Effect of N atoms in the backbone of metal phthalocyanine derivatives on their catalytic activity to lithium battery

Metal phthalocyanine (MPc, M = Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺ and Cu²⁺), metal tetrapyridinoporphyrazine, and metal tetrapyrazinoporphyrazine are synthesized by microwave reaction and characterized by elemental analyzer, IR spectroscopy and UV-vis spectroscopy. The catalytic activity of MPc derivatives to Li/SOCl₂ battery is evaluated by the relative discharge energy of the battery whose electrolyte contains the compounds. The discharge energy of Li/SOCl₂ battery catalyzed by MPc is approximately 0-61% higher than that of Li/SOCl₂ battery in the absence of compounds, depending on the central metal ion. To the same central metal ion, the discharge energy of Li/SOCl₂ battery catalyzed by MTAP is approximately 60% higher than that by MPc. The discharge energy of Li/SOCl₂ battery in which SOCl₂ contains MPTpz is approximately 17-19% higher than that of the battery in the absence of compounds, and almost independent of central metal ions. It shows a correlation existing between the structure and the catalytic active sites of MPc derivatives. The double active site model is proposed to interpret the results.