The nucleophilicity of the oxygen functional groups on carbon materials: a DFT analysis

The nucleophilicity of the five different oxygen functional groups (carboxyl, diketone, ketone, lactone, and quinone) on the graphene are evaluated by DFT calculations. Two different methods are employed to obtain three different reactivity descriptors, namely, sk(-), wk(-), and sk(-)/sk(+). The calculations indicate that the quinone group is the most nucleophilic site among the investigated ones. The diketone and ketone are much less active than the quinone group toward an electrophilic attack. This judgment is further supported by Ag(+)-binding calculations, which mimics an electrophilic attack. In addition, the carboxyl and lactone groups at a zigzag-terminated edge show nucleophilic ability that is comparable to that of diketones. The current work lays the basis for future studies on the redox property of carbon catalysis and its implications in catalytic reactions.