Hydrocarbon activation by gas-phase lanthanide cations: interaction of Pr/sup +/, Eu/sup +/, and Gd/sup +/ with small alkanes, cycloalkanes, and alkenes

Journal Article · Wed Jan 06 04:00:00 EST 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00209a002· OSTI ID:7247330

Schilling, J B; Beauchamp, J L

The authors describe ion beam studies of the interaction of gas-phase lanthanide ions, praseodymium (Pr/sup +/), europium (Eu/sup +/), and gadolinium (Gd/sup +/), with small alkanes, cycloalkanes, alkenes, and several oxygen-containing compounds. Only Gd/sup +/ is seen to activate C-H and C-C bonds of alkanes. The ground state electronic configuration of Gd/sup +/ (4f/sup 7/5d/sup 1/6s/sup 1/) is different from those of Pr/sup +/ (4f/sup 3/6s/sup 1/) and Eu/sup +/ (4f/sup 7/6s/sup 1/), leading to the conclusion that the f electrons play little part in the metal ion reactivity. Gd/sup +/ can be thought of as having two valence electrons, and indeed it reacts similarly to Sc/sup +/ and the other group 3 metal ions Y/sup +/ and La/sup +/, yielding products corresponding to elimination of hydrogen, alkanes, and alkenes. The elimination of neutral alkenes in the reaction of Gd/sup +/ with alkanes results in the formation of metal dialkyl or hydrido-alkyl complexes. This finding leads to estimates for the sum of two Gd/sup +/ sigma bond dissociation energies of between 110 and 130 kcal/mol. Gd/sup +/ and Pr/sup +/ react readily with alkenes, yielding mostly dehydrogenation products along with smaller amounts of C-C bond cleavage products. Reactions of Gd/sup +/ and Pr/sup +/ with oxygen-containing species such as nitric oxide, formaldehyde, acetaldehyde, and acetone yield primarily the metal oxide ions and provide a lower limit for D(M/sup +/-O) of 179 kcal/mol, in good agreement with literature values of D(Pr/sup +/-O) = 188.4 +/- 5.2 kcal/mol and D(Gd/sup +/-0) = 181.0 +/- 4.4 kcal/mol. In keeping with the strong metal sigma bonds, Gd/sup +/ is also seen to readily react with formaldehyde to eliminate CO and form GdH/sub 2//sup +/.

• Research Organization: California Institute of Technology, Pasadena (USA)
• OSTI ID: 7247330
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:1; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
640304 -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
ALKENES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COLLISIONS
CYCLOALKANES
DATA
DISSOCIATION ENERGY
ELECTRONIC STRUCTURE
ENERGY
EUROPIUM COMPOUNDS
EXPERIMENTAL DATA
FLUIDS
GADOLINIUM COMPOUNDS
GASES
HYDROCARBONS
INFORMATION
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONS
MOLECULE COLLISIONS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
RARE EARTH COMPOUNDS
VALENCE
YIELDS