Kinetics of the substitution of norbornadiene in tetracarbonyl(norbornadiene)molybdenum(0) by 2,2 '-3-bipyridine


Kayran C., Okan E.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, vol.56, no.3, pp.281-286, 2001 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 56 Issue: 3
  • Publication Date: 2001
  • Journal Name: ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.281-286
  • Keywords: 2,2 '-bipyridine, norbomadiene, molybdenum, CHELATE RING-CLOSURE, M = CR, PHOTOCATALYTIC HYDROGENATION, DISPLACEMENT KINETICS, METAL-COMPLEXES, DIENES, LIGAND, 1,5-CYCLOOCTADIENE, INTERMEDIATE, REACTIVITY
  • Middle East Technical University Affiliated: Yes

Abstract

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.