Porphyrin assemblies

Fujita and coworkers have also reported the encapsulation of multimeric porphyrin assemblies in the box-shaped cavities of ternary Pd6 coordination cages. Two types of cofacial porphine dimers A and B could be stabilized (133). In the smaller [Pd6(L14)2(L15)6]12+ cage 29, whose diameter is 10.4 A (Fig. 21), two porphyrin molecules can be stackedo directly on top of each other with an interplane distance of 3.4 A. In the larger cage 30, an additional molecule of L14 is intercalated between the two porphyrin bases. All complexes were found to be water-soluble in contrast to other 7i-stacked porphyrin dimers. The encapsulation... 

Tamaru S, Takeuchi M, Sano M, Shinkai S (2002) Sol-gel transcription of sugar-appended porphyrin assemblies into fibrous silica unimolecular stacks versus helical bundles as templates. Angew Chem Int Ed 41 853-856... 

Kleij, A.W., Kuil, M., Tooke, D.M., Spek, A.L. and Reek, J.N.H. (2005) Template-assisted ligand encapsulation the impact of an unusual coordination geometry on a supramolecular pyridylphosphine-Zn(ii) porphyrin assembly. Inorg. Chem., 44, 7696-7698. 

Slagt. V.F., van Leeuwen, P.W.N.M. and Reek, f.N.H. (2003) Midticomponent porphyrin assemblies as functional bidentate phosphite ligands for regioselective rhodium-catalyzed hydroformylation. Angew. Chem., Int. Ed., 42, 5619-5623. 

Non-Covalent Multi-Porphyrin Assemblies Synthesis and Properties Volume Editor Alessio, E. 

Purrello R, Gurrieri S, Lauceri R. Porphyrin assemblies as chemical sensors. Coord Chem Rev 1999 190-192 683-706. 

The ideal template (A) for transferring the chirality to the porphyrin assembly and for the following removal experiment is a fluorescent monomeric chiral... 

Now the last and most important steps to validate experimentally our hypothesis can be performed erase and rewrite the chiral information using solutions of the amino acid-free chiral porphyrin assemblies. 

As the reader can see, we are back, as in a cycle, at the concept expressed at the beginning of the paragraph the importance of the stability and inertness of the core of the porphyrin assembly. Stability and inertness of the core are ensured, as stated, by the extended dimension of the aggregate and, consequently, by the particular local environment conditions. These are quite different from the conditions of the bulk solution, with which the core only partly and indirectly communicates. 

Zhang L, Liu M (2009) Supramolecular chirality and chiral inversion of tetraphenylsulfonato porphyrin assemblies on optically active polylysine. J Phys Chem B 113 14015-14020... 

---