CONTENTS

Electrocatalytic reduction of oxygen with phenanthroline-strapped porphyrins Frédéric Melin, Corinne Boudon, Mamadou Lo, Kurt J. Schenk, Michel Bonin, Philippe Ochsenbein, Maurice Gross and Jean Weiss* DOI: 10.1142/S1088424607000278 Page: 212-221 Three derivatives of a phenanthroline strapped porphyrin framework catalyze the electro-reduction of oxygen. A two electron reduction process is observed in solution when axial base is absent, while catalysts adsorbed on graphite/platinum ring disk electrodes perform an efficient four electron reduction of oxygen into water. Supplementary Material
Metal phthalocyanine showing four-peak Q-band similar to metal-free phthalocyanines: nickel 1,4-di(trifluorosulfonyl)phthalocyanine Katunori Nakai, Jyo Usami and Nagao Kobayashi* DOI: 10.1142/S108842460700028X Page: 222-227 Nickel Pcs substituted by only one or two electron-withdrawing trifluorosulfonyl or electron-donating trimethylsilylethynyl groups, at α positions of a benzene ring of the Pc skeleton, have been synthesized. In particular, NiPc substituted by two trifluorosulfonyl groups exhibits an absorption spectrum characteristic of metal-free Pcs. The cause of the large splitting of the Q-bands has been explained theoretically.
The photophysics of metalloporphyrins excited in their Soret and higher energy UV absorption bands Umakanta Tripathy and Ronald P. Steer* DOI: 10.1142/S1088424607000291 Page: 228-243 Photophysical processes involving the higher electronic excited states of diamagnetic porphyrins and metalloporphyrins are critically reviewed. Intramolecular electronic relaxation of one-photon Soret-excited molecules in solution is now known to involve processes other than S2 - S1 internal conversion; dark electronic states are implicated. Non-linear phenomena associated with multi-photon excitation of diamagnetic metalloporphyrins are also reviewed.
Through space singlet-singlet and triplet-triplet energy transfers in cofacial bisporphyrins held by the carbazoyl spacer Claude P. Gros, Shawkat Mohammed Aly, Maya El Ojaimi, Jean-Michel Barbe, Frédéric Brisach, Alaa S. Abd-El-Aziz*, Roger Guilard* and Pierre D. Harvey* DOI: 10.1142/S1088424607000308 Page: 244-257 The through space singlet-singlet and triplet-triplet energy transfers in cofacial bis(etio-porphyrins) rigidly held by the carbazoyl spacer was investigated. The singlet-singlet transfer studies were performed using the zinc porphyrin and free base chromophores as energy donor and acceptor, respectively, while the investigation on triplet-triplet processes was performed using the palladium porphyrin, and the zinc porphyrin and free base chromophores as donor and acceptors, respectively. Supplementary Material
Great adaptability of the heme-cysteinate monooxygenases family to very diverse substrates and sophisticated reactions Daniel Mansuy* and Pierre Lafite DOI: 10.1142/S108842460700031X Page: 258-268 Heme-cysteinate monooxygenases play a key role in the adaptation of aerobic organisms to their always changing environment. They are able to oxidize so many different substrates by offering a great choice of very diverse and malleable active sites. They also catalyze special, sophisticated reactions by using supplementary cofactors adapted for the required catalysis.
Free-base corroles: determination of deprotonation constants in non-aqueous media Jing Shen, Zhongping Ou, Jianguo Shao, Michał Gałęzowski, Daniel T. Gryko* and Karl M. Kadish* DOI: 10.1142/S1088424607000321 Page: 269-276 Ten free-base corroles with different meso substituents were examined as to their deprotonation constants by UV-visible spectroscopic titrations with five organic bases in the non-aqueous solvent benzonitrile. Relationships between measured equilibrium constants and the spectroscopic or structural properties of the compounds are discussed.
Extending the self-organization algorithm of chlorosomal bacteriochlorophylls to synthetic pigments Mihaela Carmen Balaban and Teodor Silviu Balaban* DOI: 10.1142/S1088424607000333 Page: 277-286 The self-assembly algorithm encoded by the functional groups of the chlorosomal bacteriochlorophylls can be successfully extended to other chromophores equipped with recognition groups (e.g. X = Y = CHO, or CN) and solubilizing groups (S = C11H23), very different from those encountered in the natural case (X = OH, Y = CO, S = long chain fatty alcohol residue, e.g. farnesol).
Synthesis and characterization of a hexaphyrin(1.0.1.0.0.0) bearing both meso- and β-substituents Jonathan L. Sessler*, Patricia J. Melfi and Vincent M. Lynch DOI: 10.1142/S1088424607000345 Page: 287-293 The synthesis of an isoamethyrin-type expanded porphyrin bearing both meso- and β-substituents is presented. The inner ring current, as inferred from 1H NMR spectroscopic studies, is found to be severly diminished as compared to isoamethyrin by the presence of the two meso-phenyl moieties. The diprotonated form of the macrocycle, as characterized by single crystal X-ray diffraction analysis, was observed to adopt a planar conformation. A second crystal structure, in which a molecule of water is hydrogen-bound to a pyrrole NH, was also solved.

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