Binding of Porphyrins in Cyclodextrin Dimers

摘要

As part of our research program aimed at the development of new supramolecular catalytic systems, we are studying the use of cyclodextrin dimers (CD-dimers) to encapsulate porphy-rins. In this communication we describe the formation of complexes between water-soluble porphyrins and CD-dimers containing flexible spacers. These complexes show a syn- and anti-binding geometry. We also describe an unusual 2:2 (porphyrin:CD-dimer) complex in which two porphyrin molecules are encapsulated by four CD units. The latter units are in dimeric pairs, with the CDs connected via bipyridine spacers. The formation of this complex is facilitated by the addition of a coordinating metal ion.