Synthesis and performances of a tridentate 8-hydroxyquinoline derivative ligand and its zinc complex

A novel N,N,O-tridentate ligand of 8-hydroxyquinoline (Q) derivative, namely 2-(benzimidazol-2-yl)-8-butoxyquinolin(BIBQ), has been synthesized with 8-hydroxyquinadine and o-diaminobenzene as the starting materials. The as-prepared ligand reacted with diethylzinc to give Zn(II) complex. The ligand and complex were then characterized by carbon nuclear magnetic resonance (13C NMR), proton nuclear magnetic resonance (1H NMR), mass spectra (MS) and elemental analysis (EA). In addition, the thermal performance, the electrochemical performance and the photoluminescence performance of zinc complex were investigated. The results showed that the decomposition temperature (onset) of the complex is 290 °C, indicating relatively higher thermal stability. Moreover, the energy levels of the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and the energy gap were calculated to be − 5.41, − 2.74 and 2.67 eV, respectively. The emission spectra of the complex in solution and solid were also studied and obviously emitted fluorescence at λmax = 493 nm.