Porphyrin rotaxanes and catenanes: Copper(I)-templated synthesis and photoinduced processes

The approach based on the copper(I)-templated synthesis of porphyrin catenanes and rotaxanes developed by the authors' group is here reviewed. Zn(II) porphyrins and gold(III) porphyrins were chosen as electron donors and electron acceptors, respectively, to constitute the electro- and photoactive parts of the present systems. The processes-energy and electron transfer reactions-occurring in the interlocked structures upon light absorption in the presence or absence of Cu(I) are presented, their rates and efficiencies critically compared and discussed with respect to properties of the components and of the ensemble. A detailed examination of differences and analogies in photoreactivity between the present and closely related systems reported by others is presented.