RESUMO
A glycoluril-based molecular clip incorporating two tetrathiafulvalene (TTF) sidewalls has been synthesized using a straightforward Diels-Alder synthetic route and its ability to self-assemble with fullerene C60 in a 2 : 1 stoichiometry has been demonstrated in solution.
RESUMO
Glycoluril-based molecular clips incorporating tetrathiafulvalene (TTF) sidewalls have been synthesized through different strategies with the aim of investigating the effect of electrochemical and spatial properties for binding neutral accepting guests. We have in particular focused our study on the spacer extension in order to tune the intramolecular TTF···TTF distance within the clip and, consequently, the redox behavior of the receptor. Carried out at different concentrations in solution, electrochemical and spectroelectrochemical experiments provide evidence of mixed-valence and/or π-dimer intermolecular interactions between TTF units from two closed clips. The stepwise oxidation of each molecular clip involves an electrochemical mechanism with three one-electron processes and two charge-coupled chemical reactions, a scheme which is supported by electrochemical simulations. The fine-tunable π-donating ability of the TTF units and the cavity size allow to control binding interaction towards a strong electron acceptor such as tetrafluorotetracyanoquinodimethane (F4-TCNQ) or a weaker electron acceptor such as 1,3-dinitrobenzene (m-DNB).
RESUMO
An efficient synthesis of unprecedented fused extended-tetrathiafulvalene-dipyridoquinoxaline (exTTF-dpq) dyad is described through the Horner-Wardsworth-Emmons olefination methodology from the dipyrido[3,2-a:2',3'-c]-benzo[3,4]phenazine-11,16-quinone (NqPhen) ligand starting material. This exTTF-dpq dyad is demonstrated to act as a dual redox and colorimetric sensor for cations exploiting the proximity between the redox tetrathiafulvalene and the optical phenanthroline detecting sites. Its ability for sensing cations from the d-group metal transitions (Fe(2+), Ni(2+), and Zn(2+)) and also with varied cations such as Ca(2+) and Pb(2+) is presented.
Assuntos
Corantes Fluorescentes/química , Compostos Heterocíclicos/química , Fenantrolinas/química , Cátions/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura MolecularRESUMO
Intense current interest in supramolecular chemistry is devoted to the construction of molecular assemblies displaying controlled molecular motion associated to recognition. On this ground, molecular clips and tweezers have focused an increasing attention. This tutorial review points out the recent advances in the construction of always more sophisticated molecular clips and tweezers, illustrating their remarkably broad structural variety and focusing on their binding ability towards neutral guests. A particular attention is brought to recent findings in dynamic molecular tweezers whose recognition ability can be regulated by external stimuli. Porphyrin-based systems will not be covered here as this very active field has been recently reviewed.
Assuntos
Modelos Químicos , Acridinas/química , Alcinos/química , Antracenos/química , Benzofuranos/química , Fulerenos/química , Imidazóis/química , Conformação Molecular , Porfirinas/química , Rotaxanos/químicaRESUMO
An application of the Horner-Wadsworth-Emmons reaction carried out on a ruthenium compound as the electrophilic precursor is described for the synthesis of fused donor-acceptor system 1 based on an extended tetrathiafulvalene and a ruthenium complex of dipyridoquinoxaline units.