Electrophilic addition vs electron transfer for the interaction of Ag{sup +} with molybdenum(II) hydrides. 1: Reaction with CpMoH(PMe{sub 3}){sub 3} and the mechanism of decomposition of [CpMoH(PMe{sub 3}){sub 3}]{sup +}
- Univ. of Maryland, College Park, MD (United States). Dept. of Chemistry and Biochemistry
- Univ. de Bourgogne, Dijon (France)
The compound CpMoH(PMe{sub 3}){sub 3}, 1, is oxidized by Ag{sup +} in acetonitrile to the 17-electron complex [CpMoH(PMe{sub 3}){sub 3}]{sup +}, [1]{sup +}, which is indefinitely stable at low temperature. The oxidation takes place without the observation of a silver adduct intermediate. Complex [1]{sup +} has also been generated by ferrocenium oxidation or by anodic oxidation and characterized by EPR spectroscopy. Complex [1]{sup +} slowly decomposes at room temperature by a second-order rate law ({nu} = k{sub disp}[1{sup +}]{sup 2}), consistent with a disproportionation mechanism. In the presence of unoxidized 1, on the other hand, the decomposition of [1]{sup +} is faster and proceeds via a deprotonation mechanism ({nu} = k{sub deprot}[1{sup +}][1]) with compound 1 acting as a catalyst. The ratio of the two second-order rate constants is k{sub deprot}/k{sub disp} = 5.8(7). Intermediates of the disproportionation pathway, the solvent-stabilized double-oxidation products [CpMoH(S)(PMe{sub 3}){sub 3}]{sup 2+} (S = THF, MeCN), have been isolated as stable salts with the PF{sub 6}{sup {minus}} and BF{sub 4}{sup {minus}} counterions, respectively. The acetonitrile adduct has also been characterized by X-ray crystallography. The complex [CpMoH(MeCN)(PMe{sub 3}){sub 3}]{sup 2+} slowly transfers a proton to complex 1 to afford a 1:1 mixture of [CpMo(PMe{sub 3}){sub 3}(MeCN)]{sup +} and [CpMo(PMe{sub 3}){sub 3}H{sub 2}]{sup +} and is also slowly deprotonated by NEt{sub 3}.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- OSTI ID:
- 315989
- Journal Information:
- Organometallics, Journal Name: Organometallics Journal Issue: 26 Vol. 17; ISSN ORGND7; ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
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