Porphyrin and Metalloporphyrin Fibres

Attempts to co-crystallize amphiphilic porphyrins with micellar fibres failed completely. The van der Waals interactions between porphyrin planes ( stacking ) are so strong that unsubstituted porphin and (3-octamethylporphyrin are insoluble in practically all solvents. Porphyrins with larger substituents such as ethyl or acetic acid side chains allow face-to-face dimerization only, an action which occurs in all solvents and also probably in micelles down to a concentra- 

Quantitative heterodimerization without precipitation was achieved between 5,10,15,20-tetrakis( A-methylpyridinium-4-yl)porphyrins and 4,4, 4, 4 - 

Strength of two metal complexes was weak in comparison to a free base-metal complex pair. Furthermore, heterotrimers of the sandwich type with two porphyrins separated by a phthalocyanine were occasionally obtained or vice 

Large metal ions such as thorium or uranium were also employed in order to combine a porphyrin, octaethylporphyrin (OEP), with a phthalocyanine (Pc) chromophore in face-to-face or double-decker orientation. and Th compounds could be electrogenerated in up to seven different oxidation states. The first two reductions occurred mainly on the Pc ring while the first two oxidations of the same heteroleptic compounds involved primarily orbitals of the porphyrin macrocycle. In contrast, the homoleptic (MP)2 and (MPc)2 derivatives undergo initial one-electron oxidations and reductions which are localized not at a single ring, but involve both macrocycles.  

In complete contrast to metalloporphyrins, the analogous metallochlorins showed no attractive interactions whatsoever. An important assembly occurred in the case where the keto oxygen of the isocyclic ring in chlorophylls bound to the central magnesium ion of another molecule. Dimers with an interplanar separation of 4.2. 7 A were formed. A series of earlier papers handled the characterization of such dimers by H-NMR and IR spectrosco-pies o ei, their behaviour has been compared with covalently connected dimer 

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