Finely designed arrangements and photoelectronic properties of supramolecular nanocarbons composed of fullerenes and cyclic porphyrin dimers

We have studied the supramolecular structures and photoelectronic properties of inclusion complexes of cyclic porphyrin dimers (M2-CPDPy, M = Ni, 2H) and fullerenes (C60, C70, PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) and Li+@C60). The porphyrin dimers have self-assembling 4-pyridyl groups at the meso positions and include fullerenes in their cavities with high affinities (Kassoc ≈ 105M−1). In crystals, C60 ⊂ Ni2-CPDPy and PCBM ⊂ Ni2-CPDPy give self-assembled porphyrin nanotubes containing the linear arrays of fullerene molecules. These self-assemblies are induced mainly by the non-classical hydrogen bonds between pyridyl nitrogens and porphyin β C–H groups. On the other hand, in the crystals of C60 ⊂ H4-CPDPy and C70 ⊂ H4-CPDPy, the included fullerene molecules show zigzag chains through van der Waals contacts with each other. Due to these well-ordered arrays of C60, both crystals of C60⊂ Ni2-CPDPy and C60 ⊂ H4-CPDPy have high charge mobilities (Σμ > 0.1 cm2 V−1 s−1). C60 ⊂ H4-CPDPy shows photoinduced electron transfer from the porphyrin moieties to C60 and photovoltaic activity with IPCEmax = 17% in photoelectrochemical cells. Moreover, the inclusion complexes of lithium-ion-encapsulated C60(Li+@C60) and M2-CPDPy exhibit photoinduced charge separation with very long lifetimes reaching submillisecond order. [TANSO 2013 (No. 260) 284–91.]