Multiporphyrin dendritic

Fig. 3. A large multiporphyrin array arranged in a dendritic scaffold...

The design of dendritic multiporphyrin systems [18] permits energy transfer over longer distances. The outer shell of the dendrimer shown in Fig. 5.14 is made up of eight porphyrin-zinc complexes as energy donor units. Excitation of the units of the outer shell leads to fluorescence emission of the metal-free porphyrin core as a result of energy transfer from the periphery to the energy acceptor [19]. 

In another system, the approach is slightly changed in a way that the porphyrin oligomers (dendrons) contain pyridine units for coordination to ruthenium(II) porphyrin monomer building blocks [30]. The dendrons readily form a mono-coordinated complex with the ruthenium(II) porphyrin. After irradiation, the CO ligand is lost, and a second unit can bind to form the dendritic multiporphyrin array 43 (Fig. 32b), where a total of seven porphyrins are assembled. 

Chart 1.5 Chemical structure of a dendritic multiporphyrin array consisting of four wedges of a Zn porphyrin heptamer anchored to a Zn-free porphyrin focal core [22]. 

S. J. Sanders, J.K.M. A combined covalent and coordination approach to dendritic multiporphyrin arrays based on ruthenium(II) porphyrins. New J. Chem. 1999, 23, 359. 

Choi, M.-S., T. Aida, H. Luo, Y. Araki, and O. Ito (2003). Fullerene-terminated dendritic multiporphyrin arrays Dendrimer effects on photoinduced charge separation. Angew Chem. Int. Ed. 42(34), 4060-4063. 

Choi M-S, Aida T, Yamazaki T, Yamazaki I (2001) A large dendritic multiporphyrin array as a mimic of the bacterial light-harvesting anterma complex molecular design of an efficient energy funnel for visible photons. Angew Chem Int Ed 40 3194... 

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