Functional Modification Of Hydrogenated Fullerene Sp~3C-H

From the beginning of the “fullerene era”,an obvious challenge to chemists was to hydrogenate fullerenes.Indeed,hydrogenations of C60 were the first reported attempts to chemical modification of fullerene.However,this project was proved to be very difficult.Researchers spent a long time to achieve structural characterization of some hydrogenated fullerenes structure.The selective functionalization of the fullerene sp³C-H has been a difficult problem.The fullerene anions were generally obtained by the deprotonation of hydrogenated fullerene and then alkylated reaction.This is a process from electrophilic to nucleophilic,which is not directly obtainable by current methods.This work mainly explored the selective functionalization of sp³C-H on fullerene by using C₆₀H₂ as substrate,palladium acetate as catalyst,o-chloranil as oxidant,and three kinds of C60 derivatives were synthesized.The details are as follows:?1?According to the similar literature about activation of sp³ C-H bond,the reactions of C₆₀H₂,such as aromatization,boronization,diethyl malonate and C-O coupling,were investigated by using C₆₀H₂ as the substrate.And the results were analyzed through the nuclear magnetic resonance?NRM?,high performance liquid chromatography?HPLC?and liquid phase-mass spectrometry?HPLC-MS?,and the reasons for the success and failure of the experiment were summarized.?2?The sp³C-H on the fullerene was selectively modified by using C₆₀H₂ as the substrate,benzene solvent as the benzene source,palladium acetate as catalyst,o-chloranil as oxidizing agent.The crude product was separated by silica gel column chromatography,and further purified by HPLC.The target molecule C60 PhH was characterized by MS,1HNMR,13 CNMR and UV-Vis.Meanwhile,for rigorous scientific research,a series of deuterium labeling experiments were performed to synthesize C60D2 and C60 PhD successively.By comparing 1H NMR of C60D2 with C₆₀H₂,C60 PhD with C60 PhH,we concluded that the proposed method hasregioselectivity.?3?According to the synthesis of C60C6H4 ClH,C60CCSi?CH?3H,C60CCH3 H and C60CH3 H,we researched the synthetic methods to the selectivity of sp³C-H on other fullerene derivatives,which is to optimize the reaction conditions,reduce the production of by-products of C60 and improve the yield.Finally,C60CH3 Ph was obtained by using the C60CH3 H as the substrate,benzene as the solvent,palladium acetate as catalyst and o-chloranil as oxidant.Then the crude product was separated and purified by silica gel column chromatography and HPLC respectively.The pure C60CH3 Ph was characterized by MS,1HNMR and UV-Vis.?4?1,2-H?PhCH2?C₆0 was synthesized by using C₆₀H₂ as the substrate,toluene as solvent,palladium acetate as catalyst,and o-chloranil as oxidant.Then the crude product was separated and purified by silica gel column chromatography and HPLC respectively.The structure of pure 1,2-H?PhCH2?C60 was characterized by HPLC-MS and1 HNMR.