Hydrogenation And Alkylation Of Nano-Graphene Molecules (C₆₀H₂₂ And C₉₆H₃₀)

Graphene is considered one of the most promising materials due to its unique properties.However,the original graphene itself is a semi-metal with a zero band gap,which is not conducive to its application in functional electronic devices.Therefore,it is particularly important to find ways to improve these shortcomings.Covalent functionalization is a common method.However,graphene exhibits huge molecular weight and inactive chemical reactivity.Due to the lack of direct characterization technique,it is almost impossible to obtain a product with a defined structure.In this paper,nano-graphene molecules were used as model compounds to investigate the covalental functionalization of graphene.The main contents of this study are as follows:(1)We synthesized nano-graphene molecules C60H22 and C96H30,respectively,with a typical graphene structure.It can be used as a molecular model to study the mechanism and selectivity of graphene functionalization reaction.In addition,in order to increase the solubility of these two graphene molecules,we also synthesized the mesitylene derivatives of nanographene C60-4mes and C96-6mes.They could be used as starting materials to study the effect of peripheral functional groups on the functionalization of graphene.The product were characterized by means of mass spectrometry,nuclear magnetic resonance spectrometry and spectroscopy.(2)Hydrogenation reaction of nano-graphene molecules with definite structures(such as C60H22 and C96H30)and their derivatives were performed in liquid phase(alkali metal/liquid ammonia conditions)and solid phase(alkali metal/ball milling conditions).The products were separated by silica gel column chromatography and high performance liquid chromatography(HPLC),and characterized by mass spectrometry,infrared and thermogravimetric analysis.Finally,combined with theoretical calculations,the regioselectivity of nanographene molecular hydrogenation were explored providing experimental and theoretical basis for the controlled hydrogenation of graphene.(3)The alkylation reaction under electrochemical conditions of fullerene C60(f-C60),nano-graphene molecule C96H30(g-C96)and its mesitylene derivative C96-6mes were studied in this chapter.By electrochemical reduction or oxidation,alkylation derivatives of fullerene C60 or nano-graphene molecules were obtained in one-step.The products were characterized by mass spectrometry.We explored the feasibility of this electrochemical approach for the controllable alkylation of fullerene and nano-graphene molecules,which could provide an experimental basis for the subsequent controlled alkylation of graphene.