Characterization and reaction studies of dimeric molybdenum(III) complexes with bridging dithiolate ligands. Catalytic reduction of acetylene to ethylene
The complexes (C/sub 5/H/sub 5/MoSC/sub n/H/sub 2n/S)/sub 2/ (where n = 2 and 3) have been prepared by the reaction of ethylene sulfide and propylene sulfide, respectively, with C/sub 5/H/sub 5/MoH(CO)/sub 3/ or with (C/sub 5/H/sub 5/Mo(CO)/sub 3/)/sub 2/. Cyclic voltammetry shows that each complex undergoes two reversible oxidations at 0.13 and 0.79 V vs. SCE (in acetonitrile with 0.1 M Bu/sub 4/NBF/sub 4/). Both the one-electron and two-electron oxidation products have been synthesized and characterized by spectral and magnetic data. Electrochemical data for the oxidized complexes support the conclusion that the complexes have the same gross structural features in all three oxidation states. A single crystal of the monocation (C/sub 5/H/sub 5/MoSC/sub 3/H/sub 6/S)/sub 2/BF/sub 4/ has been characterized by an x-ray diffraction study. The compound crystallizes in the space group C2/c with a = 18.266 (1) A, b = 9.206 (4) A, c = 12.911 (5) A, ..beta.. = 100.83 (3)/sup 0/, and V = 2128 A/sup 3/. The metal ions of the cation are bridged by two 1,2-propanedithiolate ligands. The four sulfur atoms of these ligands form a plane which bisects the metal-metal distance. The neutral dimeric complexes undergo a unique reaction with alkenes and alkynes in which the hydrocarbon portion of the bridging dithiolate ligands is exchanged. The reaction has been characterized with olefinswith both electron-withdrawing and electron-donating substituents. When (C/sub 5/H/sub 5/MoSC/sub 2/H/sub 4/S)/sub 2/ (1) is reacted with acetylene at 25/sup 0/C, ethene is produced and the complex (C/sub 5/H/sub 5/MoSC/sub 2/H/sub 2/S)/sub 2/ is isolated. The latter complex is reduced by hydrogen (2 atm) at 60/sup 0/C to re-form 1. The utility of these reactions in the catalytic reduction of acetylene to ethylene has been investigated. The role of the sulfur ligands in this catalytic cycle is discussed. 50 references, 2 figures, 5 tables.
- Research Organization:
- Univ. of Colorado, Boulder
- OSTI ID:
- 6015331
- Journal Information:
- J. Am. Chem. Soc.; (United States), Vol. 101:18
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKENES
CHEMICAL REACTIONS
ALKYNES
BORON COMPLEXES
CATALYTIC EFFECTS
OXIDATION
STRUCTURAL CHEMICAL ANALYSIS
HYDROGEN
MOLYBDENUM COMPLEXES
BOND ANGLE
BOND LENGTHS
BRIDGES
CATALYSTS
CHEMICAL PREPARATION
CRYSTAL STRUCTURE
DIMERS
EXPERIMENTAL DATA
INFRARED SPECTRA
ISOLATED VALUES
LIGANDS
MAGNETIC SUSCEPTIBILITY
MASS SPECTRA
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORGANIC SULFUR COMPOUNDS
SPACE GROUPS
VOLTAMETRY
X-RAY DIFFRACTION
COHERENT SCATTERING
COMPLEXES
CRYOGENIC FLUIDS
DATA
DATA FORMS
DIFFRACTION
ELEMENTS
FLUIDS
HYDROCARBONS
INFORMATION
MAGNETIC PROPERTIES
MAGNETIC RESONANCE
MECHANICAL STRUCTURES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
RESONANCE
SCATTERING
SPECTRA
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
400201 - Chemical & Physicochemical Properties