Synthesis and Photophysical Properties of A3B-type Unsymmetrically Substituted Anthracene-based Zinc(II)phthalocyanine

Abstract

A novel unsymmetrical zinc(II) phthalocyanine (ZnPc) (3) with an alkynyl functional group wasprepared by an efficient mixed statistical condensation of 4-((4-ethynylbenzyl)oxy)phthalonitrile (1) and4-(4-tertbutylphenoxy)phthalonitrile (2). FTIR, 1H NMR, UV-Vis, elemental analysis, and MALDI-TOF wereused to characterize this new compound. Working with different concentrations, the compound’saggregation properties were investigated and concluded that no aggregation tendency has been observedin the studied concentration range (1.0 x 10-6 M to 1.2 x10-5 M). Fluorescent quantum yields and lifetimesof the compound were studied and found to be 0.09 and 0.57 ns, respectively. As a fluorescent quencher,1,4-benzoquinone was used in the experiments at differing concentrations in tetrahydrofuran. The kqvalues showed a close follow-up to the diffusion control limits, around 1011 s-1 and they seem to agreewith Einstein-Smoluchowski’s approximation for bimolecular, diffusion-control-including, interactions. Forthe new compound, the KSV value was calculated as 27.55, which is lower than that of unsubstitutedZnPc. The fluorescence of the studied compound 3 was effectively quenched by 1,4-benzoquinone.