Supported organoactinides. Surface chemistry and catalytic properties of alumina-bound (Cyclopentadienyl)- and (Pentamethylcyclopentadienyl)thorium and -uranium hydrocarbyls and hydrides

Journal Article · Wed Feb 06 04:00:00 EST 1985 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00289a016· OSTI ID:5837450

He, M Y; Xiong, G; Toscano, P J; Burwell, Jr, R L; Marks, T J

Results of a detailed, quantitative investigation are reported of surface chemistry and catalysis involving selected organoactinides and partially dehydroxylated (PDA) or dehydroxylated (DA) alumina supports. For the complexes Cp'/sub 2/M(CH/sub 3/)/sub 2/ and Cp'/sub 2/M(CD/sub 3/)/sub 2/ (Cp' = eta/sup 5/ - (CH/sub 3/)/sub 5/; M = Th, U), methane-evolving surface reaction pathways are identified as M-CH/sub 3/ protonolysis via surface OH (especially on PDA), Cp' H atom abstraction, and intramolecular elimination of methane within M(CH/sub 3/)/sub 2/ units. This latter process is proposed on the basis of methylene transfer to acetone and some olefin metathesis activity to result in Al/sup 3 +/-stabilized alkylidenes. Hydogenolysis studies indicate that ca. 25% of the Cp'/sub 2/M(CH/sub 3/)/sub 2//DA surface M-CH/sub 3/ groups are removable as methane; reduction of methyl chloride to methane confirms the presence of surface M-H groups produced by hydrogenolysis. The Cp'/sub 2/M(CH/sub 3/)/sub 2//DA complexes are active catalysts for propylene hydrogenation following a variety of pretreatment conditions, with N/sub t/ approx. = 0.5 s/sup -1/ in a flow reactor at -63/sup 0/C (about 10 times more active than typical Pt/SiO/sub 2/ catalysts under the same conditions). M = Th and U are comparable in hydrogenation activity, and CO poisoning experiments indicate that ca. 3% of the adsorbed molecules are catalytically active. Cp'/sub 2/M(CH/sub 3/)/sub 2/ complexes on PDA and silica gel are considerably less active catalysts. The Cp'/sub 2/M(CH/sub 3/)/sub 2//DA systems are also active catalysts for ethylene polymerization and weakly active for butene isomerization. Experiments with Cp'/sub 2/Th(CH/sub 2/C(CH/sub 3/)/sub 3/)/sub 2/ and (Cp'/sub 2/Th(..mu..-H)H)/sub 2/ on DA reveal activity for propylene hydrogenation comparable to the Cp'/sub 2/M(CH/sub 3/)/sub 2/ systems. In contrast, more coordinatively saturated Cp/sub 3/UCH/sub 3/ and Cp/sub 3/Th(n-C/sub 4/H/sub 9/) (Cp = eta/sup 5/-C/sub 5/H/sub 5/) are far less active, while Cp'Th(CH/sub 2/C/sub 6/H/sub 5/)/sub 3/ is far more active (N/sub t/ approx. = 10 s/sup -1/).

• Research Organization: Northwestern Univ., Evanston, IL
• DOE Contract Number: AC02-81ER10980
• OSTI ID: 5837450
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 107:3; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
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400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPLEXES
ADSORBENTS
ALKANES
ALKENES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BENCH-SCALE EXPERIMENTS
BUTENES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISORPTION
COMPLEXES
CYCLOALKENES
DATA
DERIVATIZATION
DIENES
ETHYLENE
EXPERIMENTAL DATA
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGENATION
INFORMATION
ISOMERIZATION
KINETICS
LIGANDS
LOW TEMPERATURE
MASS SPECTROSCOPY
METHANE
MONITORING
NMR SPECTRA
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
POLYENES
POLYMERIZATION
PROPYLENE
REACTION INTERMEDIATES
REACTION KINETICS
REAGENTS
SEPARATION PROCESSES
SILICA GEL
SORPTION
SPECTRA
SPECTROSCOPY
STOICHIOMETRY
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
THORIUM COMPLEXES
URANIUM COMPLEXES
YIELDS