Thermodynamic studies of the binding of bidentate nitrogen donors with methyltrioxorhenium (MTO) in CHCl3 solution

Abstract

Methyltrioxorhenium (MTO) adduct formation with bidentate nitrogen donors 2,2′-bipyridine (bpy), 4,4′-dimethyl-2,2′-bipyridine (Me₂bpy), 4,4′-di-tert-butyl-2,2′-bipyridine (^tBu₂bpy), 1,10-phenanthroline (phen), 5-methyl-1,10-phenanthroline (5-Mephen), 5-chloro-1,10-phenanthroline (5-Clphen), 4,7-dimethyl-1,10-phenanthroline (Me₂phen) has been studied at different temperatures in CHCl₃ solution. Spectrophotometeric measurements have been carried out to obtain the thermodynamic parameters. All complexes are enthalpy stabilized whereas the entropy changes counteract the adduct formation. The results are discussed in terms of different basicities of the bidentate N-donors.