Barravecchia Prado, Liliana InésBlanco-Gómez, ArturoNeira, IagoSkackauskaite, RamintaVila García, AlejandroRey-Rico, AnaPeinador, CarlosGarcía, Marcos D.2023-01-102023-01-102022-10-07Liliana Barravecchia, Arturo Blanco-Gómez, Iago Neira, Raminta Skackauskaite, Alejandro Vila, Ana Rey-Rico, Carlos Peinador, and Marcos D. García. 2022. “Vermellogens” and the Development of CB[8]-Based Supramolecular Switches Using pH-Responsive and Non-Toxic Viologen Analogues. Journal of the American Chemical Society 144 (41), 19127-19136. DOI: 10.1021/jacs.2c085751520-5126http://hdl.handle.net/2183/32326[Abstract] We present herein the “vermellogens”, a new class of pH-responsive viologen analogues, which replace the direct linking between para-substituted pyridinium moieties within those by a hydrazone functional group. A series of such compounds have been efficiently synthesized in aqueous media by hydrazone exchange reactions, displaying a marked pH-responsivity. Furthermore, the parent N,N′-dimethylated “vermellogen”: the “red thread”, an analogue of the herbicide paraquat and used herein as a representative model of the series, showed anion-recognition abilities, non-reversible electrochemical behavior, and non-toxicity of the modified bis-pyridinium core. The host–guest chemistry for the “red thread” with the CB[7,8] macrocyclic receptors has been extensively studied experimentally and by dispersion corrected density functional theory methods, showing a parallel behavior to that previously described for the herbicide but, crucially, swapping the well-known redox reactive capabilities of the viologen-based inclusion complexes by acid–base supramolecular responsiveness.engAtribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/CationsComplexationPotential energyPyridinesTitrationjournal articleopen access10.1021/jacs.2c08575