The Water-Soluble Zinc Phthalocyanine Substituted with Sulfur-Containing Groups

Abstract

In this paper we describe [phthalocyaninato]zinc octakis (methylene isothiuronium) chloride and [phthalocyannato]zinc octamethanethiol having as the starting substance octakis(cloromethyl) phthalocyanine zinc obtained by chloromethylation reaction of zinc phthalocyanine. The structures of the synthesized compounds were characterized by elemental analysis, FTIR and 1H-NMR spectroscopies. The UV–Vis spectra of mentioned compounds depend on its concentration and generally present, a wavelength region with – the B band situated at approx. 300–400 nm and the Q band at approx. 600–800 nm. The UV–Vis spectra of [phthalocyaninato]zinc oktakis (methylene isothiuronium) chloride presented a broader Q-band in water solution with a shoulder on the red side. It is noticeable, the disappearance of Q peak splitting, with a slight hypsochromic shift at 639 nm, characteristic of the α-form of aggregation. Laser flash photolysis has been used to characterize the triplet state of [phthalocyaninato]zinc oktakis (methylene isothiuronium) chloride compound in dilute DMSO: H2O, NVP: H2O and H2O solutions. The fluorescence decay curves for [phthalocyaninato]zinc oktakis (methylene isothiuronium) chloride at the interval of excitation wavelengths (λexc = 341…703 nm) show a biexponential behavior with lifetime values being yielded 2.31 μs and 1.23 μs in DMSO: H2O, 1.22 μs and 9.22 μs in NVP: 9H2O solvents. The decay curve of phosphorescence of [phthalocyaninato]zinc oktakis (methylene isothiuronium) chloride in H2O are multi-exponential and are represented by the relatively long triplet lifetimes of 1.09 µs, 4.96 μs and 15.23 μs. The triplet lifetime and triplet quantum yield values of [phthalocyannato]zinc octamethanethiol in DMSO: H2O are lower than of [phthalocyaninato]zinc octakis (methylene isothiuronium) chloride compound.