Thermochemistry of the Dissolution of Copper Tetra-3-carboxyphtalocyanine in Aqueous Solutions of KOH at 298.15 K

A complex of tetra-3-carboxyphthalocyanine with copper that is insoluble in water is obtained. Thermal effects from dissolving crystalline tetra-3-carboxymetalphthalocyanine in aqueous solutions of various KOH concentrations (from 0.002 to 0.02 mol/L) at 298.15 K are determined via direct calorimetry. Measurements are made in a calorimeter using an isothermal shell with automatic recording of the temperature and electrical calibration at T = (293.15–308.15) ± 0.01 K and P = 100.5 ± 0.7 kPa. Standard enthalpies of formation of the products of dissociation of the tetra-3-carboxyphthalocyanine complex with copper in aqueous solution are calculated. Thermal effects of stepwise dissociation are calculated using the HEAT computer program.