Crystallization of chloroindium(iii)octaethylporphyrin into a clamshell motif to engulf guest molecules

Abstract

X-Ray diffraction studies are reported for six forms of ClIn^III(OEP) (OEP is the dianion of octaethylporphyrin): ClIn^III(OEP), ClIn^III(OEP)·1.5 benzene, ClIn^III(OEP)·1.5 pyridine, ClIn^III(OEP)·0.5p-dioxane·benzene, ClIn^III(OEP)·1.5 chlorobenzene, ClIn^III(OEP)·C₆₀·benzene. All crystals involve a square pyramidal coordination geometry about the indium ion with the chloride ion occupying the axial position and the four nitrogen atoms of the porphyrin defining the equatorial plane. In five of the structures the ethyl groups adopt an arrangement where they protrude outward on the opposite side of the porphyrin from the axial chloride so that they can encapsulate a guest. Pairs of ClIn^III(OEP) molecules have been found to encapsulate molecules of benzene, pyridine, p-dioxane and chlorobenzene in a novel clamshell-like arrangement.