Modification of interfacial reactivity by the microenvironment. Metallation of porphyrins in monolayer films and assemblies

Photochemical reactivity in organized assemblies. 15. Photoreactions of metalloporphyrins in supported monolayer assemblies and at assembly-solution interfaces. Reductive addition of palladium complexes with surfactant and water-soluble dialkylanilines

“…For the "picket fence" porphyrin H2PF,THA (the a,a,a,a atropisomer in which the O-amino groups have been converted to hexadecylamides) the substitution of four relatively large hydrophobic groups on one side of the porphyrin forces the porphyrin to occupy a site in which one face of the porphyrin is in a relatively hydrophilic region at or near the film-water interface in films or a hydrophilic-hydrophilic contact plane in deposited multilayers. 14 In contrast previous studies suggest that the other porphyrin used in these studies, meso-tetra(4-carboxyphenyl)porphyrin tetraoctadecyl ester (TCP,TOE), resides in a more hydrophobic site and that the porphyrin ring is probably bent back from the plane of the film or film layer in multilayers.14,35,41 Since the palladium(II) complexes of porphyrins do not normally strongly coordinate extraplanar ligands,47 it appears reasonable to assume that the palladium porphyrins used in this study, PdPF,THA and PdTCP,TOE, would occupy sites in monolayer films and assemblies similar to those of the respective free bases. This expectation is supported by our findings of very similar surface pressure-area characteristics for films of the palladium complexes and free bases in both cases.…”

Porphyrin–phospholipid interaction and ring metallation depending on the phospholipid polar head type

“…It is known metallation of the porphyrin ring considerably changes the optical properties of the molecules, and the metallation reaction in bulk media can be fastened in the presence of anionic polyelectrolytes [19]. Whitten et al [20] have demonstrated that the porphyrin metallation in an organized media can be correlated with the microenvironment of the porphyrin; porphyrins in hydrophilic sites in or near the interface are readily metallated while those in more hydrophobic sites are not. They showed that the insertion of copper into different porphyrinic rings is strongly dependent on the orientation of each porphyrin at the interface.…”

Effect of Transition Metal Cations on Assembly of Highly Ordered 2D Multiporphyrin Arrays on Liquid and Solid Substrates

“…До сих пор возможность осуществления реакции металлирования в монослоях рассматривалась лишь в нескольких работах. [22][23] Поскольку известно, [24][25] что оптические спектры мезо-замещенных порфиринов чув-ствительны к реакции катионов с полостью макроцикла и слабо зависят от изменений в периферийных группах, спектры поглощения и флуоресценции, записанные in situ для монослоев на поверхности жидкости, будут отражать именно этот процесс. Степень взаимодействия периферийных групп в монослое мы впервые предлага-ем определять, анализируя как положение, так и форму изотерм сжатия монослоев.…”