Molecular mobility of counterion functional groups in ionic liquid 1-ethyl-3-methylimidazolium acetate according to 1H and 13C NMR relaxation data

: V V Matveev, D A Markelov, V I Chizhik, P Ingman, E Lähderanta

Publisher: Internal Edition, Springer

: NEW YORK; 233 SPRING ST, NEW YORK, NY 10013 USA

: 2013

: Russian Chemical Bulletin

: Russ.Chem.Bull.

: 9

: 62

: 9

: 1985

: 1990

: 6

: 1066-5285

DOI: https://doi.org/10.1007/s11172-013-0288-6

1-Ethyl-3-methylimidazolium acetate was studied by NMR relaxation. The temperature dependences of the spin-lattice relaxation rates (1/T (1)) for H-1 and C-13 were obtained. The curves with maxima were observed for the majority of the temperature dependences 1/T (1), which provided a reliable temperature dependence of the correlation times (tau(c)). In the low-temperature range, the proton relaxation rates tend to an asymptotic value, which is related, most likely, to spin diffusion manifested in the studied samples. The values of correlation times tau(c) calculated for H-1 and C-13 of the same functional group almost coincide at high temperatures, which confirms that the used approach is adequate for the determination of characteristic times of rotational reorientation of counterions in the studied ionic liquid.