Molecular interactions on single-walled carbon nanotubes revealed by high-resolution transmission microscopy

Abstract

The close solid-state structure–property relationships of organic π−aromatic molecules have attracted interest due to their implications for the design of organic functional materials. In particular, a dimeric structure, that is, a unit consisting of two molecules, is required for precisely evaluating intermolecular interactions. Here, we show that the sidewall of a single-walled carbon nanotube (SWNT) represents a unique molecular dimer platform that can be directly visualized using high-resolution transmission electron microscopy. Pyrene is chosen as the π−aromatic molecule; its dimer is covalently linked to the SWNT sidewalls by aryl addition. Reflecting the orientation and separation of the two molecules, the pyrene dimer on the SWNT exhibits characteristic optical and photophysical properties. The methodology discussed here—form and probe molecular dimers—is highly promising for the creation of unique models and provides indispensable and fundamental information regarding molecular interactions.

Reductive diazotation of carbon nanotubes: an experimental and theoretical selectivity study

“…The binding energies ( E b ) obtained do not depend on the nanotube diameter but rather on the chirality type. This is similar to the results obtained by Umeyama et al 47 for the attachment of a single 4-(1-pyrenyl)phenyl radical on the SWCNTs sidewalls of various chiralities. Furthermore, it has been shown46 that if the diazonium salt anion (BF 4 – ) is included in the calculations, there is a large preference for PhN 2 + to associate with it, instead of being deposited on the surface of the carbon nanotube.…”

Photoinduced electron transfer processes of single-wall carbon nanotube (SWCNT)–based hybrids

“…P2-Pt/SWCNT shows remarkably different photophysical properties compared to the pure P2-Pt polymer (Figure 7c). By comparing the UV-Vis spectra of P2-Pt/SWCNT with the TA spectrum of P2-Pt/ SWCNT at 1 ps (Figure 7d), the bleaching bands at 500 and 670 nm are assigned to the ground state bleaching of the SWCNTs, while the positive bands at 590 and 730 nm represent the formation of the SWCNT singlet excited states [67]. Global analysis of the transient decay dynamics reveals four time constants (Figure 7d): 0.6 ps (62%), 16.3 ps (30%), 408 ps (8%) and a fourth one that exceeds the limitation (>3 ns) of the instrument coverage.…”

Phosphaviologen‐Based Pyrene‐Carbon Nanotube Composites for Stable Battery Electrodes

“…It is well established that pyrene strongly interacts with SWCNTs through π‐stacking, which we can take advantage of in two ways: i) the pyrene‐SWCNTs interactions will prevent phosphaviologen from dissolving into the electrolyte and ii) directly coupling the electroactive species to the conductive additive may also improve electron transfer. Combined, the phosphaviologen core with pendant pyrene groups ( PY 2 PV ) is a small molecule that can act as a multiple‐electron acceptor with high voltage to Li/Li + and can be composited with highly insoluble but electrically conducting SWCNTs.…”