Reaction Kinetics of the Intermediate Produced in the Laser Pulse Photolysis of Tungsten Hexacarbonyl in Fluid Solution.
Abstract
Laser pulse photolysis at 353 nm of tungsten hexacarbonyl in room temperature methylcyclohexane produces an intermediate, proposed to be W(CO)5S, S denoting solvent, with an absorption maximum at 425 nm and epsilon max. = 7,500 m to the -1 power cm. In the presence of added L = 4-acetylpyridine, the intermediate reacts completely to form W(CO)5L as final product. The rate of disappearance of the intermediate is pseudo first order, with kapp linear in (L) at low concentration but approaching a limiting value at higher concentrations. The proposed mechanism is one of reversible dissociation of W(CO)5S to W(CO)5 and S with rate constants k sub 1 and K sub -1 followed by scavenging of the W(CO)5 by the L, with rate constant k sub 2. At 20 C k sub 1 = 1,900,000 s to the -1 power and the corresponding activation quantities are E sub 1* = 3.9 kcal mole and (* sub 1 - E sub 2* = 2.6 kcal mole. The nature of the primary photolysis step is discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 05, 1981
- Accession Number
- ADA096186
Entities
People
- Alistair J. Lees
- Arthur W. Adamson
Organizations
- University of Southern California