Abstract:

Two ferrocene-based isomeric chalcone derivatives 1-ferrocenly-3-(thiophen-2-yl) prop-2-en-1-one(a) and 1-(ferrocenly)-3-(thiophen-3-yl) prop-2-en-1-one(b) were synthesized. Their third-order nonlinear optical properties were measured by Z-scan technique with ultrafast laser operating at 532 nm laser in 180 fs pulse, respectively. The relevant parameters were given as follows: the nonlinear absorption coefficient β=-2.1×10^-12 m/W, the nonlinear refractive index n₂=1.9×10^-19 m²/W and the third-order nonlinear hyperpolarizability γ=5.37×10^-32 esu for compound a; β=-1.2×10^-13 m/W, n₂=2.0×10^-19 m²/W and γ=4.48×10^-32 esu for compound b. The results indicate that the excitation of femtosecond laser enables intramolecular charge transfer to occur quickly. Thus two compounds can exhibit ultrafast third-order nonlinear optical response. The orbital energies, polarizabilities and possession ratios of different groups in frontier molecular orbitals of compounds a and b were calculated by B3LYP/6-311+G(d,p) level. The percentage of ferrocene group in the frontier molecular orbitals of compounds a and b is 97% and 98%, respectively, which indicates that ferrocene group plays a leading role in the nonlinear optical properties of two compounds.

Key words: chalcone derivatives, Z-scan technique, theoretical simulation, ultrafast third-order nonlinear optical response