In this study, a new recoverable catalyst for the epoxidation of olefins was developed using a layered polysiloxane as a support for immobilizing  (salen) molybdenum(VI) complex by electrostatic interaction between the surface of the solid support and the electrically charged molybdenum complex. Characterization of the heterogeneous catalyst by Fourier transform infrared, XRD,1H NMR,...

fio = atomic transition oscillator strength g = linewidth distribution function, sec We have demonstrated the use of laser-induced flug = energy-averaged Gaunt factor orescence (LIF) to monitor the charge-exchange ion 9i = degeneracy for atomic level i erosion of the molybdenum accelerator electrode in h = Planck's constant, J sec ion thrusters. This real-time, nonintrusive method h = Planck's ...

this paper focused on a simple approach for synthesis of molybdenum oxide (moo3) nanoparticles and reports a facile route for synthesis of such nanoparticles, using microwave irradiation as a homogenous and powerful source of heating, using ethylene glycol as the solvent and heating medium. for more investigations, besides microwave heating, the obtained solutions were also treated by conventio...

The possibility of selective leaching process was investigated during molybdenite flue dust leaching to recover its rhenium content. The results show that addition of alcohols to water makes the medium less favorable for molybdenum transfer into aqueous phase. On the other hand, addition of small amounts of alcohols (5-15%) makes a noticeable separation of rhenium over molybdenum, but by increa...

Substitutions of trans-Na(Him)[Mo(2)O(4)(ox)(2)(H(2)O)(2)]·H(2)O (1) and trans-(Him)(2)[Mo(2)O(4)(ox)(2)(H(2)O)(2)] (2) with imidazole result in the formation of the mixed-ligand molybdenum complexes cis-Na(2)[Mo(2)O(4)(ox)(2)(im)(2)]·4.5H(2)O (3), cis-K(2)[Mo(2)O(4)(ox)(2)(im)(2)]·3H(2)O (4), respectively (H(2)ox = oxalic acid; im = imidazole). Further reduction of cis-K(2)[Mo(2)O(4)(ox)(2)(im...

The molybdenum center of xanthine oxidase has been examined by resonance Raman spectroscopy. Making use of the long-wavelength absorption of the reduced molybdenum center in complex with violapterin (the product of enzymic action of lumazine), resonance Raman spectra were obtained using laser excitation at 676.4 nm. Several internal vibrational modes of violapterin were found to be resonance-en...

www.sciencemag.org SCIENCE VOL 327 1 JANUARY 2010 7 COVER Crystal structure of a molybdenum oxide nanowheel, 2.6 nanometers in diameter, around a smaller molybdenum oxide cluster. Miras et al. (page 72; related Perspective page 38) used a controlled-flow reactor to show that the central core serves as a transient template for the self-assembly of the nanowheel and is ultimately ejected to yield...

We studied the effects of molybdenum, vanadium, and tungsten on the diazotrophic growth of Methanococcus maripaludis. Mo stimulated growth, with a maximal response at 4.0 microM, while V had no effect at any concentration tested. W specifically inhibited diazotrophic growth in the presence of Mo. Coupling the results of our analysis and other known metal requirements with phylogenies derived fr...

Dimethyl sulphoxide reductase was purified from the photosynthetic bacterium Rhodobacter capsulatus. The enzyme is composed of a single polypeptide of Mr 82,000 and contains a pterin-type molybdenum cofactor as the only detectable prosthetic group. The oxidized molybdenum cofactor of dimethyl sulphoxide reductase is a weak chromophore and exhibits broad absorption bands in the u.v.-visible-abso...