Synthesis and Linear and Nonlinear Optical Properties of Three Push–Pull Oxazol-5(4H)-one Compounds

Abstract

Three uncharged push-pull oxazol-5(4H)-ones were synthesized and thoroughly characterized. The examined molecules contained electron-donor and electron-acceptor groups interacting via a π-conjugated bridge. Spectral properties of the oxazol-5(4H)-ones were studied in detail in three solvents of different polarities. The results indicate a solvatochromic shift toward lower energy for the charge-transfer state. The compounds are weakly fluorescent in polar solvents, but they have high fluorescence quantum yields in nonpolar solvents. Their two-photon absorption (2PA) properties were characterized by the open- and closed-aperture Z-scan technique, by the pump-probe technique, and by the two-photon excited fluorescence method. The dyes exhibit relatively high effective two-photon absorption cross sections ranging from 490 to 2600 GM at ~100 GW/cm(2), according to the Z-scan results, which are found, however, to contain significant contribution from higher-order absorption processes. In addition, these compounds display good photostability.

Solvent dependent linear and nonlinear optical properties of triphenylamine unit incorporated difluoroboron β-diketonate complexes

“…The peak-valley configuration indicates the prominent self-defocusing effect of light in the four studied fluorophores [84]. In the CA Z-scan measurements, usually there will be an influence of nonlinear absorption [85,86]. The nonlinear absorption will give rise to a distortion of the shape of the theoretical curve in the CA Z-scan by increasing the peak or valley [87].…”

Structural effect of oxazolone derivatives on the initiating abilities of dye-borate photoredox systems in radical polymerization under visible light

“…However, the main absorption peak of 3 is slightly blue shied. As described earlier, 47,53 this trend is connected with an elongation of the p system which results in a decrease of the effectiveness of charge transfer between the electron donor (triphenylamine) and the electron acceptor (2-phenyloxazolone) moieties caused by the internal rotation.…”

“…0.095) indicating that the nonradiative pathways are reduced in such structures. 47,53 The photochemical reactivity of new photoinitiating systems was investigated by steady state photolysis experiments upon DPSS laser exposure in ethyl acetate as described previously. 47,53 The maximum of their absorption is not sensitive to the irradiation, there are no signicant changes in band position and its intensity upon 473 nm irradiation.…”

“…47,53 The photochemical reactivity of new photoinitiating systems was investigated by steady state photolysis experiments upon DPSS laser exposure in ethyl acetate as described previously. 47,53 The maximum of their absorption is not sensitive to the irradiation, there are no signicant changes in band position and its intensity upon 473 nm irradiation. On the other hand, for oxazolone derivatives/borate solution, the absorption bands intensity strongly decreases upon the irradiation, as resulting from the photosensitized decomposition of the dyes (Fig.…”

NLO‐Phoric Emissive Quinoxaline Analog of Quinoline Yellow 54 and Z‐Scan Studies

“…The third‐order nonlinear susceptibility χ (3) is determined by β and n 2 . The closed aperture Z‐scan values provide the nonlinear refractive index(n 2 ), whereas the nonlinear absorption coefficient (β) is estimated from open aperture Z‐scan measurements ,…”