Guldi (University of Erlangen, Germany) supports the notion that a dark charge-transfer state in SWNT/TCAQ nanotweezers transforms upon photoexcitation into a fully charge-separated state.When SWNTs are doubly functionalizated with an imidazolium cation-based ionic liquid, in addition to the TCAQ units, the solubility of the nanomaterial can be adjusted to different media through counteranion exchange. 7 A state of the art photophysical investigation, carried out in collaboration with the group of Prof.

Turning to n-type building blocks, tweezer-shaped 11,11,12,12-tetracyano-9,10-anthraquinodimethane (TCAQ) molecules formed exceptionally stable n-/ p-type dispersions with SWNTs in aqueous media. 5īesides the covalent and non-covalent modification of SWNTs to attain specific electronic properties, SWNTs can form mechanically interlocked species.6 In the key rotaxane-forming step, we employed macrocycle precursors equipped with two π-extended tetrathiafulvalene SWNT recognition units and terminated with bisalkenes that were closed around the nanotubes through ring-closing metathesis (RCM).ĮxTTF-based nanotweezer hybrids and mechanically interlocked SWNTs. We accomplished the solubilization of HiPco and CoMoCAT SWNTs in water, considering dendronized molecules endowed with exTTF moieties (see Figure below). For this purpose, we have prepared pyrene-exTTF 3 or pyrene-TTF 4 derivatives and investigated their electron donor-acceptor interactions with different types of CNTs in organic solvents. 2 Important differences in the grafting density were noticed by thermogravimetric analysis (TGA) measurements, with a significantly higher degree of functionalization for SWNTs (26%) when compared to MWNTs (8%).Īlthough the covalent approach is very versatile, an alternative strategy to control the organization between donor and acceptor units, while preserving the p system of the graphene sheets and, therefore, the electronic structure of CNTs, consists in the supramolecular funtionalization of SWNTs by means of hydrophobic, π-stacking, or van der Waals interactions with the sidewalls of SWNTs. The differences between SWNTs, MWNTs and graphene have been investigated through a combination of arylation and click chemistry CuI-mediated azide–alkyne cycloaddition (CuAAC) reactions. 1Īt the fundamental level, the chemical reactivity of sp 2-hybridized carbons is affected by the curvature and for CNTs exists a direct correlation between the tube diameter and reactivity. Results from near-infrarred and transient absorption measurements showed that the charge recombination dynamics is a function of the spacer linking the TTF moiety to the nanotube and the donor ability of the different TTF derivatives investigated. In a first approach, we prepared single-walled carbon nanotubes (SWNT) endowed with covalently linked tetrathiafulvalene (TTF) derivatives by using simple esterification reactions.

SWNTs-exTTF covalent and non-covalent nanostructures. With the long term objective of constructing versatile and functional nanosized ensembles for photoinduced electron transfer, we embarked on the preparation of donor-acceptor nanohybrids considering the combination of carbon nanotubes with TTF-based p-type building blocks following different, covalent and non-covalent methodologies. Since their discovery, carbon nanotubes (CNTs) are among the materials of choice for applications in nanotechnology due to the excellent characteristics that present: chemical stability, high-quality mechanical properties, high surface area and thermal conductivity. Carbon Nanotubes: Chemical Reactivity and Properties

Reactivity of carbon