Departamento de Química-Física, Laboratorio de Química Teórica Computacional (QTC), Facultad de Química, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile.
Instituto de Química del Sur (INQUISUR), CONICET-UNS, Universidad Nacional del Sur, Av. Alem 1253, 8000, Bahía Blanca, Argentina.
J Mol Model. 2020 Jan 25;26(2):33. doi: 10.1007/s00894-020-4297-8.
The non-dissociative and dissociative adsorptions of zwitterionic Gly on graphene oxide (GO) was studied in the framework of DFT using a cluster model approach. In this work, the interaction with an epoxy group of GO basal plane was mainly considered. As a comparison, the non-dissociative and dissociative adsorptions of neutral Gly were also taken into account. The non-dissociative adsorption modes for zwitterionic and neutral Gly conformers show binding energies of 12.2 and 14.4 kcal mol, respectively. These molecules are thought to remain over the GO surface due to attractive noncovalent interactions. Two dissociative adsorption modes, for Z-Gly and N-Gly, show smaller binding energies of 7.2 and 8.4 kcal mol, where the deprotonated species links strongly through a C-O or C-N covalent bond to the GO surface. The results obtained in the present theoretical approach to the glycine/graphene oxide system support the fact that glycine can be attached to epoxy groups of graphene oxide basal planes in addition to the anchoring on edge oxidation groups. In summary, we conclude that glycine can be used as a reducing agent as well as a functionalizer of GO sheets.
在 DFT 框架下，使用团簇模型方法研究了两性离子甘氨酸在氧化石墨烯（GO）上的非解离和解离吸附。在这项工作中，主要考虑了 GO 基面与环氧基团的相互作用。作为比较，还考虑了中性甘氨酸的非解离和解离吸附。两性离子和中性甘氨酸构象体的非解离吸附模式的结合能分别为 12.2 和 14.4 kcal/mol。由于存在吸引力的非共价相互作用，这些分子被认为仍然位于 GO 表面上。对于 Z-Gly 和 N-Gly，有两种解离吸附模式，其结合能分别为 7.2 和 8.4 kcal/mol，其中去质子化的物种通过 C-O 或 C-N 共价键与 GO 表面强烈连接。本研究中对甘氨酸/氧化石墨烯体系的理论方法的结果支持了这样一个事实，即甘氨酸可以除了通过与边缘氧化基团的锚固作用之外，还可以附着在氧化石墨烯基面的环氧基团上。总之，我们得出结论，甘氨酸可以用作 GO 片的还原剂和功能化剂。
