Synthesis And Properties Of Metallofullerene Gd@C₈₂ Derivatives

Many researches have been focused on Gd@C₈₂ due to its application in nuclear magnetic contrast agents and anticancer drugs.However,there are two major challegnes in the study of metallofullerenes.First,the preparation and separation of metallofullerenes are complicated and it is difficult to achieve macro-preparation.On the other hand,due to a large number of reactive sites on the carbon cage,the types of products generated during the derivatization of fullerenes are complex.This article focuses on the macro-preparation of Gd@C₈₂ and the selective synthesis of its derivatives,including the following three parts:Optimization of the synthesis and separation process of metallofullerene Gd@C₈₂:Arc discharge method were used in the macro-preparation of metallofullerenes with GdNi alloy and graphite powder mixed carbon rod?alloy and graphite ratio 12:1?as cathode.The highest content of Gd@C₈₂ in the soot was obtained when current intensity was 140 A and helium gas pressure was 600 Torr,respectively.Gd@C₈₂ is effectively purified by oxidation using TiCl4.Then,Gd@C₈₂ with high purity was obtained using Buckyprep and Buckyprep-M columns,which supported its properties study.Reaction research between Gd@C₈₂2 and 3-?2-pyridyl?-5,6-diphenyl-1,2,4-triazine:Through optimization,High-purity Gd@C₈₂ triazine monoaddition derivatives K1 and K2were obtained.MALDI-TOF MS spectra,HPLC separation spectra,UV-vis-NIR absorptions and electrochemical properties display their structures,that is,K1,K2 are chiral isomers of mono-adducts.In addition,electron spin resonance spectrum?ESR?simulations show that the g-factors of the main products K1 and K2 are very close,2.0157and 2.0159,respectively.And,the deviations of the magnetic energy levels of the derivatives in the axial symmetry?D value?and the spherical symmetry?E value?are the same,reflecting that the electron cloud offsets of the derivatives K1 and K2 molecules are the same.It is further illustrated that the main product derivatives K1 and K2 have the same addition sites.Combined negative Strain and local tension?POVA?of Gd@C_82,the structure of K1 and K2 were determined.K1 and K2 are chiral isomers of mono-adducts on C1 and C2.Researches in reactions between Gd@C₈₂ and 1,2,4,5-tetrazine:Two kinds of tetrazine were chose as the reactants.When Gd@C₈₂ reacted with 3,6-di-2-pyridine-1,2,4,5-tetrazine,a monoaddition hydroxylation derivatives D weas obtained.While,Gd@C₈₂ reacting with 3,6-diphenyl-1,2,4,5-tetrazine obtained a monoaddition derivative E.The optimal reaction conditions for the reaction of Gd@C₈₂with two tetrazine molecules were determined.At the same time,the characteristic signals of derivative D and E in HPLC,UV-Vis-NIR absorption and ESR spectra are significantly different,indicating that derivative D and E have different structures.In the spin Hamiltonian parameters derived from the ESR simulation,the g factors of derivatives D and E are 2.0203 and 2.0157,respectively.It is found that the axial and inner symmetry magnetic energy level of D is less than E.This is because the presence of the hydroxyl group in D reduces the migration of the electron cloud of metal Gd.Combined negative Strain and local tension?POVA?of Gd@C_82,the structure of D has been determined to be S,and E to be T.In perovskite solar cell research,derivative D perovskite solar cells have the best performance.Its open circuit voltage Voc is 0.83V,and total efficiency PCE has reached 4.23%.This study provides a theoretical basis for broadening the performance of Gd@C₈₂ derivatives in perovskite solar cells.