On–off-switched crown ether–metal ion complexation by photoinduced intramolecular ammonium group ‘tail-biting’
Abstract
A new photoresponsive crown ether with an ammonium-group tail was synthesised in which the ion-binding ability changes in response to photoirradiation because of competitve intramolecular ‘tail-biting’ in the cis-form produced by photoisomerisation.