Showing papers by "Edward I. Stiefel published in 1983"

Novel alkyne reactions with binuclear molybdenum-sulfur complexes: structure of the dimethyl acetylenedicarboxylate adduct of dioxobis(dithioxo)di-.mu.-thiodimolybdate(2-) ion ([Mo2O2(.mu.-S)2(S2)2]2-)

Abstract: Structure cristalline par diffraction RX du compose [N(C 2 H 5 ) 4 ] 2 Mo 2 O 2 (μ•S) 2 (S 2 C 2 (CO 2 CH 2 ) 2 . Formation de cycle metallodithia-2,3 cyclopentene-4. Coordination pyramidale a base carree autour des atomes Mo. (groupe Pnma avec a=18,314, b=25,358 et c=8,916 A, Z=4)

Complexes containing the Mo2O52+ core: preparation, properties and crystal structure of Mo2O5[(CH3)2NCH2CH2NHCH2C(CH3)2S]2

Abstract: Preparation de Mo 2 O 5 L 2 , le cordinat L est un monoanion tridente avec un donneur thiolate. Spectres RMN de 17 O et IR. Structure cristalline

Hydrotreating using self-promoted molybdenum and tungsten sulfide catalysts formed from bis(tetrathiometallate) precursors

Abstract: Hydrocarbon feeds are upgraded by contacting same, at elevated temperature and in the presence of hydrogen, with a self-promoted catalyst formed by heating one or more carbon-containing, bis(tetrathiometallate) catalyst precursor salts selected from the group consisting of (NR 4 ) 2 [M(WS 4 ) 2 ], (NR 4 ) x [M(MoS 4 ) 2 ] and mixtures thereof wherein R is one or more alkyl groups, aryl groups or mixture thereof, wherein promoter metal M is covalently bound in the anion and is Ni, Co or Fe and wherein x is 2 if M is Ni and x is 3 if M is Co or Fe composite in a non-oxidizing atmosphere in the presence of sulfur, hydrogen, and a hydrocarbon to form said supported catalyst.

Self-promoted molybdenum and tungsten sulfide hydrotreating catalysts from bis(tetrathiometallate) precursors

Abstract: Self-promoted molybdenum and tungsten sulfide hydrotreating catalyst are formed by heating one or more carbon-containing, bis(tetrathiometallate) catalyst precursor hydrogen with a supported, self-promoted catalyst salts selected from the group consisting of (NR4)2 [M(WS4)2 ], (NR4)x [M(MoS4)2 ] and mixtures thereof wherein R is one or more alkyl groups, aryl groups or mixture thereof, wherein promoter metal M is convalently bound in the anion and is Ni, Co or Fe and wherein x is 2 if M is Ni and x is 3 if M is Co or Fe in a non-oxidizing atmosphere in the presence of sulfur hydrogen, and hydrocarbon.

Multisulfur Metal Sites in Enzymes, Complexes, Clusters, and Solids: Possible Relevance for Nitrogenase

Abstract: This volume deals with biological nitrogen fixation and chemical systems which may offer analogy with or insight into the biological process. This chapter deals with certain biochemical and chemical systems which have not been studied specifically in the context of the nitrogen fixation problem. Rather, recent results in the areas non-nitrogenase Mo enzymes and the coordination and solid state chemistry of molybdenum are discussed. This chemistry reveals some of the structural, spectroscopic and mechanistic possibilities which present themselves when multisulfur metal sites are present.