Carbon monoxide activation by organoactinides: a comparative synthetic, thermodynamic, kinetic, and mechanistic investigation of migratory CO insertion into actinide-carbon and actinide-hydrogen bonds to yield eta/sup 2/-acyls and eta/sup 2/-formyls

Journal Article · Wed Nov 14 00:00:00 EST 1984 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00335a031· OSTI ID:5959965

Moloy, K G; Marks, T J

Reported are results of the synthesis, characterization, and carbon monoxide chemistry of a series of sterically hindered thorium alkyls and hydrides of the type Cp'/sub 2/ Th(R)(X) (Cp' = eta/sup 5/-C/sub 5/Me/sub 5/) where R = H, D, methyl, eta-butyl, and CH /sub 2/-t-Bu and X = OCH-t-Bu/sub 2/, OC/sub 6/H/sub 3/-2,6-t-Bu/sub 2/, and O-t-Bu. In addition, improved syntheses of the known complexes (Cp'/sub 2/Th(..mu..-H)(H))/sub 2/, Cp'/sub 2/Th(O-t-Bu)(Cl) and Cp'/sub 2/Th(CH/sub 2/-t-Bu)(Cl) are presented. The alkyl complexes undergo facile, irreversible carbonylation to yield eta/sup 2/-acyls that were characterized by a variety of methods. Infrared Ir and /sup 13/C NMR spectra of these complexes demonstrate that strong meta-(acyl)oxygen bonding takes place, fostering a pronounced carbene-like character. Thus, these complexes are characterized by low C-O Ir infrared stretching frequencies (nu/sub CO/ = 1450-1480 cm/sup -1/) and low-field /sup 13/C NMR chemical shifts (delta/sub /sup 13/C/ 355-370). The hydrides undergo a rapid, reversible, migratory CO insertion to yield formyls that have been characterized spectroscopically at low temperature. Infrared Ir and /sup 13/C NMR spectra of these species are similar to the corresponding acyls, suggesting an analogous eta/sup 2/ structure. Variable-temperature equilibrium data show that the insertion of CO into thorium-hydrogen bonds is exothermic by ca. 5 kcal/mol, and this value is compared to that for the analogous alkyls. The equilibrium was also found to exhibit a distinct equilibrium isotope effect upon deuterium substitution, K/sub H//K/sub D/ = 0.31 at -78/sup 0/C. The carbonylation of the complex Cp'/sub 2/Th(n-Bu)(OCH-t-Bu/sub 2/) was found to obey a second-order rate law where rate = kP/sub CO/ (complex). The insertion of CO into the Th-H bond of Cp'/sub 2/Th(H)(OCH-t-Bu/sub 2/) was found by NMR methods to be first order in metal hydride. 55 references, 3 figures, 6 tables.

• Research Organization: Northwestern Univ., Evanston, IL
• OSTI ID: 5959965
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 106:23
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
CARBON MONOXIDE
CHEMICAL ACTIVATION
THORIUM COMPLEXES
CARBONYLATION
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
ABSORPTION SPECTROSCOPY
ALCOHOLS
ALKANES
CHEMICAL REACTION KINETICS
COMPARATIVE EVALUATIONS
CORRELATIONS
CYCLOALKENES
DATA ANALYSIS
DEUTERIDES
DIENES
EXPERIMENTAL DATA
INFRARED SPECTRA
LIGANDS
MATHEMATICAL MODELS
NMR SPECTRA
ORGANOMETALLIC COMPOUNDS
THERMODYNAMICS
THORIUM CHLORIDES
THORIUM HYDRIDES
ACTINIDE COMPLEXES
ACTINIDE COMPOUNDS
ALKENES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COMPLEXES
DATA
DEUTERIUM COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYENES
REACTION KINETICS
SPECTRA
SPECTROSCOPY
THORIUM COMPOUNDS
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials