An extensive investigation of structural, linear, and ultrafast third-order nonlinear optical properties of a novel trimethoxy anthracene chalcone: Experimental and DFT studies

The structural, thermal, linear, and nonlinear optical (NLO) properties of a novel chalcone derivative (2E)-1-(9-anthryl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-one (345TMANC) are presented in this study. The chalcone was synthesized using Claisen-Schmidt condensation method and single crystals were grown under a slow evaporation solution growth approach. Single-crystal XRD data confirmed that the crystal structure belongs to the monoclinic system with space group P21/n. The functional groups were confirmed by NMR and FTIR spectroscopic techniques. The optical transparency was observed in the visible region and the thermal stability of the crystal was found to be up to 174 degrees C. The intermolecular interactions of the chalcone were examined by Hirshfeld surface analysis. The Z-scan method and degenerate four-wave mixing (DFWM) methods were adopted to explore the ultrafast third-order nonlinear optical characteristics using a Ti:sapphire laser amplifier pulses (similar to 70 fs, 800 nm, 1 kHz repetition rate, maximum of similar to 4 mJ energy). Z-scan study confirms the two-photon assisted reverse saturated absorption (beta=5.05x10(-12) cm/W) and self-focusing nonlinear refraction (n(2)=1.65x10(-16) cm(2)/W). Further, optical limiting switching behaviour was observed in the sample with an onset limiting threshold value 6.65 mJ/cm(2). The decay time of 119 fs was obtained from time-resolved DFWM data. In support of the experimental results, frontier molecular energies (HOMO-LUMOs), chemical reactivity descriptors, electronic polarizability, and 2(nd) hyperpolarizabilities were calculated theoretically (DFT) with B3LYP/6-311+G(d,p) theory. The experimental results are in good agreement with the computational data and demonstrate the nonlinearity due to substituent electron donor groups in the molecule. The findings indicate that 345TMANC could be a promising candidate for use in devices such as optical switches and optical limiters.