22.02.2023
Metal-free phthalocyanine (PcH2) was synthesized as follows. A mixture of o-phthalonitrile and Mg metal was heated to 220°C, followed by demetallation with cold concentrated H2SO4.
To synthesize iron phthalocyanine chloride (PcFeCl), a mixture of PcH2 (0.5 g, 0.97 mmol), 6-fold molar excess of FeBr2·4H2O (1.68 g, 5.84 mmol) and catalytic amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in pyridine was refluxed for 160 h in an argon atmosphere. The progress of the reaction was monitored by UV-vis spectroscopy (PcH2/PcFePy2). After completion of the reaction, distilled water was added to the reaction mixture. After precipitation of the reaction product, the resulting solution was filtered and the filtrate was washed with distilled water. The obtained dark powder was treated with concentrated HCl followed by vacuum drying at 90°C. This yielded PcFeCl (0.585 g, 99.7%) powder which was confirmed by UV-vis spectroscopy in pyridine (λmax/nm (log ε): 333 (4.83), 413 (4.23), 593 (4.44), 654 (5.04)). The experimentally determined contents (at.%) of C (59.95), H (3.20), and N (17.45) are in good agreement with those calculated on the basis of the formula C32H16N8FeCl·2H2O: C (60.07), H (3.15), and N (17.51).