Synthesis of unsymmetrical benzoporphyrazines in functional ionic liquids and formation of self-aggregates of zinc(II) pyridino[3,4]tribenzoporphyrazines in solutions

Abstract

Unsymmetrically substituted metal-free and metallated benzoporphyrazines including pyridino[3,4]tribenzoporphyrazinic macrocycles have been synthesized in good yields by ring expansion reactions of boron(III) subphthalocyanines with phthalonitriles in functional ammonium ionic liquids in the presence of 1,8-diazabicyclo-[5,4,0]-undec-7-ene (DBU) under different reaction conditions. The concentration dependent UV/vis, fluorescence, NMR and ESI-MS spectroscopic data indicate that zinc(II) pyridino[3,4]tribenzoporphyrazines exist as head-to-tail self-aggregates in the solution phase.