Syngas and HDS catalysts derived from sulphido bimetallic clusters
TL;DR: In this article, the authors show that sulphido bimetallic clusters are excellent precursors for the formation of uniform catalytic surfaces, which are transformed to surface oxo-ensembles which are active for CO hydrogenation and HDS of organic sulphur compounds.
About: This article is published in Polyhedron.The article was published on 1988-01-01 and is currently open access. It has received 44 citations till now. The article focuses on the topics: Thiophene & Catalysis.
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600 citations
TL;DR: In this article, the authors show that the catalytic activity is directly proportional to the increase of surface area of the sulfide phases (Co9S8 and MoS2) present in Co-promoted MoS 2 unsupported catalysts.
149 citations
TL;DR: In this article, a review article is presented and outline new approaches to sulfur chemistry from the organometallic point of view Reactive cyclopentadienyl-transition metal fragments incorporate elemental sulfur to give polynuclear sulfur-rich complexes, which can contain either mono-, di- or polysulfido ligands or several such ligands in combined form.
Abstract: Metal-sulfur centers play an important role in the activity of metalloproteins in enzymatic catalysis and the activity of metal sulfides as heterogeneous catalysts The systematic search for M[BOND]S model compounds led to the discovery of an interesting and novel structural chemistry, which stems from the numerous coordination possibilities of sulfur ligands The intention of this review article is to present and outline new approaches to sulfur chemistry from the organometallic point of view Reactive cyclopentadienyl-transition metal fragments incorporate elemental sulfur to give polynuclear sulfur-rich complexes, which can contain either mono-, di- or polysulfido ligands or several such ligands in combined form The versatile structural chemistry of the complexes formed and their reactivity towards organic, inorganic and organometallic compounds are discussed, and examples of some simple and rational procedures for their synthesis starting from cyclopentadienylcarbonyl- and cyclopentadienylhydrido-complexes are outlined Their reactivity is manifested in numerous metal- and ligandcentered reactions Finally the, albeit far less extensive, complex chemistry of the other chalcogens (O, Se, Te) is also considered for comparison, thus providing a more detailed survey of particular aspects of this area of chemistry
130 citations
TL;DR: In this article, the kinetics of the reaction of a series of aromatic and aliphatic thiols with cluster 1 were determined, and the rate determining step of the desulfurization reaction is the initial association of the thiol to the cluster.
Abstract: The kinetics of the reaction of a series of aromatic and aliphatic thiols with cluster 1 were determined. These reactions form cluster 2 and the arene or alkane corresponding to the thiol: Cp‘2Mo2Co2S3(CO)4 (1) + RSH → Cp‘2Mo2Co2S4(CO)2 (2) + RH + 2CO. These reactions are first order in thiol and first order in cluster 1 with appreciable negative entropies of activation. These data suggest that the rate determining step of the desulfurization reaction is the initial association of the thiol to the cluster. The more nucleophilic thiolate anions react with 1 at −40 °C to form an adduct in which the thiolate anion is bound η1 to the Co atom. At −25 °C, the initial adduct rearranges to a fluxional μ2, η1-bound thiolate. The fluxional process is proposed to involve a concerted “walking” of the thiolate and a μ2-bound sulfide ligand on the surface of the cluster. Near 35 °C, the thiolate−cluster adduct undergoes C−S bond homolysis to give the paramagnetic anion of cluster 1 and the phenyl or alkyl radical. The...
112 citations
TL;DR: In this paper, cuboidal clusters of molybdenum and tungsten with M2M′2S4 and M3M′Q4 central units that incorporate a first-row transition metal atom (M′) are discussed.
Abstract: Transition metal cluster chalcogenides with cubane-type structures are relevant to our understanding of several industrial and biological catalytic processes. Recent advances in cluster chemistry owe much to the development of rational synthetic approaches, an aspect that is emphasised in this review which focuses on cuboidal clusters of molybdenum and tungsten (M) with M2M′2S4 and M3M′Q4 (Q = S, Se) central units that incorporate a first-row transition metal atom (M′). Special attention has been paid to the non-aqueous chemistry of these compounds. The structural features of these complexes are discussed in relation to their electronic structures within the framework of molecular orbital theory, spectroscopic, magnetic and electrochemical experimental data. Finally, the importance of these clusters in catalysis, nonlinear optics and in the formation of supramolecular adducts is discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
108 citations
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TL;DR: In this paper, the structure and type of phases present in sulfided alumina-supported, as well as unsupported, Co-Mo catalysts is obtained from in situ Mossbauer emission spectroscopy (MES) studies.
563 citations
514 citations
TL;DR: In this paper, the authors investigated the nature of Co in calcined CoMo Al 2 O 3 catalysts and the changes that occur upon sulfiding by Mossbauer emission spectroscopy (MES).
116 citations