Studies On The Reaction Of Fullerenes With Ester Compounds

Fullerenes can be functionalized through chemical reactions to regulate their properties.Since the discovery of fullerenes,a large number of studies on the chemical properties of fullerenes have been carried out,and many novel fullerene derivatives have been synthesized.The fullerene derivatives have shown attractive prospects in biomedicine,organic electronics,cosmetics,optical materials and superconductors.Both theoretical and electrochemical results show that the properties of fullerene are similar to that of a conjugated polyene.C60 and C70 are favorable for the reactions of nucleophilic addition,radical addition,cycloaddition and so on.The nucleophilic addition is regarded as the most promising protocol for functionalizing fullerene.The derivatives of C60 is easy to be separated and analyzed because of its high symmetry;due to the low symmetry of D5h,the addition reactions of C70 involve both site-and regio-selectivity,so it leads to the formation of a mixture of isomeric products in functionalization reactions and the problem of this regioselectivity limits the development and application of C70 derivatives.To extend the scope of fullerene chemistry and obtain more novel fullerene derivatives with promising properties,this thesis focuses on the reaction of fullerenes and 2-alkylmalonates compounds under basic condition.Not only the reaction mechanism was discussed,but also the differences of thermal stability and solubility of several isomers were studied.The main points are as follows:1.1,16-[60]fullerene derivatives were synthesized with improved efficiency by the reaction of C6o with 2-alkylmalonates in the presence of iodine under mild conditions.The structures of the products were determined by X-ray single-crystal diffractions and spectroscopic characterizations.The reaction mechanism was studied by in situ Vis-NIR.In this reaction,the result indicates that the unique stability of the singly bonded alkylmalonate C60 anionic intermediate(RC60-)without further reaction with the malonate anion is critical for the improved synthesis of the 1,16-C60 adducts.The obtained 1,16-adducts exhibited good thermal stability and better solubility in toluene with respect to the 1,4-isomers,which are essential for the applications of fullerene derivatives.2.Compared to the site-isomers,work on the regioisomers of C70 derivatives is more challenging due to the subtle difference between these isomers.Two types of regioisomeric ?-[70]fullerene-fused lactones were synthesized from the reactions of C70 with 2-alkylmalonates under basic conditions.Two types of regioisoisomeric ?-C70 lactones were characterized by the X-ray single crystal diffraction analysis and spectroscopic methods.The thermal stability and solubility in toluene and o-dichlorobenzene of the two isomers were investigated for the first time.The experimental results showed that they had similar thermal stability and larger solubility difference.