Design, DFT, experimental, and NLO studies of a new hybrid containing 1,3,4-oxadiazole and indole moieties

Abstract In this article, design and nonlinear optical (NLO) response studies of a new synthesized hybrid molecule (HM 6 ) containing 1, 3, 4-oxadiazole and indole moieties are introduced. The spatial structure of the target hybrid is analytically determined using 1 HNMR, 13 CNMR, FT-IR, UV–vis., and Mass spectra. Efficiency of the fully optimized geometry of the synthesized HM ( 6 ) is elucidated via energy gap (E HOMO -E LUMO ), potential ionization, and electron affinity. The small energy gap leads to efficient NLO response. The cooperation of 1, 3, 4-oxadiazol moiety as a good acceptor and indole as a good donor in the HM ( 6 ) enhances long π -conjugation system, led to large hyperpolarizability ( β = 2.79 × 10 −28 esu). Density functional theory and TD-DFT-assisted calculations proved high potential intramolecular charge transfer and effective β value verify NLO activities. The NLO activities of the HM ( 6 ) are examined under the excitation with 473 nm, single transverse, low power laser beam via diffraction patterns (DPs), and Z-scan techniques. As high as 5.49 × 10 −11 m 2 /W of nonlinear refractive index due to the DPs technique has been obtained. Both the nonlinear refractive index and nonlinear absorption coefficient are estimated via the standard Z-scan methods. The all-optical switching, both static and dynamic, prove to occur in the HM ( 6 ) using two visible laser beams.