The nuclear Overhauser enhancement (NOE) is a powerful tool of NMR spectroscopy extensively used to gain structural information in ionic liquids (ILs). A general model for the distance dependence of intermolecular NOE in ILs was recently proposed showing that NOE spots beyond the first solvation shell and accounts for long-range effects. This conclusion prompted for a deep rethinking of the NOE data interpretation in ILs. In this paper we present an extensive and quantitative study of N-propyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR<inf>13</inf>TFSI), the homologue with bis(fluorosulfonyl)imide (PYR<inf>13</inf>FSI), and their mixtures with LiTFSI based on <sup>1</sup>H-<sup>19</sup>F and <sup>1</sup>H-<sup>7</sup>LiNOE correlation experiments (HOESY). The former is mainly tuned on long-range interactions, the latter on short-range ones, due to the small and large Larmor frequency differences of the involved nuclei. The collected data are discussed in two different way: long-range <sup>1</sup>H-<sup>19</sup>FNOEs spot on the polar/apolar domains within the ILs, whereas short-range (e.g. regarding the first coordination shell) <sup>1</sup>H-<sup>7</sup>LiNOEs describe the contacts between first neighbors, with interesting correlation with the distances' statistics derived by crystallographic data of related systems.
|Numero di pagine||8|
|Rivista||Journal of Molecular Liquids|
|Stato di pubblicazione||Published - 2015|
All Science Journal Classification (ASJC) codes