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 04:00:00 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, Journal Name: Organometallics Journal Issue: 7 Vol. 11; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

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