title: A water-soluble pH-triggered molecular switch.
abstract: 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 (1)H 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.
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors.forename: Sergio
authors.initials: S
authors.lastname: Grunder
authors.forename: Psaras L
authors.initials: PL
authors.lastname: McGrier
authors.forename: Adam C
authors.initials: AC
authors.lastname: Whalley
authors.forename: Megan M
authors.initials: MM
authors.lastname: Boyle
authors.forename: Charlotte
authors.initials: C
authors.lastname: Stern
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart