Intramolecular catalysis of olefin exchange in trans-dichloro(η-olefin)(pyridine)platinum(II) complexes by the hydroxy-group of a side chain in the 2-position of the pyridine ligand

Abstract

Whereas olefin exchange in trans-dichloro(η-olefin)(pyridine)platinum(II) complexes is hindered by the presence of 2,6-substituents on the pyridine ligand, a hydroxy-group, either primary or secondary, borne by a side chain in the 2-position of this ligand can give an intramolecular catalysis of the olefin exchange reaction. This catalysis leads to a reaction that is first order in the complex and zero order in the olefin. The catalysis is dependent on the length of the side chain bearing the hydroxy-group. Kinetic data, for the substitution of 3,3-dimethylbut-1-ene by styrene, suggest that the catalysis is due to the transient formation of a (hydroxyalkylpyridine-O,N)platinum chelate.