Ionic-liquid-like local structure in $LiNO_3-Ca(NO_3)_2-H_2O$ as studied by ion and solvent nuclei NMR relaxation

TL;DR

This study uses NMR relaxation measurements to reveal that a LiNO3-Ca(NO3)2-H2O system has an ionic liquid-like structure composed of specific charged units, providing insights into its local molecular organization.

Contribution

It demonstrates the ionic liquid-like local structure in a ternary aqueous nitrate system through NMR relaxation analysis, highlighting specific charged units.

Findings

System contains [Li(H2O)4]+ and [Ca(NO3)4]2- units

System exhibits ionic liquid-like local structure

NMR relaxation rates reveal molecular organization

Abstract

Relaxation rates in the $13mLiNO_3-6,5mCa(NO_3)_2-H_2O$ ternary system have been measured for nuclei of water ($^1H$ and $^{17}O$), anion ($^{14}N$), and both cations ($^7Li$, $^{43}Ca$). The data analysis reveals the system structure as consisting of two main charged units: [Li(H$_2$O)$_4$]$^+$ and [Ca(NO$_3$)$_4$]$^{2-}$. Thus the system presents inorganic ionic liquid like structure.