Syntheses And Characterization Of Blue Emitting Zinc Complexes With1,3,4-Oxadiazol-Modified Benzamides As Ligands

In order to develop highly blue luminescent metal complexes, in this paper, three series of new ligands with synergistic coordinated oxygen and nitrogen atoms were synthesized,(the structures of the ligands are described as follow) Considering the advantages of oxadiazole-functionlized benzamide ligands which containing synergistic coordinated nitrogen, oxygen atoms and large delocalized conjugated system, three series of new oxadiazole-functionlized benzamide derivtives L1-L8、P1-P8、 M1-M8and their complexes were synthesized and characterized by UV-Vis, IR, H NMR. The photophysical propertis of those zinc cpmplexes Zn-(Lx)2-H2ON Zn-(Px)2-H2O、Zn-(Mx)2-H2O (x=1～8) were thoroughly investigared.The results show that:(1) This new type of ligands and their complexes have high optical absorption coefficients(≥1.0×104). (2) These ligands have very weak fluorescence under room temperature. Upon coordination with zinc(Ⅱ) ion, the complexes exhibit efficient zinc ions perturbation deep blue emissions owing the increased rigidity of the ligands, which apparently weaken the non-radiation pathway.(3) These kind of complexes exhibited intense blue fluorescence with the emission peaks from400-436nm, with emission intensities decrease in the order of Z-(Pi-P8)> Z-(Li-L8)> Z-(M1-M8). The above results illustrated that the methoxyl group at the para-position of benzamide moieties contribute to a relative large extent for the increased fluorescence of the Zn-(Px)2-H2O complexes, which may have potential use as OLED materials.