A comparative study on nonlinear optical properties of zinc porphyrins analogs: Coordination atoms and group effects

Abstract

AbstractDensity functional theory (DFT) has been carried out to investigate the electronic characteristics, UV–VIS–NIR absorption spectra, and nonlinear optical (NLO) properties of two series of zinc porphyrin analogs (FPD‐Nxand TPD‐Nx,x = 0–4) with donor‐π‐donor frameworks. The design of these analogs is based on previously synthesized furan‐linked zinc porphyrins (FPDs) and thiophene‐linked zinc porphyrins (TPDs). It is noted that their electro‐optical features are sensitive to the numbers of N‐coordination atoms and the attached groups. A dramatic enhancement of static first and second hyperpolarizabilities (β0andγ0) occurs when two furan/thiophene rings are attached to the zinc porphyrin. Among the two series, FPD‐N3 and TPD‐N3 have the largestβ0values of about 7600 a.u. The staticγ0values of these complexes range from 0.41 × 106to 1.79 × 106 a.u. The FPD‐Nxhas a largerγ0value than the corresponding TPD‐Nx, but theγ0value of FPD‐N2 is close to that of TPD‐N2. In the dynamic NLO process, the electro‐optical Pockels effect, second harmonic generation, and electro‐optic Kerr effect can be enhanced at the wavelength of 1907 nm. This study provides a new strategy for the experimental design of high‐performance NLO materials.