Reaction of a tantalum alkylidene complex with dinuclear metal carbonyls: Formation of C[sub 3] ligands

Journal Article · Fri Jan 29 04:00:00 EST 1993 · Science (Washington, D.C.); (United States)

OSTI ID:6837394

Proulx, G; Bergman, R G ^[1]

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1. Univ. of California, Berkeley (United States)

The mechanisms of reactions that deoxygenate carbon monoxide (CO) and convert it into longer chain hydrocarbons are not well understood. A series of reactions between early' and late' transition metal complexes that result in CO coupling reactions in a homogeneous solution are reported. In one example, the Schrock tantalum-methylene complex ([eta][sup 5]-C[sub 5]H[sub 5])[sub 2]Ta(CH[sub 2])(CH[sub 3]) reacts with the dinuclear metal carbonyls Co[sub 2](CO)[sub 8] and Fe[sub 2](CO)[sub 9] in a novel fashion to yield a C[sub 3]H[sub 2]O[sub 2] ligand bridging three metal centers. Reaction of the tantalum-methylene complex with Re[sub 2](CO)[sub 10] leads to an even more substantial change in which extensive rearrangement along with three-carbon coupling occurs. An oxygen atom is removed from one CO group, leading to the novel oxotantalum compound ([eta][sup 5]-C[sub 5]H[sub 5])[sub 2](CH[sub 3])Ta[double bond]O. Simultaneously, the carbon atom from the transformed CO couples with two CH[sub 2] groups initially bound to tantalum and the CH[sub 2] hydrogens are rearranged to produce a CH[sub 3]-CC ligand. Low-temperature nuclear magnetic resonance and isotope tracer experiments have provided preliminary information about the mechanisms of these unusual carbon-carbon bond-forming reactions. 12 refs., 3 figs.

• OSTI ID: 6837394
• Journal Information: Science (Washington, D.C.); (United States), Journal Name: Science (Washington, D.C.); (United States) Vol. 259:5095; ISSN SCIEAS; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COBALT COMPLEXES
COMPLEXES
ELEMENTS
FLUIDS
GASES
HYDROCARBONS
IRON COMPLEXES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
REACTION INTERMEDIATES
RHENIUM COMPLEXES
SYNTHESIS
SYNTHESIS GAS
TRANSITION ELEMENT COMPLEXES