“…Transition metal complexes with 2,2′:6′,2′′-terpyridines and their structural analogues have recently received extensive attention due to their thermal stability, kinetic inertness, rich optical and electrochemical properties relevant for their potential applications as effective luminescent materials and promising anticancer agents [ 24 , 25 , 26 , 27 , 28 , 29 ]. The photoluminescence and biological features of these systems are generally fine-tuned by two approaches: (i) incorporation of appropriate substituents in the 4′-position of the central pyridine ring of 2,2′:6′,2′′-terpyridine [ 30 , 31 , 32 ], and (ii) substitution of peripheral pyridine rings of 2,2′:6′,2′′-terpyridine by other heterocycles [ 33 , 34 , 35 ]. Most importantly, the employment of a newly designed ligand translates to novel excited-state and physical properties of resulting transition metal complexes, and in consequence, new application potential in biology and optoelectronics.…”