Synthesis, spectroscopic and DFT characterization of 4 β -(4-tert-butylphenoxy) phthalocyanine positional isomers for non-linear optical absorption

In this work the synthesis, spectral characterization and non-linear optical properties of metal-free 4β-(4-tert-butylphenoxy) phthalocyanine isomers are described and compared to the previously reported alpha derivative. The second-order nonlinear optical properties of the phthalocyanine isomers were investigated using the Z-scan technique and compared to the theoretical data obtained from density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations. Z-scan results indicated strong non-linear behaviour, revealing reverse saturable absorption (RSA) profiles for all four isomers. The experimental βexp values showed the following trend:C4h (9.31×10–10mMW–1)>D2h (7.89×10–10mMW–1)>Cs (7.32× 10–10 mMW–1) > C2v (1.77 × 10–10 mMW–1). These results were similar to that obtained with the 4β-(4-tert-butylphenoxy) phthalocyanines as the C2v and Cs isomers were found to have the lowest βexp values compared to other symmetries. The 4β-(4-tert-butylphenoxy) phthalocyanine C4h isomer was found toshowbetter non-linear optical properties compared to all other isomers.Keywords: Phthalocyanine, non-linear optical absorption, density functional theory, magnetic circular dichrois

Spectroscopic and nonlinear optical properties of alkyl thio substituted binuclear phthalocyanines

This work presents the spectroscopic and nonlinear optical properties of metal free binuclear and monomeric 4- (pentylthio)phthalocyanine and cobalt 4,5-(bipentylthio)phthalocyanine. Second order nonlinear absorption coefficient (β) values for the complexes were determined and compared