1H NMR spectra of triethylamine binary aqueous solutions as functions of concentration and temperature. The triethylamine rich phase

Triethylamine (Et3N) aqueous solutions with different weight contents of dissolved molecules (9, 18, 25, 30, and 42 wt% of Et3N) were studied for the first time by the H-1 NMR method in the region of the liquidliquid phase transition. After an interface between two phases was formed, anomalous inhomogeneous broadening of H-1 NMR lines of Et3N molecules was discovered in the Et3N rich phase. The inhomogeneous character of broadening depends on the weight content of dissolved molecules and is observed up to 313 K. It is concluded that the studied systems exist in the transition region between critical and classical states. (C) 2021 Elsevier B.V. All rights reserved.