A Kinetic Study of the System Phthalocyanine-Copper(II) Chloride-Sulfuric Acid

Abstract

In solutions of phthalocyanine, H2Pc, (c = 1–3 × 10−5 mol dm−3) and copper(II) chloride (c ≈ 10−3 mol dm−3) in sulfuric acid (c = 16–18 mol dm−3), two pseudo first-order reactions take place: (1) decomposition of H2Pc; (2) conversion of H2Pc into copper(II) phthalocyanine, CuPc. Reaction (1) is H2O concentration dependent and its rate constant increases from 0.088 to 1.88 h−1 as the H2SO4 concentration changes from 18 to 16 mol dm−3. The rate constant of (2) does not vary significantly with H2SO4 concentration and lies around the 0.05 h−1 mark. The CuPc formed in reaction (2) does not decompose under the above conditions.