Routes to metallodendrimers: synthesis of isomeric neutral metallomacromolecules based on bis(2,2':6',2"-terpyridine)ruthenium(II) connectivity

Routes for the syntheses of isomeric, zwitterionic, bisterpyridine-Ru(II)-based macromolecules are described. Access to these novel architectures is facilitated by the construction of terpyridine-modified, 1-->3 C-branched, ester-terminated building blocks. Constitutional isomers result from the interchangable placement of methyl and tert-butyl ester groups on both the branched framework near the Ru(II) centers and the termini of the branched construct. Water solubility is imparted to each isomer through selective transformation of the tert-butyl esters to their corresponding carboxylates. Along with the standard characterization techniques, electrochemical and spectroscopic data also support the structural formation.