Synthesis,efficient Purification And Functionalization Of Metallofullerene Sc₃N@I_h-C₈₀

Endohedral metallofullerenes（EMFs）are novel molecules,in which atoms,atomic clusters,ions are trapped into the cavity of carbon cage.Compared with the empty cage fullerenes,the interaction between entrapped species and cage in EMFs makes them possess more special properties.In order to get in-depth understanding and control the physicochemical properties,a series of reactions were employed to get corresponding fullerene derivatives.However,the present research focuses on derivatizations of EMFs neutral molecules,while the research on ionization lags behind.In this thesis,synthesis,purification and functionalization of Sc₃N@I_h-C₈₀have been systematically studied,including the following three parts:Synthesis and purification of Sc₃N@I_h-C₈₀:Arc-discharging method were used in the preparation of Sc₃N@I_h-C₈₀and the fullerenes in soot were extracted by soxhlet extraction method.By introducing Ti Cl₄,a Lewis acid with high selectivity of EMFs,the separation is rather effective to separate Sc-based EMFs from empty fullerene,which simplify the subsequent HPLC separation.Due to the inefficiency of the HPLC method,an efficient method based on the different oxidation potentials between the Sc₃N@C₈₀I_hand D_5hisomers was applied to separate both isomers,which can support the properties study.The synthesis of novel frameworks such as those incorporating four-membered rings is likely to bring new developments to the field.Construction of Sc₃N@I_h-C₈₀four-member ring:design and synthetsis of dimethyl1,2,4,5-tetrazine-3,6-dicarboxylate.Through optimization,derivative A with high purity was obtained with HPLC equipping with Buckyprep and 5PBB column.The molecular structure of A was measured through MALDA-TOF mass spectrometry and ¹H NMR characterization.The results show the derivative maybe have a four-member ring.This conclusion should be confirmed by subsequent single crystal X-ray diffraction crystallography.Functionalization of[Sc₃N@I_h-C₈₀]⁺cation:we conducted both the electrochemical and chemical oxidation of Sc₃N@I_h-C₈₀to generate[Sc₃N@I_h-C₈₀]⁺cations.Controlled potential electrolysis（CPE）method and oxidant tris（para-bromophenyl）aminium hexachloroantimonate（TPBAH）were employed respectively.Under 1,3-dipolar conditions,[Sc₃N@I_h-C₈₀]⁺cation shows higher reactivity toward nucleophiles comparing to the neutral Sc₃N@I_h-C₈₀.High-purity derivatives F1 and F3 were separated with HPLC equipping with Buckyprep and 5PBB column.According to MALDA-TOF mass spectrometry and ¹H NMR result,we speculate the two derivatives are isomeric,[5,6]product and[6,6]products.This study promote a better understanding of EMFs cations and offer a complementary strategy to activate and functionalize EMFs.