abstract
We present herein the development of a new polycationic cyclophane: the red box, second in a series of hydrazone-based analogues of the well-known organic receptor cyclobis(paraquat-p-phenylene) cyclophane (blue box). The macrocycle has been prepared in an excellent yield in aqueous media, and shows both a remarkable pH-responsiveness and unusual hydrolytic stability of the two hydrazone C=N bonds, associated with charge delocalization of the amine lone pair. Whilst in aqueous media the red box is able to complex a variety of aromatic substrates, both in its acidic and basic form, in organic media the cyclophane is only able to capture those in the acidic form, resulting in supramolecular pHresponsiveness.
keywords
ASSEMBLED PD-II; SWITCHES; COMPLEXATION; ROTAXANES; CATENANE; DRIVEN
subject category
Chemistry
authors
Blanco-Gomez, A; Neira, I; Barriada, JL; Melle-Franco, M; Peinador, C; Garcia, MD
our authors
Manuel Melle-Franco
Principal Researcheracknowledgements
This research was supported by the Ministerio de Economia y Competitividad (MINECO FEDER, Grant CTQ2016-75629-P) and Xunta de Galicia (ED431C 2018/39). MMF acknowledges support from the Portuguese Foundation for Science and Technology (FCT), under the projects PTDC/FIS-NAN/4662/2014, IF/00894/2015, and FCT Ref. UID/CTM/50011/2019 for CICECO-Aveiro Institute of Materials. I. N. thanks the MECD (FPU program) for financial support. Dedicated to Professor Jose Maria Quintela on the occasion of his retirement.