Telechelic poly(ε-caprolactones) with tethered mixed ligand ruthenium(II) chromophores

Well-characterized templates of polymer-forming ligands and their ruthenium tris(alpha,alpha'-diimine) initiators were utilized to divergently ring open an epsilon-caprolactone monomer. The same polymers were also obtained through the synthesis of quinoline and bipyridine diimine ligands incorporating poly(epsilon-caprolactone) (PCL) chains. These polymers contain vacant molecular recognition sites, enabling subsequent chelation of these macroligands to metal precursors. Both methods provided telechelic (epsilon-caprolactone) ruthenium(II)-centered polyesters of various hierarchy. Solution properties and thermal behaviour of such polyesters are described.