Photonic properties of star shaped ferrocenyl substituted triazines

Abstract

We report the linear and nonlinear optical properties of the star shaped ferrocenyl substituted thiophene triazines 1–4. The red shift in π→π* absorption and enhancement in molar extinction coefficient (ε) in triazines 1–4 were found to be directly proportional to the conjugation length, whereas the HOMO-LUMO gap in triazines 1–4 were found to be inversely proportional to the conjugation length. The time dependent density functional theory (TD-DFT) at CAM-B3LYP and B3LYP calculations on triazines 1–4 were performed, in which TD-DFT/CAM-B3LYP results show good agreement with the experimental results. The nonlinear optical properties of triazines 1–4 were studied under femtosecond laser pulse excitation at 800 nm using the Z-scan technique. Large two-photon absorption coefficient value (1.8 × 10−13 m/W) was obtained for highly conjugated triazine 4. These triazines can serve as on optical limiter toward, high intensity short pulses.