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

First- and second-generation dendritic porphyrins were synthesized by casca de polymer methodology. The second molecular hyperpolarizabilities (gamma) of these dendritic porphyrins as well as 5,10,15,20-tetraphenylporphyrin we re measured by the Z-scan technique at 800 nm using a mode-locked Ti:sapphi re laser. The relationship between the various structures and their corresp onding second molecular hyperpolarizabilities are explained on the basis of the oscillator strength of the Q band and the increasingly electron-rich m icroenvironment created by the dendritic branches around the porphyrin core . Copyright (C) 2000 John Wiley & Sons, Ltd.