Functionalization of Single-Walled Carbon Nanotubes with (R-)Oxycarbonyl Nitrenes

Abstract

Sidewall functionalization of single-walled carbon nanotubes (SWCNTs) via the addition of (R-)oxycarbonyl nitrenes allows for the covalent binding of a variety of different groups such as alkyl chains, aromatic groups, dendrimers, crown ethers, and oligoethylene glycol units. Such additions lead to a considerable increase in the solubility in organic solvents such as 1,1,2,2-tetrachloroethane (TCE), dimethyl sulfoxide (DMSO), and 1,2-dichlorobenzene (ODCB). The highest solubilities of 1.2 mg/mL were found for SWCNT adducts with nitrenes containing crown ether of oligoethylene glycol moieties in DMSO and TCE, respectively. The presence of chelating donor groups within the addends allowed for the complexation of Cu(2+) and Cd(2+). Atomic force microscopy (AFM) and transmission electron microscopy (TEM) revealed that the functionalized tubes form thin bundles with typical diameters of 10 nm. The presence of thin bundles in solution is supported by (1)H NMR spectroscopy. The elemental composition of the functionalized SWCNT was determined by X-ray photoelectron spectroscopy (XPS). The use of Raman and electron absorption spectroscopy (UV/Vis-nIR) showed that the electronic properties of the SWCNTs are mostly retained after functionalization, indicating a low degree of addition within this series of SWCNT derivatives.

Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes

“…However, a reduction in the intensity of the BWF component was also observed upon acid treatments using HNO 3 or H 2 SO 4 air oxidation, 94,158,159 defect group functionalization, 160 and covalent sidewall functionalization using nitrenes. 161 Interestingly, the effect upon acid treatment is found to be reversible if the samples are annealed, and the effect of H 2 SO 4 is more pronounced than that of HNO 3 . 158,159 This points to an effect of doping, as sulfuric acid is a stronger dopant than nitric acid.…”

Covalently Functionalized Hexagonal Boron Nitride Nanosheets by Nitrene Addition

“…Previously, nitrene addition has been used to covalently functionalize graphene and CNTs via the formation of aziridine ring species. 10,13 Even though BN allotropes are known to exhibit excellent chemical stability in strongly acidic and basic conditions, 14 it might be expected that the generation of a highly reactive nitrene species in the presence of exfoliated h-BN could result in covalent functionalization of the h-BN sheet.…”

p-Type Doping of Epitaxial Graphene by p-tert-Butylcalix[4]arene

“…2(a), three distinct peaks emerged at 285.5, 284.8, and 283.6 eV, which were assigned, respectively, to sp 2 carbon atoms in the interface layer weakly interacting with the carbon atoms of the underlying substrate (marked as S2), carbon atoms in the interface layer bound to one Si and three C atoms in the underlying substrate (marked as S1), and SiC (marked as SiC). 20,21 After confirming the pristine state of the monolayer graphene by C 1s core-level spectroscopy, we exposed the EG to 4000 L p-tert-butylcalix [4]arene. Figure 2(b) shows the C 1s core-level spectrum after the adsorption of ptert-butylcalix [4]arene (4000 L) on EG, during which the substrate temperature was maintained at 100 o C to enhance the adsorption rate.…”