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Eco-Friendly 1,3-Dipolar Cycloaddition Reactions on Graphene Quantum Dots in Natural Deep Eutectic Solvent
Salvatore V Giofrè1, Matteo Tiecco2, Consuelo Celesti3
1Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, I-98168 Messina, Italy.
Nanomaterials (Basel, Switzerland)
|December 23, 2020
Summary
Graphene quantum dots (GQDs) underwent 1,3-dipolar cycloaddition reactions using eco-friendly deep eutectic solvents. This study demonstrates the first successful cycloaddition directly onto the GQD p-cloud surface.
Area of Science:
- Nanotechnology
- Materials Science
- Organic Chemistry
Background:
- Graphene quantum dots (GQDs) possess unique physicochemical properties, positioning them at the forefront of nanotechnology.
- Hydrophilic functionalities on GQDs aid water dispersibility but can hinder reactions in organic solvents, such as cycloadditions.
- 1,3-dipolar cycloaddition (1,3-DCA) is a key reaction for synthesizing heterocyclic compounds.
Purpose of the Study:
- To investigate the 1,3-dipolar cycloaddition (1,3-DCA) reactions between nitrones and graphene quantum dots (GQDs).
- To explore the use of natural deep eutectic solvents (NADES) as mild and eco-friendly reaction media for GQD functionalization.
- To demonstrate the feasibility of performing cycloaddition reactions directly on the p-cloud of GQDs.
Main Methods:
- Utilized two nitrones: C-ethoxycarbonyl N-methyl nitrone (1a) and C-diethoxyphosphorylpropilidene N-benzyl nitrone (1b).
- Employed a specific NADES composed of trimethylglycine and glycolic acid, free of chloride or metal ions.
- Performed reactions under mild conditions, facilitating the formation of isoxazolidine cycloadducts (isox-GQDs 2a and 2b).
Main Results:
- Successfully achieved 1,3-DCA reactions between nitrones and the surface of GQDs, yielding isoxazolidine cycloadducts.
- Demonstrated the first instance of cycloaddition reactions occurring directly on the p-cloud of the GQD surface.
- Highlighted the advantages of using deep eutectic solvents (DES), including enhanced reactant solubility and strong affinity for aromatic systems.
Conclusions:
- Cycloaddition reactions can be effectively performed directly on the p-cloud of graphene quantum dots.
- Natural deep eutectic solvents offer a green, efficient, and advantageous medium for GQD functionalization via cycloaddition.
- This work opens new avenues for modifying GQDs for advanced nanotechnology applications.
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