Mechanisms of aggregation in metalloporphyrins: demonstration of a mechanistic dichotomy

Abstract

N.m.r. spectroscopy is used to demonstrate that the predominant interaction in aggregations of magnesium(II) porphyrins [e.g.(1)] involves the metal atom in one molecule and the propionate carbonyl group in another; in contradistinction, the similarly strong aggregation observed for the first time in zinc(II) porphyrins [e.g.(2)] is shown to be independent of a metal to side-chain interaction.