Synthesis and nonlinear optical characterization of new 1,3,4-oxadiazoles

A new series of 1,3,4-oxadiazole derivatives containing 2-fluoro-4-methoxy phenyl were synthesized by refluxing mixture of acid hydrazide 3 with different aromatic carboxylic acids (a-e) in phosphorous oxychloride. These newly synthesized compounds were characterized by NMR, mass spectral, and IR spectral studies, and also by C, H, N analyses. The open-aperture z-scan experiment was employed to measure the optical nonlinearity of the samples at 532 nm, using 5 ns laser pulses. The measurements indicate that compound 4a, which contains Bromine, behaves as an optical limiter at this wavelength, with potential applications in optoelectronics.