Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968, USA.
J Am Chem Soc. 2011 Mar 2;133(8):2760-5. doi: 10.1021/ja110160j. Epub 2011 Feb 3.
Electrochemically generated Lu(3)N@I(h)-C(80) dianions react with the electrophile, PhCHBr(2), to produce a methano derivative of Lu(3)N@I(h)-C(80)(CHC(6)H(5)) (1) with high regioselectivity. The compound was characterized by MALDI-TOF, NMR, and UV-vis-NIR absorption spectroscopy. Electrochemical characterization of this Lu(3)N@I(h)-C(80)(CHC(6)H(5)) derivative showed the typical irreversible reductive behavior of the pristine Lu(3)N@I(h)-C(80), similar to those observed for Bingel adducts of Lu(3)N@I(h)-C(80). Using the same conditions, the reaction between Sc(3)N@I(h)-C(80) dianions and PhCHBr(2) was conducted for comparison. Unexpectedly, no nucleophilic reaction was observed, indicating that Sc(3)N@I(h)-C(80) dianions are not reactive toward the electrophile. Theoretical studies for both dianionic Lu(3)N@I(h)-C(80) and Sc(3)N@I(h)-C(80) showed that the HOMO is more highly localized on the fullerene cage for Lu(3)N@I(h)-C(80) and more localized on the inside cluster for Sc(3)N@I(h)-C(80), providing an explanation for the drastically different reactivities observed.
电化学生成的 Lu(3)N@I(h)-C(80) 二负离子与亲电试剂 PhCHBr(2) 反应，生成 Lu(3)N@I(h)-C(80)(CHC(6)H(5))(1) 的甲氧基衍生物，具有高区域选择性。该化合物通过 MALDI-TOF、NMR 和 UV-vis-NIR 吸收光谱进行了表征。对该 Lu(3)N@I(h)-C(80)(CHC(6)H(5)) 衍生物的电化学特性进行了表征，结果表明其具有原始 Lu(3)N@I(h)-C(80) 的典型不可逆还原行为，类似于 Lu(3)N@I(h)-C(80) 的 Bingel 加合物所观察到的行为。在相同条件下，进行了 Sc(3)N@I(h)-C(80) 二负离子与 PhCHBr(2) 的反应进行比较。出乎意料的是，没有观察到亲核反应，表明 Sc(3)N@I(h)-C(80) 二负离子对亲电试剂没有反应性。对阴离子 Lu(3)N@I(h)-C(80) 和 Sc(3)N@I(h)-C(80) 的理论研究表明，HOMO 对于 Lu(3)N@I(h)-C(80) 在富勒烯笼上的局域化程度更高，而对于 Sc(3)N@I(h)-C(80) 在内部簇上的局域化程度更高，这为观察到的截然不同的反应活性提供了解释。
