Shedding Light on the Chemistry and the Properties of Münchnone Functionalized Graphene

Abstract

Münchnones are mesoionic oxazolium 5-oxides with azomethine ylide characteristics that provide pyrrole derivatives by a 1,3-dipolar cycloaddition (1,3-DC) reaction with acetylenic dipolarophiles. Their reactivity was widely exploited for the synthesis of small molecules, but it was not yet investigated for the functionalization of graphene-based materials. Herein, we report our results on the preparation of münchnone functionalized graphene via cycloaddition reactions, followed by the spontaneous loss of carbon dioxide and its further chemical modification to silver/nisin nanocomposites to confer biological properties. A direct functionalization of graphite flakes into few-layers graphene decorated with pyrrole rings on the layer edge was achieved. The success of functionalization was confirmed by micro-Raman and X-ray photoelectron spectroscopies, scanning transmission electron microscopy, and thermogravimetric analysis. The 1,3-DC reactions of münchnone dipole with graphene have been investigated using density functional theory to model graphene. Finally, we explored the reactivity and the processability of münchnone functionalized graphene to produce enriched nano biomaterials endowed with antimicrobial properties.

Covalent functionalization of 1D and 2D sp2-carbon nanoallotropes – twelve years of progress (2011–2023)

“…Indeed, (3 + 2)-cycloaddition was applied to make FLG-containing pyrrole rings. 183 By using diazonium chemistry, benzene thiol groups were grafted onto münchnone–graphene surfaces to attach Ag-NPs and nisin – an antimicrobial peptide. The synthesis of münchnone-functionalized graphene with nisin@Ag enhanced the overall processability and the resultant G-MuSH/nisin@Ag nanocomposite was evaluated as a potential new antibacterial nanomaterial.…”

Graphene and graphene oxide with anticancer applications: Challenges and future perspectives

“…However, some of these functionalization techniques such as addition may suffer from difficulty in controlling, thus controllable selective strategies should be further explored by researchers. 35 , 36 …”

“…Increased electrical conductivity, enhanced dispersibility, improved functionality, and good biocompatibility have been reported as outstanding benefits of these functionalized materials. However, some of these functionalization techniques such as addition may suffer from difficulty in controlling, thus controllable selective strategies should be further explored by researchers 35,36 …”

“…However, some of these functionalization techniques such as addition may suffer from difficulty in controlling, thus controllable selective strategies should be further explored by researchers. 35,36 For constructing advanced G-based nanosystems for diagnosis and treatment of cancers, several challenging issues should be considered such as flexibility, biocompatibility, biodegradability, toxicity, surface functionizability, and fluorescence quenching potentials. [37][38][39][40][41][42] The surface modification and functionalization of G-based materials can be performed by different polymeric materials.…”