Luminescence Spectral Properties of 2-[2-Methyl(Acetyl, Tosyl)oxyphenyl]-5-(3,4,5-trimethoxy-phenyl)-1,3,4-oxadiazoles

Cyclodehydration of N ′-aroylbenzohydrazides in thionyl chloride gave 2-(2-hydroxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazole and its 2-(2-methoxyphenyl) analog. Acetylation and tosylation of 2-(2-hydroxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazole afforded 2-acetoxyphenyl and 2-tosyloxy­phenyl derivatives. 2-[2-Methoxy(acetoxy, tosyloxy)phenyl]-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazoles showed strong luminescence (φ 0.22–0.99) in the blue–volet region with the emission maximum in the range λ 364–453 nm. The effect of solvent polarity on the absorption and emission spectra of these compounds was studied.