Spectroscopic and nonlinear optical properties of the four positional isomers of 4α-(4-tert-butylphenoxy)phthalocyanine

Abstract

An enhanced NLO response in terms of both the β and γ values was observed for C4h isomer compared to the other isomers, smallest NLO response were observed for the C2v and Cs isomers, respectively.

Synthesis and Isolation of 2,9,17,23-Tetrakis[(3,5-dimethyl-1H-pyrazol-1-yl)phenoxy]phthalocyanine and Its Magnesium(II) and Zinc(II) Complexes

“…It should be noted that this phenomenon is caused by the fact that metal-free phthalocyanine has Tetrakis[ (3,5-dimethyl-1H-pyrazol-1-yl)phenoxy]phthalocyanine and its Complexes with Magnesium and Zinc lower symmetry due to the absence of a four-fold axis of symmetry. [40] In the 1 H NMR spectra of phthalocyanines 3 and 4 the signals of protons of isoindole fragments (H α , H α′ and H β ) appear as poorly resolved broadened multiplets in low field region. This phenomenon is caused by the fact that due to the small chemical shift difference of protons of four isoindole fragments of C S regioisomer, a signal overlap occurs in the spectra.…”

“…The separation of the mixture of the four regioisomers by column chromatography is highly challenging [40] and was achieved by preparative thin layer chromatography or HPLC with chiral column. [41][42][43][44][45][46] It is known that due to the presence of bulky substitutients, a pure regioisomer of 3-substituted ZnPc can be isolated by column chromatograpy.…”

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

“…31 The Q bands were blue shifted compared to the a derivative. 13 This shift is as a result of an increase in the HOMO-LUMO energy gap which is highly influenced by electron density. The electron-withdrawing nature of the substituents at the alpha position results in the lowering of the energy gap.…”

“…32 The absorption between 400 and 470 nm was attributed to the n ® p* transitions. This transition occurs either as a result of the lone pairs on the outer oxygen atoms 13,33 or the destabilization of the sp 3 hybridized oxygen atoms on the p-MOs.…”

“…11 For the purpose of this study, the isomers are labelled C s , C 2v , C 4h and D 2h to aid with the comparison to metallated phthalocyanine (MPc) complexes in literature. 12,13 In this work, the Z-scan technique combined with DFT calculations will be employed to investigate the NLO properties of the four constitutional isomers of 4b-(4-tert-butylphenoxy)phthalocyanine. Pure isomers may highlight interesting NLO properties which cannot be evaluated in a mixture of isomers.…”