Photophysical and nonlinear optical studies of tetraakynyl zincphthalocyanine and its “clicked” analogue

•Tetra-substituted alkynyl zinc phthalocyanine and its “clicked” analogue are synthesized.•Two-photon absorption and reverse saturable absorption are the dominant nonlinear absorption mechanisms.•The presence of electron acceptor groups fused with triazole linkers enhanced photophysical and nonlinear optical behavior.

We report here for the first time on the photophysical and nonlinear optical behavior of tetra-substituted alkynyl zinc phthalocyanine and its “clicked” analogue (4 and 5). The compounds exhibited high triplet quantum yields in dimethylsulphoxide (DMSO). Nonlinear optical (NLO) properties were also evaluated for the two compounds at 532 nm and 10 ns in DMSO. We observed two-photon absorption (2PA) and strong reverse saturable absorption (RSA) as the dominant mechanisms at nanosecond laser excitation. The presence of electron acceptor groups fused with triazole linkers in the peripheral positions of 4 provide excellent coexistent features, such as enhanced triplet quantum yields and lifetimes compared to 5. Large third-order susceptibility (2.09 × 10−11 and 3.53 × 10−9 esu) and hyperpolarizability (1.09 × 10−30 and 9.13 × 10−29 esu) were estimated for complexs 4 and 5, respectively.

Graphical abstractTetra-substituted alkynyl zinc phthalocyanine and its “clicked” analogue exhibit strong triplet absorption with high triplet yields. Both two-photon absorption and reverse saturable absorption are the dominant mechanisms for nonlinear absorption.Figure optionsDownload full-size imageDownload as PowerPoint slide