Porphyrin oligomeric

Research Focus Synthesis of oligomeric porphyrins for use as free radical traps in humans. Originality The preparation of oligomers and polymerizable porphorins for use in... 

These two molecules were the antecedents of a variety of oligomeric porphyrin and chlorophyll derivatives which were constructed as mimics of the reaction center special pair. Many of these systems exhibit interesting optical properties which allow modelling of the electronic interactions within the special pair and/or the antenna function of chlorophyll, which involves singlet-singlet energy transfer... 

While self-assembled and aggregated chirogenic systems are mainly based on monomeric porphyrinoids, a further increase of the pigment multiplicity, despite raising the overall complexity of supramolecular structures, may lead to novel functional properties and new applications. Therefore, in the last section we shall show a few examples of self-assembled and aggregated systems constructed from dimeric and oligomeric porphyrins. 

Fig. 7.22 (a) Retrosynthetic synthesis of porphyrin oligomers without amine templates. [After Sanders et ah] (b) Synthesis of porphyrin oligomers with amine templates. [After Sanders et at.] (c) Synthesis of oligomeric porphyrins binding a metal-carbonyl cluster and a chiral aluminium template. 

Fig. 7.35 Construction of edge to edge ladder oligomeric porphyrins. Ar = an aromatic tetrammine.

Already in the beginning of the history of concave reagents, the template effect of metal cations was utilized, but also organic molecules can be applied. Sanders for instance used the interaction of pyridines with zinc porphyrins in the construction of macrocyclic oligomeric porphyrins, and recently, the interaction between polyols and boronic acids has been used in order to synthesize new mdo-fimctionalized macrocycles (Figure 7.14) ... 

Haycock RA, Hunter CA, James DA, Michelsen U, Sutton LR. Selfrassembly of oligomeric porphyrin rings. Org Lett. 2000 2 2435-2438. 

Tetrakisporphyrin and oligomeric porphyrin An approach to molecular electronic wire Tetrakisporphyrin (C322H370N28) is about 65 A long. The tert-butyl groups along the backbone provide an insulating sheath around the conjugated core and enables solubility. [64]... 

The electron transport from dimer porphyrin to the terminal pyromellitdii-mide or quinone afford the ion pair with a lifetime in the order of is (32,33) [569,570] and long lifetime of 16 ps in THF (34) [574]. Obviously, the lifetimes of ion pairs were roughly in the order of diad < triad < tetrad < pentad systems. Other approaches such as proton coupling to the electron transfer [576] as observed in photosynthesis [575], enhancement of electron transfer by pyridine coordination to the central metal [577], and linked molecular systems having oligomeric porphyrins [572-574], carotenoide [543,582-589], aromatic molecules [590-594,753,754], cleft-type [789], [578-581], and Q, [477,595-599,... 

Monomeric and Oligomeric Porphyrins in Bulk Heterojunction Solar Cells... 

In few cases linear chain structured polymeric metal complexes were prepared. A linear polymeric phthalocyanine 60 was obtained as film by the electrochemical polymerization of the corresponding monomer [260]. The synthesis of structural uniform ladder polymers 61 based on the hemiporphyrazine structures was achieved by a repetitive Diels-Alder reaction [261,262]. Recently, linear oligomeric porphyrines covalently connected via meso-meso-positions up to 128 units were synthesized [263]. 

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