Browsing by Subject "STATE AQUEOUS ORGANOMETALLICS"

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    Speciation of [Cp*2M2O5] in Polar and Donor Solvents
    (WILEY-V C H VERLAG GMBH) Sözen-Aktas, P; Del Rosal, I; Manoury, E; Demirhan, F; Lledós, A; Poli, R
    The speciation of compounds [Cp*2M2O5] (M=Mo, W; Cp*=pentamethylcyclopentadienyl) in different protic and aprotic polar solvents (methanol, dimethyl sulfoxide, acetone, acetonitrile), in the presence of variable amounts of water or acid/base, has been investigated by 1HNMR spectrometry and electrical conductivity. Specific hypotheses suggested by the experimental results have been further probed by DFT calculations. The solvent (S)-assisted ionic dissociation to generate [Cp*MO2(S)]+ and [Cp*MO3] takes place extensively for both metals only in water/methanol mixtures. Equilibrium amounts of the neutral hydroxido species [Cp*MO2(OH)] are generated in the presence of water, with the relative amount increasing in the order MeCN approximate to acetone
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    Rational, Facile Synthesis and Characterization of the Neutral Mixed-Metal Organometallic Oxides Cp2*MoxW6-xO17 (Cp* = C5Me5, x=0, 2, 4, 6)
    (WILEY-V C H VERLAG GMBH) Taban-Çaliskan, G; Agustin, D; Demirhan, F; Vendier, L; Poli, R
    The reaction of the bis(pentamethylcyclopentadienyl)pentaoxidodimetal complexes Cp*2M2O5 with four equivalents of Na2M'O-4 (M, M' = Mo, W) in acidic aqueous medium constitutes a soft and selective entry into neutral Lindqvist-type organometallic mixed-metal oxides Cp*2MoxW6-xO17 [x = 6 (1), 4 (2), 2 (3), 0 (4)]. The identity of the complexes is demonstrated by elemental analyses, thermogravimetric analyses and infrared spectroscopy. Thermal degradation of 1-4 up to above 500 degrees C leads to Mox/6W1-X/6O3. The molecular identity and geometry of compound 2 is further confirmed by a fit of the powder X-ray diffraction pattern with a model obtained from previously reported single-crystal X-ray structures of I and 4, with which 2 is isomorphous. DFT calculations on models obtained by replacing Cp* with Cp (I-IV) validate the structural assignments and assist in the assignment of the M,M'-O vibrations. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)