Radical Addition of Xanthates on Carbon Nanotubes as an Efficient Covalent Functionalization Method

Abstract

Radical-initiated support: Xanthates were used as chemical reagents for the sidewall covalent functionalization of carbon nanotubes (see figure). The best grafting yields were obtained with stoichiometric ratios of xanthate and the radical initiator lauroyl peroxide. One grafted function was used as a tether for bimetallic cluster compounds, which were converted into very small (1-2 nm) supported nanoparticles upon heating.

Covalently and non-covalently immobilized clusters onto nanocarbons as catalysts precursors for cinnamaldehyde selective hydrogenation

“…The XPS results obtained before and after functionalization are also reported in Table 3. The obtained F/C ratio was in agreement with previously reported values [46], and corresponded to a functionalization degree of 1 function every 22 carbons of the tubes given the average number of concentric tubes in a MWNT observed by TEM, that is approximately 10 (see SI Section 3.1).…”

“…Surface modification of MWNTs through the radical xanthate chemistry. The xanthate 13 (see SI Section 3.3 for experimental) has already been proven reliable [46] and was thus selected to Table 1 Synthesis of adducts 7-12 by reaction between 1 or 2 as bifunctional ligand and 3-6 as cluster.…”

“…When the covalent pathway was undertaken, a pre-functionalization step is required (I): Acyl chloride functions were formed on GO or MWNTs on oxygenated functions located at defects-and end-sites. A recently reported radical approach involving xanthate chemistry applied to MWNTs was also selected to prefunctionalize nanocarbons [46]. In the next step, mono-and multi-metallic clusters were selected as single source metal precursors and immobilized onto nanocarbons by a covalent or a non-covalent strategy (II).…”

Covalent Functionalization of Carbon Nanotubes with Xanthates and Peroxides

“…[28] This ratio has to be equal to one to obtain the highest R grafting yield. [28] This ratio has to be equal to one to obtain the highest R grafting yield.…”

An Atom‐Economical Approach to Functionalized Single‐Walled Carbon Nanotubes: Reaction with Disulfides

“…This finding confirms the results recently reported for the radical addition of xanthates to multiwalled carbon nanotubes and SWCNTs. [15] In conclusion, we have presented a detailed study on a novel, straightforward, fast, and reliable protocol for nanotube functionalization. This new process shows the further advantage of atom economy, since it allows the recovery and reuse of unreacted disulfides.…”