Synthesis and characterization of potential efficient electroluminescent materials: 2-Phenyl-5-[4-(4-phenylamino-2H-1,2,3-triazol-2-yl)]phenyl-1,3,4- oxadiazole derivatives

Recently, 1,3,4-oxadiazole-based on heterocyclic compounds were investigated as electroluminescent materials. In this work, we first introduce 1,2,3-triazole to synthesize a series of 1,3,4-oxadiazole-1,2,3-triazole hybrids derivatives as potential electroluminescent materials and explore the effect of modification of the 1,2,3-triazole moiety. The λ_max values of the UV-vis of 1,3,4-oxadiazole-1,2,3-triazole hybrids are promoted to longer wavelengths (340-350 nm) than the traditional 1,2,3-triazole derivatives (280-330 nm) in solutions and have a bathochromic shift to 350-360 nm in THF solution. The λ_max values of the photoluminescence (PL) spectra are in the range 406-480 nm in solutions. Compound 7h evaporated to form films on quartz substrates, had a maximum at 455 nm and showed a red-shift (≈40 nm) with respect to the solution spectrum. The solution fluorescence quantum yields (Φ_f) were measured, all of which fell into the range 0.65-0.76, and were determined relative to that of 2-phenyl-5-(4-biphenyl) -1,3,4-oxadiazole in benzene (Φ_f = 0.80). 1,3,4-Oxadiazole-1,2,3- triazole hybrids derivatives show unclearly reversible reduction processes in cyclic voltammogram measurements. Following spectroscopic studies and observation of the electrochemical behaviors, 1,3,4-oxadiazole-1,2,3-triazole derivatives were determined to be highly potential efficient blue electroluminescent materials.