Synthesis and photophysical properties of pyridyl conjugated triazole appended naphthalenediimide derivatives

A series of three substituted triazole appended NDI-derivatives, 2,7-bis(3,5-di(pyridin-X-yl)-4H-1,2,4-triazol-4-yl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone (where X = 2, NDI-PyTz-1; 3, NDI-PyTz-2; and 4, NDI-PyTz-3), were designed, synthesized and well characterized using various analytical and spectroscopic techniques. All the three NDI-PyTz derivatives exhibit decent electronic properties as suggested by DFT, cyclic voltammetry and fluorescence studies. In particular, NDI-PyTz-1 demonstrated the generation of a stable anion radical [NDI-PyTz-1]˙−.