Synthesis and Substitution Kinetics of Tricarbonylrhenium(I) Dendritic Complexes

Tricarbonylrhenium(I) metallodendrimers functionalized with N, N-2-picolylamino chelates have been synthesized by the [2+1] approach. Methanol substitution reactions of the first-and second-generation poly(propylene amine) tetra-and octanuclear rhenium metallodendrimers by a range of monodentate nucleophiles (i.e. 4-dimethylaminopyridine, pyridine, and bromide ions) were investigated and compared to the substitution reactions of an analogous monomeric complex, fac-[Re(CO)(3)(N, N-bidentate)(CH3OH)]+. These detailed kinetic studies reveal that a greater activation is achieved using the metallodendrimers with no direct interactions between the metal centers.