| Autor: |
Munasinghe, Vihanga K., Hui Min Tay, Manawadu, Dilhan, Pancholi, Jessica, Zongyao Zhang, Beer, Paul D. |
| Předmět: |
|
| Zdroj: |
Dalton Transactions: An International Journal of Inorganic Chemistry; 9/14/2024, Vol. 53 Issue 34, p14220-14225, 7p |
| Abstrakt: |
The first heteroditopic [2]rotaxane host systems capable of strong and selective binding of lithium chloride ion-pair species are described. Importantly, a cooperative 'switch on' mechanism was found to operate, in which complexation of a lithium metal cation enhances the halide anion affinity of the rotaxanes via a combination of favourable proximal electrostatic and preorganised allosteric effects. The mechanically bonded rotaxane host design features a macrocycle component possessing a 2,6-dialkoxy pyridyl cation binding motif and an isophthalamide anion binding group, as well as an axle component functionalised with either a halogen bonding (XB) iodotriazole or hydrogen bonding (HB) prototriazole moiety. Extensive quantitative 1H NMR titration studies in CD3CN/CDCl3 solvent mixtures determined enhanced ion-pair binding affinities for lithium halides over the corresponding sodium or potassium halide salts, with the axle prototriazole-containing HB rotaxane in particular demonstrating a marked selectivity for lithium chloride. Solid-state X-ray crystallographic studies and computational DFT investigations provide evidence for a [2]rotaxane host axle-separated ion-pair binding mode, in which complementary cation and anion binding motifs from both the macrocycle and axle components act convergently to recognise each of the charged guest species. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
