Metalporphyrinphthalocyanine

Metalporphyrinphthalocyanine refers to coordination compounds in which a metal ion is bound by both a porphyrin and a phthalocyanine macrocycle. In these systems, the two macrocycles can be connected in different ways: as a dyad where the metal links the rings, as a cofacial double-decker assembly, or as a covalently fused unit. The combination leverages the complementary electronic and photophysical properties of porphyrins and phthalocyanines, allowing tuning of the metal’s coordination environment and the overall electronic structure through metal choice and substituents.

Typical metals used include transition metals such as iron, manganese, copper, and zinc, as well as other elements in specialized architectures. The coordination geometry depends on the metal and the ligand arrangement; the macrocycles usually bind through their core nitrogens, with additional axial ligands or bridging groups completing the coordination sphere in some designs.

Synthesis strategies encompass assembling the metal with preformed porphyrin and phthalocyanine units via axial coordination, templated or stepwise condensation to yield dyads, and covalent linking of the macrocycles followed by metal insertion. Purification and structural confirmation commonly rely on chromatography, mass spectrometry, UV–visible spectroscopy, and, when possible, X-ray crystallography.

Spectroscopic features reflect the combined macrocycles: porphyrins contribute the Soret band and Q bands, while phthalocyanines provide intense near-infrared Q-band absorption; electronic coupling between rings can shift bands and modify redox properties. Electrochemical studies typically reveal reversible redox processes associated with the metal center and the macrocycles.

Applications span electrocatalysis and photocatalysis (e.g., oxygen reduction, CO2 reduction, water splitting), energy conversion and storage, dye-sensitized solar cells, molecular electronics, and, in some cases, photodynamic therapy.