Solid-State 13C NMR and DFT Quantum-Chemical Study of Polymer Electrolyte Poly(2-ethyl-2-oxazoline)/AgCF3SO3

Abstract

Solid-state 13C NMR spectra and DFT calculations confirmed that dominant interaction in POZ/AgCF3SO3 polymer electrolyte is coordination between carbonyl groups and silver cation. Lower shielding of POZ carbonyl carbons and to a smaller extent also adjacent methylene carbons was found for the POZ/AgCF3SO3 complex in comparison with neat POZ, both in 13C NMR spectra and by DFT calculations on model systems. The POZ/AgCF3SO3 complex has a defined stoichiometry: two POZ monomeric units per one AgCF3SO3. A close contact between both components was determined from the Lee−Goldburg cross-polarization 1H → 13C dynamics. The shorter 13C spin−lattice relaxation times in the stoichiometric POZ/AgCF3SO3 sample in comparison with neat POZ indicate a formation of small amount (∼0.1%) of paramagnetic neutral silver.