Molecular Surface Functionalization of Carbon Materials via Radical-Induced Grafting of Terminal Alkenes

Abstract

Formation of functional monolayers on surfaces of carbon materials is inherently difficult because of the high bond strength of carbon and because common pathways such as SN2 mechanisms cannot take place at surfaces of solid materials. Here, we show that the radical initiators can selectively abstract H atoms from H-terminated carbon surfaces, initiating regioselective grafting of terminal alkenes to surfaces of diamond, glassy carbon, and polymeric carbon dots. Nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) demonstrate formation of self-terminating organic monolayers linked via the terminal C atom of 1-alkenes. Density functional theory (DFT) calculations suggest that this selectivity is at least partially thermodynamic in origin, as significantly less energy is needed to abstract H atoms from carbon surfaces as compared to typical aliphatic compounds. The regioselectivity favoring binding to the terminal C atom of the reactant alkenes arises from steric hindrance encountered in bond formation at the adjacent carbon atom. Our results demonstrate that carbon surface radical chemistry yields a versatile, selective, and scalable approach to monolayer formation on H-terminated carbon surfaces and provide mechanistic insights into the surface selectivity and regioselectivity of molecular grafting.

Recent Advances in Functional Carbon Quantum Dots for Antitumour

“…110 With the kinetic energy/binding energy of photoelectrons as the abscissa and the relative intensity as the ordinate, the photoelectron spectrum can be created to obtain relevant information on the CQDs. 111 As a modern analytical method, XPS has the following characteristics: the ability to analyse all elements except H and He, strong identification, the ability to observe chemical shifts, quantitative analysis and high sensitivity. 112 Figure 6A-C correspond to the survey, C 1s and O 1s XPS spectra of the obtained CQDs, respectively.…”

Influence of MgF2 nanoparticles in the plasma polymer fluorocarbon‐based transparent nanocomposite thin films on the surface hardness properties

“…The peaks in the MgF 2 0 thin film are located at binding energies of 294.0 eV (-CF 3 ), 292.0 eV (-CF 2 -), 289.9 eV (-CF), 288.6 eV (C═C-F), 287.5 eV (C-CF n ), 286.1 eV (C-C), and 285.0 eV (C-C, H). [35][36][37][38] As the MgF 2 concentration increases from 10% to 30% in the MgF 2 -CNT-PTFE composite target, the intensity of the C-C bonds increases, and the intensities of the CF 3 , CF 2 , and CF decrease in the MgF 2 -PPFC nanocomposite thin films (Figure 2b-d). The C-Mg bonds in the XPS analysis of MgF 2 -PPFC thin films are not observed.…”

“…The single peak at 698.2 eV in the F 1s spectrum of the MgF 2 0 thin film without MgF 2 nanoparticle represents the C-F bonds. [35][36][37][38] The F 1s spectra of the MgF 2 10, MgF 2 20, and MgF 2 30 thin films prepared by sputtering composite targets containing MgF 2 show two peaks at 687.2 eV, corresponding to the Mg-F 2 bonds, and 689.2 eV. As the MgF 2 concentration increases in the thin films, the intensity of the Mg-F 2 bonds (687.2 eV) increases, and the intensity of the C-F bonds (689.2 eV) decreases.…”

A Carbonized Fluorescent Nucleolus Probe Discloses RNA Reduction in the Process of Mitophagy

“…13 Recently, carbonized fluorescent probes, such as carbon dots (CDs), have emerged as an important class of fluorescent probes and been widely applied in live cell imaging, due to their excellent biocompatibility, facile preparation and high cell permeability. [14][15][16][17][18][19][20] Additionally, the abundant precursors available for preparing CDs provide advantages in designing fluorescent probes with specific targeting ability. 21 To achieve RNA-specific targeting capability, an ingenious solution is to synthesize CDs with RNA affinity materials.…”