Supramolecular isomerism of self-complementary zinc-5,10,15,20-tetra(4-pyridyl)porphyrin in the presence of dimethylformamide

Abstract

Supramolecular isomerism by self-complementary coordination in the system zinc-5,10,15,20-tetra(4-pyridyl)porphyrin (ZnTPyP)–dimethylformamide (DMF) is reported. Recrystallization of ZnTPyP from DMF afforded crystals of a new tetrameric supramolecular isomer, [ZnTPyP]₄·7.33DMF, with molecular and crystallographic S₄ symmetry. The crystals were accompanied by triclinic crystals of [ZnTPyP·2DMF]_n with a polymeric 1D ladder structure. In situ metalation of the parent free-base 5,10,15,20-tetra(4-pyridyl)porphyrin (TPyP) with Zn²⁺ in dimethylformamide afforded monoclinic crystals of [ZnTPyP·2.33DMF]_n with a 1D double zig-zag chain structure. The ZnTPyP–DMF system is an example of unusual supramolecular isomerism in metallosupramolecular chemistry.