Dendritic porphyrins: synthesis and third-order optical non-linearity

Abstract

First- and second-generation dendritic porphyrins were synthesized by cascade polymer methodology. The second molecular hyperpolarizabilities (γ) of these dendritic porphyrins as well as 5,10,15,20-tetraphenylporphyrin were measured by the Z-scan technique at 800 nm using a mode-locked Ti:sapphire laser. The relationship between the various structures and their corresponding second molecular hyperpolarizabilities are explained on the basis of the oscillator strength of the Q band and the increasingly electron-rich microenvironment created by the dendritic branches around the porphyrin core.