School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
Dalton Trans. 2018 Dec 18;48(1):58-64. doi: 10.1039/c8dt04096f.
Metal coordination to a series of bis (imidazolium)…pillar[5]arene [2]rotaxanes through the formation of metal-carbene bonds facilitates a new strategy to restrict the shuttling motion in [2]rotaxanes. Whereas the pillar[5]arene macrocycle rapidly shuttles along the full length of the bis (imidazolium) rod for the parent [2]rotaxane, Ag(i) coordination to the imidazolium groups through the formation of N-heterocyclic carbenes leads to restricted motion, effectively confining the shuttling motion of the [2]rotaxane. The Ag(i) coordinated [2]rotaxanes can be reacted further, either removing the Ag-carbene species to recreate the parent [2]rotaxane, or reaction with more bulky Pd(ii) species to further restrict the shuttling motion through steric inhibition.
通过形成金属-卡宾键，将一系列双（咪唑基）…柱[5]芳烃[2]轮烷与金属配位，为限制[2]轮烷中的穿梭运动提供了一种新策略。对于母体[2]轮烷，柱[5]芳烃大环沿双（咪唑基）棒快速穿梭，而 Ag(i)通过形成 N-杂环卡宾与咪唑基配位，导致运动受限，有效地限制了[2]轮烷的穿梭运动。Ag(i)配位的[2]轮烷可以进一步反应，要么去除 Ag-卡宾物种以重新生成母体[2]轮烷，要么与更大体积的 Pd(ii)物种反应，通过空间位阻抑制进一步限制穿梭运动。
