25523-43-7Relevant articles and documents
Immobilized Cobalt Bis(benzenedithiolate) Complexes: Exceptionally Active Heterogeneous Electrocatalysts for Dihydrogen Production from Mildly Acidic Aqueous Solutions
Eady, Shawn C.,MacInnes, Molly M.,Lehnert, Nicolai
, p. 11654 - 11667 (2017)
A series of cobalt bis(benzenedithiolate) complexes with varying benzenedithiolate (general abbreviation: bdt2-) ring substitutions (S2C6X42-) were prepared and adsorbed on inexpensive electrodes composed of (a) reduced graphene oxide (RGO) electrodeposited on fluorine-doped tin oxide (FTO) and (b) highly ordered pyrolytic graphite (HOPG). The catalyst-adsorbed electrodes are characterized by X-ray photoelectron spectroscopy. Catalyst loading across the ligand series improved notably with increasing halide substitution [from 2.7 × 10-11 mol cm-2 for TBA[Co(S2C6H4)2] (1) to 6.22 × 10-10 mol cm-2 for TBA[Co(S2C6Cl4)2] (3)] and increasing ring size of the benzenedithiolate ligand [up to 3.10 × 10-9 mol cm-2 for TBA[Co(S2C10H6)2] (6)]. Electrocatalytic analysis of the complexes immobilized on HOPG elicits a reductive current response indicative of dihydrogen generation in the presence of mildly acidic aqueous solutions (pH 2-4) of trifluoroacetic acid, with overpotentials of around 0.5 V versus SHE (measured vs platinum). Rate constant (kobs) estimates resulting from cyclic voltammetry analysis range from 24 to 230 s-1 with the maximum kobs for TBA[Co(S2C6H2Cl2)2] (2) at an overpotential of 0.59 V versus platinum. Controlled-potential electrolysis studies performed in 0.5 M H2SO4 at -0.5 V versus SHE show impressive initial rate constants of over 500 s-1 under bulk electrolysis conditions; however, steady catalyst deactivation over an 8 h period is observed, with turnover numbers reaching 9.1 × 106. Electrolysis studies reveal that halide substitution is a central factor in improving the turnover stability, whereas the ring size is less of a factor in optimizing the long-term stability of the heterogeneous catalyst manifolds. Catalyst deactivation is likely caused by catalyst desorption from the electrode surfaces.
RUTHENIUM COMPLEXES USEFUL FOR CATALYZING METATHESIS REACTIONS
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Paragraph 0086, (2018/05/27)
Compound of formula (4) or formula (5), wherein L is a neutral ligand, preferably a nitrogen-containing heterocyclic carbene (NHC) such as carbene containing at least two nitrogen atoms, a cyclic aminoalkyl carbene (CAAC) or a bicyclic aminoalkyl carbene (BICAAC); R1, R3, R4, R5, R6, R7, R8, R9, R10 and R11 are, independently, H, unbranched or branched C1-20 alkyl, C5-9 cycloalkyl, unbranched or branched C1-20 alkoxy, optionally bearing one or more halogen atoms, respectively; or aryl, optionally substituted with one or more of unbranched or branched C1-20 alkyl, C5-9 cycloalkyl, unbranched or branched C1-20 alkoxy, aryl, aryloxy, unbranched or branched C1-20 alkylcarbonyl, arylcarbonyl, unbranched or branched C1-20 alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl, cyano, nitro, amido, aminosulfonyl, N-heteroarylsulfonyl, unbranched or branched C1-20 alkylsulfonyl, arylsulfonyl, unbranched or branched C1-20 alkylsulfinyl, arylsulfinyl, unbranched or branched C1-20 alkylthio, arylthio, sulfonamide, halogen or N(Ry)(Rz), wherein Ry and Rz are independently selected from H and C1-20 alkyl: R2 is H, unbranched or branched C1-20 alkyl.
CATALYSTS FOR EFFICIENT Z-SELECTIVE METATHESIS
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Paragraph 00608-00609, (2015/01/09)
The present application provides, among other things, compounds and methods for metathesis reactions. In some embodiments, provided compounds promote highly efficient and highly Z-selective metathesis. In some embodiments, provided compounds and methods are particularly useful for producing allyl alcohols. In some embodiments, provided compounds have the structure of formula I. In some embodiments, provided compounds comprise ruthenium, and a ligand bonded to ruthenium through a sulfur atom.
