Synthesis, photophysical, photochemical, and DFT properties of a zinc phthalocyanine with 2-(2-isopropyl-5-methylphenoxy)phenoxy peripheral groups

The 2-nitrophenol and 4-nitrophthalonitrile reagents were mixed in the presence of potassium carbonate in dimethylformamide (DMF) under N2 at room temperature. Then, by adding thymol(5-methyl-2-isopropylphenol) and continuing the reaction, 4-(2-(2-isopropyl-5-methylphenoxy)phenoxy)phthalonitrile was obtained. Zinc phthalocyanine (4) was formed from the reaction of ZnCl2 and 4-(2-(2-isopropyl-5-methylphenoxy)phenoxy)phthalonitrile (3) at 190 °C. Both compounds were soluble in most organic solvents. Compounds 3 and 4 were characterized by mass, infrared, electronic absorption and nuclear magnetic resonance spectroscopies. The concentration–absorption relationship of 4 was examined by UV spectroscopy. The photophysical and photochemical properties of 4 were investigated. The geometry-optimized structures of 4 were investigated with the DFT approach, B3PW91/6-31G (d,p), and B3LYP/LanL2DZ basis set. Energy properties, first order hyperpolarizability, and Fukui function calculations were also performed. Natural bond orbital analysis was performed to explain the charge transfer (or) charge delocalization due to intramolecular interactions in phthalocyanine.