Covalent Functionalization of Single-Walled Carbon Nanotubes by the Bingel Reaction for Building Charge-Transfer Complexes

How Do Defects in Carbon Nanostructures Regulate the Photoinduced Electron Transfer Processes? The Case of Phenine Nanotubes

Photoinduced electron transfer is studied in a series of inclusion complexes of structurally modified phenine nanotubes (pNT) with C70 using the TD-DFT method. Analysis of electronic properties of the complexes shows that the electron transfer is infeasible in pNT_4d⊃C70 built on the tetrameric array of [6]cyclo-meta-phenylene ([6]CMP) units. However, replacing one or more [6]CMP units with a coronene moiety enables electron transfer from pNT to C70 . The generation of the charge separated states from the lowest locally excited states occurs on a sub-nanosecond time scale. Depending on the number of the [6]CMP units, the charge recombination rate varies from 1.8 ⋅ 107 to 3.1 ⋅ 102  s-1 , i. e., five orders of magnitude.

Switchable (2 + 2) and (4 + 2) Cycloadditions on Boron Nitride Nanotubes under Oriented External Electric Fields: A Mechanistic Study

The (2 + 2) and (4 + 2) cycloadditions are important approaches for the functional derivatizations of nanocarbon and hexagonal boron nitride (hBN) materials. However, as two competing reactions with similar reactivity, it is difficult to control the type of reactions and the corresponding adducts in practice. Here, we introduced a mechanistic study of the oriented external electric field (OEEF)-modulated cycloadditions of pristine and substituted benzynes on the zigzag boron nitride nanotubes. Owing to the distinct charge transfer directions between the competing (2 + 2) and (4 + 2) reactions and the resultant distinct responses of the barriers to the fields along the tube axis, we found that OEEF plays opposing catalytic roles in these two types of reactions and the effect of electric field as a catalyst or inhibitor can be easily reversed by flipping the field vector to achieve selective reactions and products at will.

Photoinduced electron transfer in nano-Saturn complexes of fullerene

The photoinduced electron transfer is studied computationally in several Saturn-shaped inclusion complexes of carbo-aromatic rings and C60 fullerene - C72⊃C60, C96⊃C60, C120⊃C60, and C168⊃C60. Analysis of their structural and electronic properties shows that the charge separation process is efficient in C120⊃C60 and C168⊃C60 where the host molecule resembles the conjugated [24]circulene unit. In contrast, the electron transfer is not feasible in the complexes of the oligophenylene-based rings C72⊃C60 and C96⊃C60.