Mechanistic studies of carbon monoxide reduction. Progress report

Technical Report · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6766371

Geoffroy, G L

Progress in several areas has been made during the last three years of this research. One of the most significant findings has been the demonstration of CO insertion into ..mu..-CH/sub 2/ bonds in Os/sub 3/ clusters to yield ketene derivatives. This reaction readily occurs for Os/sub 3/(CO)/sub 11/(..mu..-CH/sub 2/), 1, to yield the ketene cluster Os/sub 3/(CO)/sub 12/(..mu..-CH/sub 2/CO), 2, which has been crystallographically characterized. Mechanistic studies showed that the incorporated CO came from one of the original cluster CO's and not from exogeneous CO. Also important is the demonstration that the ketene ligand in 2 can be hydrogenated to give CH/sub 3/CHO. Other aspects of the derivative chemistry of cluster 1 have been examined. It reacts with SO/sub 2/ to give a sulfene-bridged cluster and with halides and axide ion to give clusters of the form (Os/sub 3/(CO)/sub 10/(..mu..-CH/sub 2/)(..mu..-X))/sup -/ with X=Cl,Br,I, and NCO. These also insert CO into the metal-methylene bonds to give ketene derivatives, except that the insertions are much faster than the reaction of CO with 1, demonstrating a unique halide promoting effect on the methylene to ketene conversion. Formyl, acyl, carbene, and hydride derivatives of the bis(nitrene) cluster Fe/sub 3/(..mu../sub 3/-NPh)/sub 2/(CO)/sub 9/ have also been prepared. A particularly uniquesting reaction here is the coupling of carbene and nitrene ligands observed upon thermolysis of Fe/sub 3/(..mu..-NPh)/sub 2/(CO)/sub 8/(C(OEt)Ph) to yield free imine. A number of binuclear formyl and acyl complexes have been studied, including examples on OsW, FeMn, and IrW frameworks. One of the important conclusions from this work is that ..mu..-acyl ligands are quite unreactive and do not readily undergo transformations characteristic of terminal acyl ligands. During these studies we have also found a unique catalytic system for homogeneous reduction of CO using a combination of Ru/sub 3/(CO)/sub 12/ with CuI.

• Research Organization: Pennsylvania State Univ., University Park (USA). Dept. of Chemistry
• DOE Contract Number: AC02-79ER10345
• OSTI ID: 6766371
• Report Number(s): DOE/ER/10345-3; ON: DE85001388
• 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
COMPLEXES
KETENES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OSMIUM COMPLEXES
OXIDES
OXYGEN COMPOUNDS
REDUCTION
RESEARCH PROGRAMS
RUTHENIUM COMPLEXES
TRANSITION ELEMENT COMPLEXES