ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, vol.56, no.3, pp.281-286, 2001 (SCI-Expanded)
The kinetics of the thermal substitution of norbornadiene (nbd) by 2,2 ' -bipyridine (2,2 ' bipy) in (CO)(4)Mo(C7H9) was studied by quantitative FT-IR and UV-VIS spectroscopy. The reaction rate exhibits first-order dependence on the concentration of the starting complex, and the observed rate constant depends on the concentration of both leaving nbd and entering 2,2 ' -bipy ligand. The mechanism was found to be consistent with the previously proposed one, where the rate determining step is the cleavage of one of the two Mo-olefin bonds. The reaction was performed at four different temperatures (35 - 50 degreesC) and the evaluation of the kinetic data gives the activation parameters which now support an associative mechanism in the transition states.