Functionalized carbon nanohorns and fullerene hybrids.
DFT and Time dependent Density Functional Theory calculations have been carried out on nano-hybrids of carbon nanohorns and fullerenes with photo- or electro- active substituents, porphyrin, pyrene, tetrathiafulvalene and others, of interest for photoinduced charge transfer. It is found that the relevant excitations in the individual substituents retain their characteristics in the nanohybrid systems. This is also shown in the electron density plots of the molecular orbitals (Fig.1-Fig. 3). The photoinduced charge-transfer can be often described in terms of simple orbital energy diagrams.
Fig. 1: Electron density plots for the highest occupied and lowest unoccupied orbitals relevant to absorption by the substituent, a and b for TTF, c and d for pyrene.
Fig. 2: Electron density plots for the highest occupied and lowest unoccupied orbitals in the fulleropyrrolidine-porphyrin hybrid
Fig. 3: Electron density plots for the highest occupied and lowest unoccupied orbitals relevant to porphyrin absorption in the CNH-porphyrin hybrid
Fig. 4: Orbital energy levels and excitations relevant to photoinduced charge transfer (D-A) in the C60-pyrene hybrid.
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