Transition metal alkyl chemistry at elevated carbon monoxide pressures. An infrared spectroscopic study of systems related to catalytic intermediates in homogeneous hydroformylation reactions

Journal Article · Wed Mar 15 00:00:00 EST 1978 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00474a008· OSTI ID:6786861

King, R B; King, Jr, A D; Iqbal, M Z; Frazier, C C

Reactions of transition metal alkyls with CO at elevated pressures (approximately 300 atm) in n-tetradecane solution have been followed by infrared spectroscopy under pressure using the ..nu..(CO) region to identify carbonyl intermediates. The Mn carbonyl derivative CH/sub 3/Mn(CO)/sub 5/ reacts with CO to give CH/sub 3/COMn(CO)/sub 5/ which in turn reacts with H/sub 2/ to give Mn/sub 2/(CO)/sub 10/ and CH/sub 3/CHO. However, the substituted Mn carbonyl derivatives cis-CH/sub 3/Mn(CO)/sub 4/PR/sub 3/ (R = C/sub 6/H/sub 5/, OC/sub 6/H/sub 5/, and N(CH/sub 3/)/sub 2/) react with CO to give mixtures of CH/sub 3/COMn(CO)/sub 5/, CH/sub 3/COMn(CO)/sub 4/PR/sub 3/, and PR/sub 3/ which form no CH/sub 3/CHO upon treatment with H/sub 2/. The Re carbonyl derivative CH/sub 3/Re(CO)/sub 5/ forms Re/sub 2/(CO)/sub 10/ rather than CH/sub 3/CORe(CO)/sub 5/ upon heating with CO under pressure. The cyclopentadienyliron derivative CH/sub 3/Fe(CO)/sub 2/C/sub 5/H/sub 5/ undergoes carbonylation to give CH/sub 3/COFe(CO)/sub 2/C/sub 5/H/sub 5/, but hydrogenolysis of this acyl produces no CH/sub 3/CHO. The alkyls RM(CO)/sub 3/C/sub 5/H/sub 5/ (M = Mo, R = CH/sub 3/, C/sub 2/H/sub 5/, CH/sub 2/ = CHCH/sub 2/, C/sub 6/H/sub 5/CH/sub 2/, and CH/sub 3/SCH/sub 2/; M = W, R = CH/sub 3/) react with CO under pressure to form M(CO)/sub 6/ without any evidence for the formation of the corresponding acyl derivatives RCOM(CO)/sub 3/C/sub 5/H/sub 5/. In the case of CH/sub 3/Mo-(CO)/sub 3/C/sub 5/(CH/sub 3/)/sub 5/ the substituted cyclopentadienyl ring is liberated as the ketone CH/sub 3/COC/sub 5/(CH/sub 3/)/sub 5/ upon carbonylation. These results show that the presence of strong metal-alkyl bonds or easily displaced ligands prevent the carbonylation of alkyl-metal derivatives to the corresponding acyl-metal derivatives and the presence of weaker ..pi.. acceptors than CO such as trivalent P or eta/sup 5/-cyclopentadienyl ligands prevent the hydrogenolysis of acyl-metal derivatives to the corresponding aldehydes. These results provide some information on the types of transition metal systems likely to be the best candidates for hydroformylation catalysts. Details of an apparatus for obtaining infrared spectra at elevated pressures up to 500 atm are described.

• Research Organization: Univ. of Georgia, Athens
• OSTI ID: 6786861
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 100:6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALDEHYDES
CHEMICAL REACTION YIELD
CARBONYLATION
CATALYSIS
IRON COMPLEXES
CATALYTIC EFFECTS
KETONES
MANGANESE COMPLEXES
MOLYBDENUM COMPLEXES
RHENIUM COMPLEXES
TUNGSTEN COMPLEXES
CARBON MONOXIDE
CARBONYLS
CHEMICAL REACTIONS
INFRARED SPECTRA
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
COMPLEXES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SPECTRA
TRANSITION ELEMENT COMPLEXES
YIELDS
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)
400201 - Chemical & Physicochemical Properties