Flexible dizinc diporphyrin systems as selective receptors for ditopic amine ligands

Zinc(II) diporphyrin systems, characterised by the presence of flexible oligooxaethylene spacers of different lengths, have been synthesised and the binding properties toward a series of aliphatic and aromatic diamine derivatives characterised by different structural and coordination properties, investigated. The results obtained, compared to that for a rigid diporphyrin cleft, point out that the observed degree of selectivity is dependent both on the length of the spacer and on the nature of the nitrogen ligands. Copyright (C) 2002 Society of Porphyrins & Phthalocyanines.