Method for selectively preparing different cyclic fullerene derivatives in iodine-alkali system

Abstract

The invention discloses a method for selectively preparing different cyclic fullerene derivatives in an iodine-alkali system. According to the method, selective preparation for methylene bridged fullerene derivative and dihydrofuran cycle-bound fullerene derivative can be realized by regulating and controlling the time of iodine adding; at the beginning of reaction of the two derivatives, an active methylene carbon anion is formed by depriving hydrogen from active methylene in acyloxy carboxylic ester by alkali; selectivity is achieved due to different time of iodine adding during the reactionprocess of the two derivatives; a first process is the active methylene iodination reaction under the existence of abundant iodine in the system; a second process is the preparation of C60 anion containing substituent group by only attacking C60 by the formed active methylene carbon anion due to no iodine existing in the system at first. The method disclosed by the invention has the advantages ofhigh conversion rate of target products, almost no by-products, no heavy metal catalyst, mild reaction conditions, easiness in operation and simple separation and purification steps.

Description

technical field [0001] The invention relates to the field of preparation methods of fullerene derivatives, in particular to a method for selectively preparing methylene bridged and dihydrofuran ring-fused fullerene derivatives. Background technique [0002] Fullerene and its derivatives have important application value in the fields of functional polymer materials, optical materials, solar cells, and biomedical active materials. For example, the unique three-dimensional delocalized π-electron system of fullerene molecules makes it have stronger optical and nonlinear optical effects than other planar π-electron conjugated molecules (Dai, Y.; Li, Z.; Yang, J.J. Phys .Chem.C 2014,118,3313.), which is of great value to the research and development of new nonlinear materials. Fullerenes have excellent ability to accept and transport electrons, so fullerenes and their derivatives can be used as electron acceptor materials for solar cells, which is of great significance in the dev...

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Problems solved by technology

[0005] However, the above-mentioned method in the prior art has the problem of using oxygen or air as a quenching agent to easily cause an increase in toluene insolubles and a decrease in yield; and, so far in the same system, selectivity has been achieved by regulating the addition of the quenching agent Synthesis of two different cyclic fullerene derivatives has not been reported

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