Pressure effects on the photoreactions of the iron acyl complex ([eta][sup 5]-C[sub 5]H[sub 5])Fe(CO)[sub 2](COCH[sub 3]). Mechanistic implications regarding competitive reactions of the solvento intermediate ([eta][sup 5]-C[sub 5]H[sub 5])Fe(CO)(Sol)(COCH[sub 3])
- Universitaet Witten/Herdecke (Germany)
- Univ. of California, Santa Barbara (United States)
Photolysis of CpFe(CO)[sub 2](COCH[sub 3]) (Cp = [eta][sup 5]-C[sub 5]H[sub 5]) plus P(OCH[sub 3])[sub 3](L) in n-heptane solutions leads to the competitive decarbonylation to give CpFe(CO)[sub 2]CH[sub 3] and ligand substitution to give CpFe(CO)L(COCH[sub 3]). The application of hydrostatic pressure changes the relative quantum yields of the two processes, higher pressure strongly favoring the ligand photosubstitution pathway. These differences are interpreted in terms of the competitive reactions of the solvento intermediate CpFe(CO)(Sol)(COCH[sub 3]) (S), shown previously (J. Am. Chem. Soc. 1991, 113, 9524-9528) to be formed by the initial photolysis step, i.e., the labilization of CO. The much more negative apparent activation volume for the ligand substitution pathway suggest that this proceeds via an associative mechanism of S, while the competing methyl migration to the metal may require simultaneous dissociation of the coordinates solvent molecule, Sol. 16 refs., 1 fig.
- DOE Contract Number:
- FG03-85ER13317
- OSTI ID:
- 6567451
- Journal Information:
- Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 12:1; ISSN 0276-7333; ISSN ORGND7
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ALKANES
CARBONYLS
CHEMICAL REACTIONS
DECOMPOSITION
DISPERSIONS
HEPTANE
HYDROCARBONS
IRON COMPOUNDS
MIXTURES
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PRESSURE DEPENDENCE
SOLUTIONS
SOLVENTS
TRANSITION ELEMENT COMPOUNDS
YIELDS