نتایج جستجو برای: molybdenum compounds
تعداد نتایج: 239382 فیلتر نتایج به سال:
Treatment of indium trichloride with three equivalents of the cyclopentadienyliron carbonyl anions, [Fe(C O )2(?7-C5H4R)] (R = H, Me) affords the tri-iron indium com plexes [In{Fe(C O )2(//-C5H 4R )},] (R = H. Me) as dark red crystalline materials. Both compounds were characterized by spectroscopic and analytical methods. Infrared spectroscopy indicates that both com plexes are undissociated in...
The sonochemical decomposition of volatile organometallic compounds produces high surface area solids that consist of agglomerates of nanometer clusters. For iron pentacarbonyl and tricarbonylnitrosylcobalt, nanostructured metals and alloys are formed; for molybdenum hexacarbonyl, the metal carbide is produced. These sonochemically produced nanostructured solids are active heterogeneous catalys...
The development of a protocol for the reductive functionalization of amides into N-sulfonylformamidines is reported. The one-pot procedure is based on a mild catalytic reduction of tertiary amides into the corresponding enamines by the use of Mo(CO)6 (molybdenum hexacarbonyl) and TMDS (1,1,3,3-tetramethyldisiloxane). The formed enamines were allowed to react with sulfonyl azides to give the tar...
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...
The sulfate-reducing bacterium Desulfococcus multivorans uses various aromatic compounds as sources of cell carbon and energy. In this work, we studied the initial steps in the aromatic metabolism of this strictly anaerobic model organism. An ATP-dependent benzoate coenzyme A (CoA) ligase (AMP plus PPi forming) composed of a single 59-kDa subunit was purified from extracts of cells grown on ben...
Formate dehydrogenase molybdenum and tungsten sites--observation by EXAFS of structural differences.
Preliminary EXAFS data has been collected on the molybdenum (K-edge) in C. pasteurianum formate dehydrogenase and the tungsten (LIII-edge) in C. thermoaceticum formate dehydrogenase. In the presence of dithionite, the tungsten enzyme was devoid of W = O bonds, and exhibited average W-(O, N) and W-S bond lengths of 2.13 +/- 0.03 A and 2.39 +/- 0.03 A, respectively. In sharp contrast, the C. past...
Microbial degradation of N-heterocyclic compounds, including xanthine, quinoline, nicotinate, and nicotine, frequently requires molybdenum hydroxylases. The intramolecular electron transfer chain of molybdenum hydroxylases consists of a molybdenum cofactor, two distinct [2Fe-2S] clusters, and flavin adenine dinucleotide. 3-Succinoylpyridine monooxygenase (Spm), responsible for the transformatio...
Background: Technetium-99m radioisotope is the backbone of any nuclear medicine institute. This radioisotope is acquired by the elution of Molybdenum-99/Technetium-99m generator which emits 141 keV gamma ray and having 6.04 hour half-life. Occasionally the contents of Molybdenum-99 may mix up with elute, which may affect image quality and patients may receive higher doses than recommended. This...
X-ray absorption spectroscopy (XAS) is a widely used experimental technique capable of selectively probing the local structure around an absorbing atomic species in molecules and materials. When applied to heavy elements, however, the quantitative interpretation can be challenging due to the intrinsic spectral broadening arising from the decrease in the core-hole lifetime. In this work we have ...
BACKGROUND Chewing stick (miswak Salvadora persica L.) is an effective tool for oral hygiene. It possessed various biological properties including significant antibacterial and anti-fungal effects. In the present study, we evaluated the antioxidant compounds in miswak. METHOD Miswak root was extracted with 80% methanol. Methanol extract as antioxidant was evaluated by using DPPH, ABTS and pho...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید