Novel 10,13-disubstituted dipyrido[3,2-a:2′,3′-c]phenazines and their platinum(II) complexes: highly luminescent ICT-type fluorophores based on D–A–D structures

Novel donor–acceptor–donor (D–A–D) π-conjugated molecules based on a dipyrido[3,2-a:2′,3′-c]phenazine (dppz) skeleton were synthesized, and their luminescent properties were investigated. Introduction of various aryl substituents to the 10- and 13-positions of dppz allowed us to tune the emission properties through modulation of the intramolecular charge transfer (ICT) character on the D–A–D chromophores. Coordination of platinum(II) to the diimine site of dppz also gave rise to facilitation of the ICT to induce a significant red shift of the emission.