Sythehsis, characterization and the investigation of spectroscopic properties of 2-bromo-4,5-dimethoxybenzyloxy substitue phthalocyanine compounds

Phthalocyanines are compounds discovered by chance in the early twentieth century which derived by Linstead from naphtha and cyanine, the words mean rock oil and dark blue in ancient Greek literature. Phthalocyanines can be synthesized as metal and metal-free which have 18-π electrons, blue and green colors. Phthalocyanines are man-made macrocyclic compounds. Since the first synthesized, they were an important class of dyes and pigments due to their chemical and physical properties. Today, phthalocyanines are used in many applied sciences such as catalysis, photodynamic therapy (PDT), chemical sensors and optical materials and many researches are carried out on phthalocyanines. The solubility, physical and chemical properties of the phthalocyanines vary depending on the ligand, as well as the metal ion at the center of the phthalocyanine. Phthalocyanines have an intense absorption capacity in the red region of visible light. In addition, they have long triplet state and effective singlet oxygen production capacity. Therefore, the use of these compounds as a second-generation photosensitizing agent in PDT, a type of cancer treatment, has gained importance in recent years. In this study, new metallo phthalocyanine compounds were synthesized which were not previously synthesized using 2-bromo-4,5-dimethoxybenzyl alcohol. Zinc (Zn), magnesium (Mg) and indium (In) metal salts were used in the synthesis of phthalocyanines. In the first part of the study, 2-bromo-4,5-dimethoxybenzyl alcohol was reacted with 3-nitrophthalonitrile and 4-nitrophthalonitrile in the presence of potassium carbonate (K2CO3) in dimethylformamide (DMF), respectively. At the end of the reaction, 3-(2-bromo-4,5-dimethoxybenzyloxy)phthalonitrile (1) and 4-(2-bromo-4,5-dimethoxybenzyloxy)phthalonitrile (2) ligands were obtained. In the second part of the study, these two ligands were reacted with the appropriate metal salts in nhexanol in the presence of 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU). At the end of the reaction, non-peripheral and peripheral metallo phthalocyanine compounds (np-ZnPc, np-MgPc, np-InClPc, p-ZnPc, p-MgPc, p-InClPc) were synthesized. For the elucidation of the structure of the synthesized compounds; FT-IR, 1H-NMR and MALDI-TOF were used. Photophysical and photochemical properties of the phthalocyanine compounds were investigated using UV-Vis and fluorescence spectrophotometer devices. The results of the novel phthalocyanines containing the 2-bromo-4,5-dimethoxybenzyloxy substituent synthesized by this thesis are compiled and presented in the literature with the information on phthalocyanines.