The Chemistry of Transition Metal Complexes Containing Catechol and Semiquinone Ligands

Coordination chemistry of soluble metal oxides of molybdenum and vanadium

Homoleptic, mononuclear transition metal complexes of 1,2-dioxolenes: Updating their electrochemical-to-structural (X-ray) properties

A rational approach to heterometallic cluster formation is described that uses incommensurate symmetry requirements at two different metals to control the stoichiometry of the assembly. Critical to this strategy is the proper design and synthesis of hybrid ligands with coordination sites selective toward each metal. The phosphino-catechol ligand 4-(diphenylphosphino)benzene-1,2-diol (H2L) possesses both hard catecholate and soft phosphine donor sites and serves such a role, using soft (C2-symmetric) and hard (C3-symmetric) metal centers. The ML3 catecholate complexes (M = FeIII, GaIII, TiIV, SnIV) have been prepared and characterized as C3-symmetry precursors for the stepwise assembly (aufbau) of heterometallic clusters. While the single-crystal X-ray structure of the Cs2[TiL3] salt shows a C1 mer-configuration in the solid -state, room-temperature solution NMR data of this and related complexes are consistent with either exclusive formation of the C3-fac-isomer with all PPh2 donor sites syn to each other...

Rational design and assembly of M2M′3L6 supramolecular clusters with C3h symmetry by exploiting incommensurate symmetry numbers

Synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region is a surface analytical technique that can provide direct insights into the localization and real-time mechanisms for the reduction of the (CrO4)2- chromate [Cr(VI)] species on surfaces of geologic materials. Time-resolved SR-FTIR spectra indicate that, in the presence of endoliths (mineral-inhabiting microorganisms), microbial reduction of Cr(VI) to Cr(III) compounds on basaltic mineral surfaces is the key mechanism of Cr(VI) transformation. It proceeds in at least a two-step reaction with Cr(V) compounds as possible intermediate products, with the reduction of Cr(VI) increasing during the concomitant biodegradation of a dilute organic vapor (toluene). Analyses of spatially resolved SR-FTIR spectra show that the maximum reduction of Cr(VI) to Cr(III) compounds occurs on surfaces densely populated by microorganisms. The oxidation state of Cr(III) compounds was confirmed by micro-x-ray absorption...

Real-Time Characterization of Biogeochemical Reduction of Cr(VI) on Basalt Surfaces by SR-FTIR Imaging

Salts of the new catecholato(2–)(cat) complexes [Ru(cat)3]3–, [Ir(cat)3]2–, [Re(cat)3]2–, [WO2(cat)2]2– and [W2O5(cat)2]2– are reported, a number of oxomolybdenum catecholato complexes reinvestigated and some reformulated. Infrared, Raman, and n.m.r. data are reported for the complexes.

Catecholato complexes of ruthenium, iridium, rhenium, molybdenum, and tungsten

Tropolonato complexes of osmium, iridium, platinum, molybdenum and tungsten, and the X-ray crystal structure of MoO2trop2

New complexes of the form trans-[OsO2L2]2– and UO2L·nH2O [H2L = adrenaline (H2ad), noradrenaline (H2nad), dopamine (H2dpm), dopa (H2dp), and isoproterenol (H2prot)] are reported, as are cis-[MO2L2]2–(L = nad, dp, prot for M = Mo or W, and ad for M = W), [MO2(Hdpm)2](M = Mo or W), and [Mo2O5(Had)2]. The structures of these species are discussed on the basis of their Raman, infrared, 1H, and 13C n.m.r. spectra.

Carol A. Pumphrey

Papers

Catecholato complexes of ruthenium, iridium, rhenium, molybdenum, and tungsten

Tropolonato complexes of osmium, iridium, platinum, molybdenum and tungsten, and the X-ray crystal structure of MoO2trop2

Complexes of osmium, uranium, molybdenum, and tungsten with the catechol amines adrenaline, noradrenaline, dopamine, dopa, and isoproterenol

Catecholato Complexes of Ruthenium, Iridium, Rhenium, Molybdenum, and Tungsten.

Complexes of Osmium, Uranium, Molybdenum, and Tungsten with the Catechol Amines Adrenaline, Noradrenaline, Dopamine, Dopa, and Isoproterenol.