Benzo-21-crown-7-based [1]rotaxanes: syntheses, X-ray crystal structures, and dynamic characteristics.
Two B21C7-based [1]rotaxanes were synthesized in high yields by means of copper(II)-mediated Eglinton coupling and a subsequent Pd/C-catalyzed reduction under H2. X-ray single-crystal analysis shows that [1]rotaxane takes on a self-entangled conformation, wherein the macrocycle is threaded by its own tail. Moreover, it was found that [1]rotaxane with a flexible skeleton had more rotational motions than that of one with a rigid skeleton.
Department of Chemistry, Taizhou University , Taizhou, 318000, P. R. China , Department of Chemistry, Zhejiang University , Hangzhou 310027, P. R. China , and Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University , Shanghai 200062 P. R. China.
Qizhong
Q
Zhou
Peifa
P
Wei
Yanyan
Y
Zhang
Yihua
Y
Yu
Xuzhou
X
Yan