Using metal substrates to enhance the reactivity of graphene towards Diels–Alder reactions
Using metal substrates to enhance the reactivity of graphene towards Diels–Alder reactions
复制标题
使用金属基底增强石墨烯对狄尔斯-阿尔德反应的反应活性
DOI：
10.1039/d2cp01842j
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发表时间：
2022
影响因子：
3.3
通讯作者：
Yan, Mingdi
中科院分区：
文献类型：
--
作者：
Yang, Xiaojian;Chen, Feiran;Kim, Min A.;Liu, Haitao;Wolf, Lawrence M.;Yan, Mingdi
Diels-Alder（DA）反应是一种经典的环加成反应，涉及二烯和亲二烯体形成环己烯，是最通用的有机反应之一。理论预测，由于原始石墨烯的化学反应性低，在原始石墨烯上的DA反应在化学上是不利的。我们假设像Ni这样的金属可以通过电荷转移增强石墨烯对DA反应的反应性。结果确实表明，金属基底增强了石墨烯在与二烯2，3-二甲氧基丁二烯（DMBD）和亲二烯体马来酸酐（MAH）的DA反应中的反应性，活性增强的顺序为Ni > Cu，并且两者都比负载在硅晶片上的石墨烯更具反应性。速率常数估计是两倍高的石墨烯上支持镍比硅晶片。计算结果支持实验获得的Ni > Cu的速率趋势，两者预测都大于未支撑的石墨烯，这通过与强相互作用的Ni的电荷转移效应中反映的增强的石墨烯-基底相互作用来解释。这项研究为通过基底选择增强原始石墨烯的化学反应性开辟了一条新途径。
The Diels–Alder (DA) reaction, a classic cycloaddition reaction involving a diene and a dienophile to form a cyclohexene, is among the most versatile organic reactions. Theories have predicted thermodynamically unfavorable DA reactions on pristine graphene owing to its low chemical reactivity. We hypothesized that metals like Ni could enhance the reactivity of graphene towards DA reactions through charge transfer. The results indeed showed that metal substrates enhanced the reactivity of graphene in the DA reactions with a diene, 2,3-dimethoxy butadiene (DMBD), and a dienophile, maleic anhydride (MAH), with the activity enhancement in the order of Ni > Cu, and both are more reactive than graphene supported on silicon wafer. The rate constants were estimated to be two times higher for graphene supported on Ni than on silicon wafer. The computational results support the experimentally obtained rate trend of Ni > Cu, both predicted to be greater than unsupported graphene, which is explained by the enhanced graphene–substrate interaction reflected in charge transfer effects with the strongly interacting Ni. This study opens up a new avenue for enhancing the chemical reactivity of pristine graphene through substrate selection.