1. Noncovalent synthesis in aqueous solution and spectroscopic characterization of multi-porphyrin complexes
- Author
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Silvano Geremia, Rita De Zorzi, Roberto Purrello, Rosaria Lauceri, Fabio Giuseppe Gulino, Limor Frish, Yoram Cohen, Lucio Randaccio, Tamar Evan-Salem, Luigi Di Costanzo, Domenico Sciotto, Gulino, F. G., Lauceri, R., Frish, L., EVAN SALEM, T., Cohen, Y., DE ZORZI, Rita, Geremia, Silvano, DI COSTANZO, L., Randaccio, Lucio, Sciotto, D., Purrello, R., Evan-Salem, T., De Zorzi, R., Geremia, S., DI COSTANZO, Luigi, Randaccio, L., and Purrello, Francesco
- Subjects
Magnetic Resonance Spectroscopy ,Porphyrins ,Stereochemistry ,chemistry.chemical_element ,Noncovalent synthesi ,Zinc ,Catalysis ,WATER CHEMISTRY ,Porphyrin ,chemistry.chemical_compound ,CALIXARENES ,SUPRAMOLECULAR CHEMISTRY ,Calixarene ,Deuterium Oxide ,Porphyrin Complex ,Noncovalent interaction ,Aqueous solution ,biology ,Molecular Structure ,Chemistry ,Organic Chemistry ,Cationic polymerization ,Water ,Self-assembly ,General Chemistry ,biology.organism_classification ,Template synthesi ,Crystallography ,Spectrometry, Fluorescence ,Solubility ,Tetra ,Spectrophotometry, Ultraviolet ,Calixarenes ,Porphyrinoid ,Stoichiometry - Abstract
The interactions of the tetra- cationic meso-tetrakis(N-methyl-4-pyri- dyl)porphyrin (H2TMPyP) and its met- allo derivatives (MTMPyP) (where M = copper(ii), zinc(ii), and gold(iii) with the octa-anionic form (at neutral pH) of 5,11,17,23-tetrasulfonato- 25,26,27,28-tetrakis(hydroxycarbonyl- methoxy)calix(4)arene (C4TsTc) lead to a series of complex species whose stoichiometry and porphyrin sequence can be easily tuned. Crystallographic, spectroscopic, and diffusion NMR stud- ies converge towards a common picture in which a central 1:4 porphyrin/calix- arene unit serves as a template for the formation of more complex species. These species arise by successive, step- wise addition of single porphyrin mole- cules above and below the plane of the 1:4 central core to ultimately give a 7:4 complex. Noticeably, the stoichiometry of the various complex species corre- sponds to the actual concentration ratio of porphyrins and calixarenes in solution allowing the stoichiometry of these species to be easily tuned. This behavior and the remarkable stability of these species allow homo-porphyrin and hetero-(metallo)porphyrin species to be formed with control of not only the stoichiometry but also the sequence of the porphyrin array. The flexibility and ease of this approach permit, in principle, the design and synthesis of porphyrin arrays for predetermined purposes. For example, we have shown that it is very easy to design and obtain mixed porphyrin species in which a foreseen photoinduced electron-trans- fer is indeed observed.
- Published
- 2006