Abstract
Irradiation (λ > 380 nm) of CpW(CO)3Me in inert solvents in the presence of PPh3 gives [PPh3CH3 +][CpW(CO)3 -] as well as the substitution product CpW(CO)2(PPh3)Me (φdisappearance CpW(CO)3Me = 0-45 ± 0.005, φappearance CpW(CO)3- = 0.04 ± 0.01). The mechanism of CpW(CO)3 - formation was studied. Experiments suggest that CpW(CO)2(PPh3)Me may be an intermediate in the reaction but direct reductive elimination of PPh3Me+ from this species or from CpW(CO)(PPh3)2Me was ruled out. Experiments using PTol3 demonstrated that PAr3Me+ (Ar = aryl) is formed from exogenous, not coordinated, phosphine. The mechanism proposed for the reduction of CpW(CO)3Me involves the intermediate formation of phosphoranyl radicals, -PPh3Me, formed by addition of Me radicals (from W-CH3 homolysis) to PPh3. Phosphoranyl reduction of a variety of metal species which are present in solution is shown to lead to CpW(CO)3 -. The proposed mechanism is isolobal with a mechanism we proposed for the photochemical disproportionation of metal-metal bonded dimers (e.g., Cp2Mo2(CO)6) involving 19-valence-electron intermediates.
| Original language | English |
|---|---|
| Pages (from-to) | 89-94 |
| Number of pages | 6 |
| Journal | Journal of the American Chemical Society |
| Volume | 108 |
| Issue number | 1 |
| Publication status | Published - 1986 |
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Cite this
Photochemical reduction of CpW(CO)3CH3 (Cp = η5-C5H5) to CpW(CO)3 -; An isolobal analogy to the disproportionation of Cp2Mo2(CO)6 . / Goldman, Alan S; Tyler, David R.
In: Journal of the American Chemical Society, Vol. 108, No. 1, 1986, p. 89-94.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Photochemical reduction of CpW(CO)3CH3 (Cp = η5-C5H5) to CpW(CO)3 -; An isolobal analogy to the disproportionation of Cp2Mo2(CO)6
AU - Goldman, Alan S
AU - Tyler, David R.
PY - 1986
Y1 - 1986
N2 - Irradiation (λ > 380 nm) of CpW(CO)3Me in inert solvents in the presence of PPh3 gives [PPh3CH3 +][CpW(CO)3 -] as well as the substitution product CpW(CO)2(PPh3)Me (φdisappearance CpW(CO)3Me = 0-45 ± 0.005, φappearance CpW(CO)3- = 0.04 ± 0.01). The mechanism of CpW(CO)3 - formation was studied. Experiments suggest that CpW(CO)2(PPh3)Me may be an intermediate in the reaction but direct reductive elimination of PPh3Me+ from this species or from CpW(CO)(PPh3)2Me was ruled out. Experiments using PTol3 demonstrated that PAr3Me+ (Ar = aryl) is formed from exogenous, not coordinated, phosphine. The mechanism proposed for the reduction of CpW(CO)3Me involves the intermediate formation of phosphoranyl radicals, -PPh3Me, formed by addition of Me radicals (from W-CH3 homolysis) to PPh3. Phosphoranyl reduction of a variety of metal species which are present in solution is shown to lead to CpW(CO)3 -. The proposed mechanism is isolobal with a mechanism we proposed for the photochemical disproportionation of metal-metal bonded dimers (e.g., Cp2Mo2(CO)6) involving 19-valence-electron intermediates.
AB - Irradiation (λ > 380 nm) of CpW(CO)3Me in inert solvents in the presence of PPh3 gives [PPh3CH3 +][CpW(CO)3 -] as well as the substitution product CpW(CO)2(PPh3)Me (φdisappearance CpW(CO)3Me = 0-45 ± 0.005, φappearance CpW(CO)3- = 0.04 ± 0.01). The mechanism of CpW(CO)3 - formation was studied. Experiments suggest that CpW(CO)2(PPh3)Me may be an intermediate in the reaction but direct reductive elimination of PPh3Me+ from this species or from CpW(CO)(PPh3)2Me was ruled out. Experiments using PTol3 demonstrated that PAr3Me+ (Ar = aryl) is formed from exogenous, not coordinated, phosphine. The mechanism proposed for the reduction of CpW(CO)3Me involves the intermediate formation of phosphoranyl radicals, -PPh3Me, formed by addition of Me radicals (from W-CH3 homolysis) to PPh3. Phosphoranyl reduction of a variety of metal species which are present in solution is shown to lead to CpW(CO)3 -. The proposed mechanism is isolobal with a mechanism we proposed for the photochemical disproportionation of metal-metal bonded dimers (e.g., Cp2Mo2(CO)6) involving 19-valence-electron intermediates.
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M3 - Article
AN - SCOPUS:0009691004
VL - 108
SP - 89
EP - 94
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 1
ER -