Synthesis and luminescent properties of novel Cu (II), Zn (II) polymeric complexes based on 1,10-phenanthroline and biphenyl groups

A fully conjugated ligand 4,4′-bis(1,10-phenanthroline-[5,6-d]imidazole-2-yl)-biphenyl (BPIBP) based on 1,10-phenanthroline and biphenyl groups was firstly synthesized. The corresponding polymeric complexes, BPIBP (1) with Cu(II) (2) and Zn(II) (3), were synthesized and characterized by FT-IR, elemental Analysis, conductivity measurement. UV-Vis and fluorescence spectra at room temperature revealed that both the polymeric complexes 2 and 3 emit blue luminescence at 453 and 452 nm (λem, max) in DMSO solution and blue/green luminescence at 527 and 536 nm (λem, max) in solid state respectively, and the maximum wavelengths of the polymeric complexes 2 and 3 are red shifted, compared with the ligand 1. Thermal property measurements show that they have good thermal stability.