The crown ether is a bulky molecule which effectively fills one side of the t-wof cage, with the sodium ion and its coordinating ether O atoms lying in the mid-plane of the cage.
Therefore, an acceleration of the non-catalyzed reaction by higher coordinating ethers can be deduced, explaining the reduced ee value in presence of these solvents.
The results of FTIR and 7Li MAS solid-state NMR indicate the Li+ ions are preferentially coordinated to the ether oxygen of PEG.
The results of DSC and the 7Li MAS solid-state NMR show that Li+ ions are preferentially coordinated to the ether oxygen of the PEG soft-segment when the salt concentration is below 0.1 mmol LiClO4 gPUU −1.
A coordination of nine to ten ether oxygens to the lanthanum ions has been found for the PEGM system by increasing the concentration of lanthanum triflate in the polymers and following the disappearance of the COC stretching vibration of non-coordinated ether oxygens.
In the LiCF3SO3PPG 3000) system, the Li+ ions preferred to coordinate to OH groups rather than to ether oxygens; at the composition LiCF3SO3PPG10, all OH groups were coordinated by both lithium and triflate ions, suggesting that the properties of these electrolytes depend to a large extent on metal ion to OH end-group interactions.
The 17O NMR data exhibit decreasing chemical shift changes with increasing chain length of glymes due to the increased number of ether oxygens coordinating each Li+ in the electrolytes.
Molecules in the assemblies are coordinated by means of the hydrogen bond between the oxygen atoms of the crown ether and the hydrogen atoms of the polyfluoroarene amino groups.
The Nd3+ ion environment varies greatly with its distance from the polymer surface: Nd3+ ions in the region near the surface coordinate one Cl− ion and eight ether oxygens belonging to upto 3 different polymer chains, while Nd3+ ions located deeper in the polymer coordinate two Cl− ions and five ether oxygens belonging to 2 different polymer chains.
Like Nafion-[H], SPEEK-[H] C3V and C1 environments afford IR group modes (C3V,HF (1087 cm−1); C3V,LF (1026 cm−1) and C1,HF (1362 cm−1); C1,LF (904 cm−1)) due to the mechanical coupling of vibrational internal coordinates of an ether link with those of the sulfonate or sulfonic acid exchange site.
He coordinates the European project ETHERPATHS [ 58], which aims to understand how diet modulates lipid homeostasis, specifically ether lipid metabolism.
