Dynamics of binary mixtures of an ionic liquid and ethanol by NMR

MARTINS, JOÃO PEDRO DE ALMEIDA; STAPF, SIEGFRIED; SEBASTIÃO, PEDRO J.; VACA CHÁVEZ, FABIÁN; ORDIKHANI SEYEDLAR, AMIN; JARDIM BEIRA, MARIA JOSÉ; MATTEA, CARLOS

MAGNETIC RESONANCE IN CHEMISTRY

JOHN WILEY & SONS LTD

Año: 2017

0749-1581

A study of molecular dynamics of the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoro-methylsulphonyl)imide([Emim][Tf2N]) in solution with deuterated ethanol at different molar concentration and temperatures is presented. The studywas performed using 1H and 2H nuclear magnetic relaxation and 2H 1D spectroscopy.The temperature dependence of thespin?lattice relaxation time T1 of the cations allows the evaluation of the activation energies of the rotational degree of freedomof these molecules. The viscosity in the binary system increases with the concentration of ionic liquid. However, theactivation energy in the cation molecules decreases when the concentration of the ionic liquid increases, indicating that therotational dynamics is facilitated. This behavior is explained from the fact that the presence of the ionic liquid in the systemdisrupts the degree of intermediate range order expected in the alcohol system.