Giofrè Salvatore V, Tiecco Matteo, Celesti Consuelo, Patanè Salvatore, Triolo Claudia, Gulino Antonino, Spitaleri Luca, Scalese Silvia, Scuderi Mario, Iannazzo Daniela
Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, I-98168 Messina, Italy.
Department of Chemistry, Biology and Biotechnology, University of Perugia, I-06123 Perugia, Italy.
Nanomaterials (Basel). 2020 Dec 18;10(12):2549. doi: 10.3390/nano10122549.
Due to their outstanding physicochemical properties, the next generation of the graphene family-graphene quantum dots (GQDs)-are at the cutting edge of nanotechnology development. GQDs generally possess many hydrophilic functionalities which allow their dispersibility in water but, on the other hand, could interfere with reactions that are mainly performed in organic solvents, as for cycloaddition reactions. We investigated the 1,3-dipolar cycloaddition (1,3-DCA) reactions of the C-ethoxycarbonyl -methyl nitrone and the newly synthesized -diethoxyphosphorylpropilidene -benzyl nitrone with the surface of GQDs, affording the isoxazolidine cycloadducts -GQDs and -GQDs . Reactions were performed in mild and eco-friendly conditions, through the use of a natural deep eutectic solvent (NADES), free of chloride or any metal ions in its composition, and formed by the zwitterionic trimethylglycine as the -bond acceptor, and glycolic acid as the hydrogen-bond donor. The results reported in this study have for the first time proved the possibility of performing cycloaddition reactions directly to the p-cloud of the GQDs surface. The use of DES for the cycloaddition reactions on GQDs, other than to improve the solubility of reactants, has been shown to bring additional advantages because of the great affinity of these green solvents with aromatic systems.
由于其优异的物理化学性质，石墨烯家族的下一代——石墨烯量子点（GQDs）——处于纳米技术发展的前沿。GQDs通常具有许多亲水性官能团，这使得它们能够分散在水中，但另一方面，可能会干扰主要在有机溶剂中进行的反应，如环加成反应。我们研究了C-乙氧羰基-甲基硝酮与新合成的-二乙氧基磷酰基丙叉基-苄基硝酮与GQDs表面的1,3-偶极环加成（1,3-DCA）反应，得到异恶唑烷环加成产物-GQDs和-GQDs。反应在温和且环保的条件下进行，通过使用一种天然低共熔溶剂（NADES），其组成中不含氯或任何金属离子，由两性离子三甲基甘氨酸作为-键受体和乙醇酸作为氢键供体形成。本研究报道的结果首次证明了直接对GQDs表面的p-云进行环加成反应的可能性。除了提高反应物的溶解度外，将DES用于GQDs上的环加成反应已显示出带来额外的优势，因为这些绿色溶剂与芳香体系具有很强的亲和力。
