Sb. Cao et al., MECHANISM OF CHELATION OF PHENANTHROLINE DERIVATIVES TO MO(CO)(5) DEDUCED FROM PULSED PHOTOLYSIS STUDIES IN SEVERAL SOLVENTS AT HIGH-PRESSURE, Journal of the Chemical Society. Dalton transactions, (8), 1996, pp. 1629-1635
A laser flash-photolysis kinetic study has been carried out an the con
centration, temperature and pressure dependence of chelation reactions
of the type [Mo(CO)(5)(L-L)] --> [Mo(CO)(4)(L-L)] + CO, where L-L rep
resents 1,10-phenanthroline (phen) and a series of substituted phen li
gands in several solvents. The activation parameters for these thermal
ring-closure reactions are sensitive to the nature of the solvent, as
well as to electronic and steric effects arising from the phen ligand
. All the observed kinetic effects can be accounted for by an intercha
nge ligand-substitution mechanism during which CO is displaced by the
chelate.