Tetrahydroxyphthalocyanine as a potential nonlinear optical material

We have synthesized a new zinc(II)-phthalocyanine (ZnPc) incorporating hydroxyl groups at the pe-ripheral positions. This new zinc(II)-tetra-hydroxyphthalocyanine ( 1 ) has been characterized by high -resolution MALDI TOF MS, UV-Vis, FT-IR (ATR), and 1 H-and 13C-NMR techniques, and further by the electrochemical measurements. DFT and TD-DFT computations were performed to model plausible struc-ture and also analyze the electronic structure and optical properties of 1 . The effects of the polarity and hydrogen bonding ability of the hydroxyl substituents on the peripheral positions of 1 on the optical and electrochemical properties are reported in this study. The redox behavior of 1 in dimethyl sulfoxide (DMSO) was determined by voltammetry and colorimetry supported in situ spectroelectrochemistry. The nonlinear absorption and optical limiting (OL) properties of 1 were measured in tetrahydrofuran (THF) by utilizing the open aperture Z-scan technique with nanosecond pulses at 532 nm. The sample demon-strated good reverse saturable absorption and OL behaviors. The ultrafast pump-probe experiments re-vealed the intersystem crossing (ISC) mechanism (triplet-triplet transition) and the nonlinear absorption mechanism of the compound. The results indicate that this new phthalocyanine ( 1 ) can be considered a potential candidate for low-power OL applications.(c) 2022 Elsevier B.V. All rights reserved.