Polypyridine ligands with extended pi-conjugation:highly tunable fluorophores

摘要

This account is intended to give a brief overview on the potential of pi-conjugated oligomers incorporating polypyridine ligand subunits in the molecular skeleton.The case of 2,2'-bipyridine(bpy),1,10-phenanthroline(phen)and the terdentate 2,2':6'2"-terpyridine(tpy)as coordinating building-blocks is emphasized.These structures display intense visible absorption and fluorescence emission properties in solution that can be actively modulated by addition of exogenous species,such as protons or metal ions.The mechanisms underlying the photophysical changes upon protonation or metal complexation are described.Such tunable fluorophores are of tremendous interest in supramolecular chemistry and molecular materials science.