Reactions of FeCH/sub 3//sup +/ and CoCH/sub 3//sup +/ with aliphatic alkanes in the gas phase

Journal Article · Wed Jul 11 04:00:00 EDT 1984 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00326a002· OSTI ID:6363906

Jacobson, D B; Freiser, B S

The gas-phase reactions of FeCH/sub 3//sup +/ and CoCH/sub 3//sup +/ with aliphatic alkanes up to C/sub 6/H3exclamation/sub 4/ were studied. FeCH/sub 3//sup +/ is completely unreactive with the aliphatic alkanes, while CoCH/sub 3//sup +/ reacts with all alkanes larger than ethane by initial insertion into a C-H bond resulting in CH/sub 4/ loss followed by dehydrogenation or alkane elimination forming Co(allyl)/sup +/ products. The Co(allyl)/sup +/ ions react rapidly with the alkanes (except methane) predominantly by dehydrogenation generating allyl-olefin complexes. The results indicate that the cobalt-allyl bond strength, D/sup 0/(Co/sup +/-C/sub 3/H/sub 5/), is in excess of 72 kcal/mol while D/sup 0/(Co/sup +/-butadiene) appears to be less than 52 kcal/mol. CoCH/sub 3//sup +/ also abstracts a hydride from alkanes larger than ethane (except for 2,2-dimethylpropane) forming C/sub n/ H/sub 2n + 1//sup +/ and implying D/sup 0/(CoCH/sub 3/-H/sup -/) = 256 +/- 10 kcal/mol which together with an earlier reported value of ..delta..H/sub f//sup 0/ (CoCH/sub 3/) = 256 +/- 4 kcal/mol yields D/sup 0/(CoCH/sub 4/) = 49 +/- 11 kcal/mol and ..delta..H/sub f//sup 0/ (CoCH/sub 4/) = 35 +/- 11 kcal/mol. Structures of the major primary product ions were investigated both by collision-induced dissociation (CID) and by specific ion-molecule reactions. 32 references, 7 figures, 1 table.

• Research Organization: Purdue Univ., West Lafayette, IN
• DOE Contract Number: AC02-80ER10689
• OSTI ID: 6363906
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 106:14; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

2-2-DIMETHYLPROPANE
2-METHYLBUTANE
2-METHYLPROPANE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKANES
BINDING ENERGY
BUTANE
CATIONS
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT COMPLEXES
COMPARATIVE EVALUATIONS
COMPLEXES
DATA
ENERGY
EXPERIMENTAL DATA
FLUIDS
FOURIER TRANSFORM SPECTROMETERS
GASES
HEXANE
HYDROCARBONS
INFORMATION
ION CYCLOTRON RESONANCE SPECTROSCOPY
ION SPECTROSCOPY
IONS
IRON COMPLEXES
KINETICS
LIGANDS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PENTANE
PROPANE
REACTION INTERMEDIATES
REACTION KINETICS
SPECTROMETERS
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENT COMPLEXES