy independent of the Mn(3+)/Mn(4+) ratio and much smaller in magnitude than the Mn2O3-MnO2 couple. These factors enhance catalytic ability by providing easy access for solutes and water to active sites and facile electron transfer between manganese in different oxidation states.

A very simple method to synthesize nano-sized manganese oxide: an efficient catalyst for water oxidation and epoxidation of olefins.

Nano-sized particles of manganese oxides have been prepared by a very simple and cheap process using a decomposing aqueous solution of manganese nitrate at 100 °C. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction spectrometry have been used to characterize the phase and the morphology of the manganese oxide. The nano-sized manganese oxide shows efficient catalytic activity toward water oxidation and the epoxidation of olefins in the presence of cerium(IV) ammonium nitrate and hydrogen peroxide, respectively.

Nano-sized layered aluminium or zinc-manganese oxides as efficient water oxidizing catalysts.

Nano-sized layered aluminium or zinc-manganese oxides were synthesized and characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectrometry, dynamic light scattering and atomic absorption spectroscopy. These oxides showed efficient water oxidizing activity in the presence of cerium(IV) ammonium nitrate as a non-oxo transfer oxidant. Amounts of dissolved manganese, zinc or aluminium, and water oxidation activities of these oxides were reported and compared with other manganese oxides.

Calcium manganese(IV) oxides: biomimetic and efficient catalysts for water oxidation.

CaMnO(3) and Ca(2)Mn(3)O(8) were synthesized and characterized by SEM, XRD, FTIR and BET. Both oxides showed oxygen evolution activity in the presence of oxone, cerium(IV) ammonium nitrate and H(2)O(2). Oxygen evolution from water during irradiation with visible light (λ > 400 nm) was also observed upon adding these manganese oxides to an aqueous solution containing tris(2,2'-bipyridyl) ruthenium(II), as photosensitizer, and chloro pentaammine cobalt(III) chloride, as electron acceptor, in an acetate buffer.

Nano-size amorphous calcium-manganese oxide as an efficient and biomimetic water oxidizing catalyst for artificial photosynthesis: back to manganese.

A nano-size amorphous calcium-manganese oxide shows efficient water oxidation activity in the presence of cerium(IV) ammonium nitrate.