A Water-Soluble pH-Triggered Molecular Switch

作者:Grunder Sergio; McGrier Psaras L; Whalley Adam C; Boyle Megan M; Stern Charlotte; Stoddart J Fraser*
来源:Journal of the American Chemical Society, 2013, 135(47): 17691-17694.
DOI:10.1021/ja409006y

摘要

A bistable donor-acceptor [2]catenane, which is composed of a crown ether containing a hydroquinone unit and a 1,5-diaminonaphthalene unit, interlocked mechanically by cyclobis(paraquat-p-phenylene) as its tetrachloride, exists as a mixture of translational isomers, both in the solid state and in aqueous solution. UV/vis and H-1 NMR spectroscopies demonstrate that this isomeric mixture can be switched in water in the presence of hydrochloric acid to afford a single diprotonated derivative in which only the hydroquinone unit resides inside the cavity of the tetracationic cyclophane. Treatment with 1,4-diazabicyclo[2.2.2]octane resets the molecular switch.