Lewis-acid-promoted decarbonylation of coordinated carbon dioxide: Reactions of ({eta}{sup 5}-MeC{sub 5}H{sub 4}){sub 2}Nb({eta}{sup 2}-CO{sub 2})CH{sub 2}SiMe{sub 3} with Lewis acids

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · Organometallics

OSTI ID:567345

Fu, Peng-fei; Khan, M A; Nicholas, K M ^[1]

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1. Univ. of Oklahoma, Norman, OK (United States)

The interaction of Cp{prime}{sub 2}Nb({eta}{sup 2}-CO{sub 2})CH{sub 2}SiMe{sub 3} (1; Cp{prime} = {eta}{sup 5}-MeC{sub 5}H{sub 4}) with several Lewis acids has been studied and found to result in facile decarbonylation of 1; the Nb-containing products depend markedly on the Lewis acid partner. Reaction of 1 with LiPF{sub 6} or BF{sub 3}{center_dot}Et{sub 2}O causes both decarbonylation and deoxygenation, producing [Cp{prime}{sub 2}Nb(F)CH{sub 2}SiMe{sub 3}]Z [Z = PF{sub 6}{sup -}(3), BF{sub 4}{sup -} (6)], which have been characterized spectroscopically and (for 3) by X-ray diffraction; 3 is also produced in the reaction of the oxo derivative Cp{prime}{sub 2}Nb(O)CH{sub 2}SiMe{sub 3} (2) with LiPF{sub 6} or BF{sub 3}{center_dot}Et{sub 2}O. 1 reacts with ZnCl{sub 2} first to form an adduct, Cp{prime}{sub 2}Nb-(CO){sub 2}CH{sub 2}SiMe{sub 3}{center_dot}ZnCl{sub 2} (7), which based on IR and NMR data appears to have a novel {mu}-CO{sub 2} unit bridging Nb and Zn. Complex 7 is unstable, decomposing with CO loss to form [Cp{prime}{sub 2} Nb(CH{sub 2}SiMe{sub 3})O{center_dot}ZnCl{sub 2}]{sub 2} (8), an adduct of ZnCl{sub 2} with the oxo species 2, which has been characterized crystallographically; 8 is also produced from 2 and ZnCl{sub 2}. Reaction of 1 with HgCl{sub 2} rapidly produces an incompletely characterized product 10, which has been both decarbonylated and dealkylated. Although CdCl{sub 2} does not react with 1 under comparable conditions, Me{sub 3}SiCl reacts rapidly with 1 to produce Cp{prime}{sub 2}Nb(O) Cl (11), resulting from decarbonylation and dealkylation; the structure of 11 has been established by X-ray diffraction. 19 refs., 3 figs., 5 tabs.

• OSTI ID: 567345
• Journal Information: Organometallics, Vol. 11, Issue 7; Other Information: PBD: Jul 1992
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
36 MATERIALS SCIENCE
CARBON DIOXIDE
DEALKYLATION
DECARBONIZATION
MOLECULAR STRUCTURE
STRUCTURAL CHEMICAL ANALYSIS
ACTIVATION ENERGY
CHEMICAL ACTIVATION
COMPLEXES
CRYSTAL STRUCTURE
CHEMICAL REACTIONS
CHEMICAL REACTION KINETICS
ADDUCTS
SYNTHESIS
CARBONYLS
LEWIS ACIDS
X-RAY DIFFRACTION
CHEMICAL BONDS
NMR SPECTRA
INFRARED SPECTRA
TRANSITION ELEMENTS
ELECTROCHEMISTRY
ORGANOMETALLIC COMPOUNDS