How Does Spin Play with the Cycloaddition to Paramagnetic Endohedral Metallofullerenes? The Curious Case of TiSc2N@C80

DOI码：10.1021/acs.inorgchem.2c02784

所属单位：扬州大学化学化工学院

教研室：物理化学

发表刊物：Inorganic Chemistry

项目来源：国家自然科学基金（22073080）

摘要：Diels−Alder cycloaddition is one of the most important reactions for fullerenes, providing a powerful means for exohedral cage functionalization. When it comes to endohedral metallofullerenes (EMFs), however, it is well accepted that they are much less reactive toward Diels−Alder addition than empty fullerenes because of the charge transfer from the encapsulated metal cluster to the carbon cage. Herein, using density functional theory calculations, we report that the paramagnetic EMF, TiSc2N@C80, exhibits a considerably enhanced reactivity toward the cycloaddition with s-cis-1,3-butadiene (BD), with quite different regioselectivity from that for the empty C80 and Sc3N@C80. Most interestingly, the lowest-barrier pathways follow a [4 + 3]-like stepwise mechanism, in stark contrast with the conventional [4 + 2] concerted mechanism. Such a drastic mechanistic modification can be understood by the fact that the spin on Ti in TiSc2N@C80 transfers to BD upon formation of the intermediate and returns to Ti after forming the cycloadduct. Accordingly, by attaching π-withdrawing substituents to BD, the intermediate can be further stabilized through delocalization of the radical in BD and may thus remarkably improve the addition reactivity. These findings showcased by TiSc2N@C80 might widen our knowledge of how spin could profoundly change the chemical picture of paramagnetic EMFs.

第一作者：孙婧

论文类型：SCI

通讯作者：汪洋

学科门类：理学

一级学科：化学

文献类型：SCI

卷号：61

期号：48

页面范围：19183–19192

是否译文：否

发表时间：2022-11-20

收录刊物：SCI

发布期刊链接：https://pubs.acs.org/doi/abs/10.1021/acs.inorgchem.2c02784