Carbon Nanotubes Conjugated with Triazole‐Based Tetrathiafulvalene‐Type Receptors for C₆₀ Recognition

Abstract

Fullerene receptors prepared by a twofold CuI‐catalyzed azide‐alkyne cycloaddition reaction with π‐extended tetrathiafulvalene (exTTF) have been covalently linked to single‐walled carbon nanotubes and multi‐walled carbon nanotubes. The nanoconjugates obtained were characterized by several analytical, spectroscopic and microscopic techniques (TEM, FTIR, Raman, TGA and XPS), and evaluated as C60 receptors by using UV‐Vis spectroscopy. The complexation between the exTTF‐triazole receptor in the free state and C60 was also studied by UV‐Vis and 1H NMR titrations, and compared with analogous triazole‐based tweezer‐type receptors containing the electron‐acceptor 11,11,12,12‐tetracyano‐9,10‐anthraquinodimethane and benzene rings instead of exTTF motifs, providing in all cases very similar values for the association constant (log Ka≈3.0−3.1). Theoretical density functional theory calculations demonstrated that the enhanced interaction between the host and the guest upon increasing the size of the π‐conjugated arms of the tweezer is compensated by an increase in the energy penalty needed to distort the geometry of the host to wrap C60.

Recent advances in supramolecular fullerene chemistry

“…By binding C 60 relatively strongly (log K a ≈ 3.0–3.1), interesting non-covalent C 60 /CNT hybrid materials can be obtained. 170 …”

“…By binding C 60 relatively strongly (log K a E 3.0-3.1), interesting non-covalent C 60 /CNT hybrid materials can be obtained. 170 Corannulene is a bowl-shaped polycyclic aromatic hydrocarbon (PAH), which is predisposed for the binding fullerenes, because it represents a fragment of C 60 . In recent years, several p-extended and N-embedded ''buckybowls'' have been synthesized.…”