1. para–Phenylenediamine Dimer as a Redox–Active Guest for Supramolecular Systems.
- Author
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Janovský, Petr, Springer, Andreas, Filip, Jaroslav, Prucková, Zdeňka, Nečas, Marek, Rouchal, Michal, Schalley, Christoph A., and Vícha, Robert
- Subjects
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CUCURBITURIL , *CYCLODEXTRINS , *ISOTHERMAL titration calorimetry , *REDUCING agents , *CYCLIC voltammetry , *BINDING sites , *MASS spectrometry - Abstract
Redox–active components are highly valuable in the construction of molecular devices. We combined two p‐phenylenediamines (p‐PDA) with a biphenyl (BiPhe) unit to prepare a supramolecular guest 4 consisting of three binding sites for cucurbit[7/8]uril (CBn) and/or cyclodextrins (CD). Supramolecular properties of 4 were investigated using NMR, UV‐vis, mass spectrometry and isothermal titration calorimetry. Our analysis revealed that 4 forms higher–order host–guest complexes, wherein a CD unit occupies the central BiPhe site, secured by two CBn units at the terminal p‐PDA sites. Additionally, 1 : 1 complexes with α‐CD and β‐CD, a 1 : 2 complex with γ‐CD and 2 : 1 complexes with CB7 and CB8 were identified. Through UV‐vis and cyclic voltammetry, redox processes leading to the formation of a stable, deep blue dication diradical of 4 are elucidated. Furthermore, it is demonstrated that CB7 selectively protects oxidised 4 from reduction in the presence of a reducing agent. The supramolecular and redox properties of the structural motif represented by 4 render it an interesting candidate for the construction of supramolecular devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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