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

Journal Article · Wed Feb 06 00:00:00 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), Vol. 107:3
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BUTENES
ISOMERIZATION
CARBON MONOXIDE
CHEMISORPTION
CATALYSTS
CHEMICAL PREPARATION
ETHYLENE
POLYMERIZATION
HYDROGENATION
PROPYLENE
THORIUM COMPLEXES
CATALYTIC EFFECTS
STRUCTURAL CHEMICAL ANALYSIS
URANIUM COMPLEXES
ALUMINIUM OXIDES
BENCH-SCALE EXPERIMENTS
CATALYST SUPPORTS
CHEMICAL ACTIVATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CYCLOALKENES
DERIVATIZATION
DIENES
EXPERIMENTAL DATA
HYDRIDES
LIGANDS
LOW TEMPERATURE
MASS SPECTROSCOPY
METHANE
MONITORING
NMR SPECTRA
ORGANOMETALLIC COMPOUNDS
PARAMETRIC ANALYSIS
REACTION INTERMEDIATES
REAGENTS
SILICA GEL
STOICHIOMETRY
ACTINIDE COMPLEXES
ADSORBENTS
ALKANES
ALKENES
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYENES
REACTION KINETICS
SEPARATION PROCESSES
SORPTION
SPECTRA
SPECTROSCOPY
SYNTHESIS
YIELDS
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)