Correlation of Dielectric Properties with Structure and H-Bonding for Liquids

Abstract

A study focused on the correlation among dielectric properties, molecular structure, and H-bonding is presented using liquid formamides with increasing carbon chain lengths as a model series. 1H NMR is used to determine the extent of H-bonding via Abraham solute hydrogen bond acidity parameter, A. The results show a clear quantitative correlation, with higher A linked with increased relaxation times (τ) and a drop in the static dielectric constants (ϵs), with differences between the 1 and 2° amides observed. Overall, the findings advance our understanding of the intricate relationship between dielectric properties and H-bonding, with potential applications toward the design of materials exhibiting tailored dielectric properties and the study of amide-containing molecules (such as DNA, peptides, proteins, and nylon polymers) and other liquids which may associate via H-bonding.