Na+ polarizability due to collective Na+ ion motion in disodium salts of 2,6-bis(diethylaminomethyl)phenolate di-N-oxides as a function of the electron density at the O atom of the phenolate group

Abstract

Six disodium aurates of 2,6-bis(diethylaminomethyl)-3,4-R-phenolate di-N-oxides (2,6-DNO) have been studied by FTIR spectroscopy as a function of the electron density of the O atom at the phenolate group. In the cases R = 4-C₆H₅ and R = 4-Cl, a continuum in the far-infrared region was observed indicating large Na⁺ polarizability due to collective Na⁺ ion motion within the two Na⁺ bonds. The Na⁺ polarizability is much smaller than the respective Li⁺ polarizability. This is due to the larger mass of the Na⁺ ions compared with that of the Li⁺ ions, since as a result of this, the amplitudes of the Na⁺ ion motion are much smaller than those of the Li⁺ ions.