Fast redox-triggered shuttling motions in a copper rotaxane based on a phenanthroline-terpyridine conjugate
Coronado, E.; Gaviña, P.; Ponce, J.; Tatay, S.
Organic and Biomolecular Chemistry 12(38): 7572-7580
2014
ISSN/ISBN: 0969-0700 PMID: 25139602 Document Number: 672638
Fast shuttling motions in solution have been observed by cyclic voltammetry in a Cu(I/II)-based [2] rotaxane. In the reported system, the different coordination preferences of both copper oxidation states are exploited to promote the electrochemically-triggered gliding of the ring from a tetra to a pentacoordinated site and vice versa. The thread of this rotaxane consists of a tridentate 2,2':6',2''-terpyridine chelating unit directly bonded through its 5-position to the 3-position of the bidentate 1,10-phenanthroline unit. This distribution reduces to a minimum the distance between the two coordination sites and lessens the congestion around the tetrahedral environment. These two factors have been demonstrated to highly increase the kinetics of the switching process. In addition, the electrochemical experiments carried out in different solvent mixtures evidenced the influence of the solvent on the shuttling mechanism.