A series of polycyclic aromatic hydrocarbon-substituted metal-free porphyrins: Substituent effect on two-photon absorption property

Abstract

The third-order nonlinear optical properties of a series of naphthyl, phenanthrenyl, and pyrenyl substituted porphyrins have been comparatively investigated by performing the femtosecond-pulsed Z-scan measurements. Due to the expanded π system, both pyrenly substituted porphyrin (1) and phenanthrenly substituted porphyrin (2) exhibit large two-photon absorption cross sections up to 4.26×10 4 GM for 1 and 1.36×10 4 GM for 2 at the wavelength of 800 nm. The pyrenly substituted porphyrin (1) has the most excellent two-photon absorption property because of the intramolecular energy transfer from the excited pyrene moiety to the porphyrin moiety in porphyrin 1. The results confirm that porphyrins conjugated with external π electronic systems can lead to the significant enhancement in the twophoton absorption cross-section values. This research provides a useful guideline to the design of efficient two-photon absorbing materials.

Verbenone‐based push–pull chromophores with giant first hyperpolarizabilities: A new structure–property correlation study

“…Multiphoton processes find extensive use in fluorescence microscopy, 3D data storage, optical power limiting and two-photon photodynamic therapy with specifically designed organic chromophores [21][22][23][24][25][26][27][28][29]. However, experimental identification of two-dimensional nonlinear optical responses of materials to external fields with continuously varying frequency in a wide range is not an easy task [30].…”