Zhou Zheng, Wei Zheng, Ikemoto Koki, Sato Sota, Isobe Hiroyuki, Petrukhina Marina A
Department of Chemistry, University at Albany, State University of New York, 1400 Washington Ave, Albany, NY, 12222, USA.
Department of Chemistry, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.
Angew Chem Int Ed Engl. 2021 May 10;60(20):11201-11205. doi: 10.1002/anie.202100942. Epub 2021 Apr 8.
Chemical reduction of a naphthylene macrocycle, [6]cyclo-2,7-naphthylene ([6]CNAP, 1), with alkali metals, Li and K, revealed the accessibility of the doubly-reduced state of 1. The macrocyclic 1 anion was isolated in different coordination environments and crystallographically characterized. The single-crystal X-ray diffraction confirmed the formation of contact-ion complexes with one Li and two K ions in THF, and a "naked" dianion in the solvent-separated ion product with K ions in the presence of 18-crown-6 ether. The detailed structural analysis of 1 showed that the π-conjugation over the biaryl linkages between naphthylene panels were enhanced upon two-fold reduction, which was rationally explained by theoretical calculations.
用碱金属锂和钾对萘大环化合物[6]环-2,7-萘撑（[6]CNAP，1）进行化学还原，揭示了1的双还原态的可及性。大环1阴离子在不同的配位环境中被分离出来，并通过晶体学进行了表征。单晶X射线衍射证实，在四氢呋喃中与一个锂离子和两个钾离子形成了接触离子络合物，在18-冠-6醚存在下与钾离子形成了溶剂分隔离子产物中的“裸”二价阴离子。对1的详细结构分析表明，萘撑面板之间的联芳基键上的π共轭在两次还原后增强，这通过理论计算得到了合理的解释。
