Temperature-Induced Change of Water Structure in Aqueous Solutions of Some Kosmotropic and Chaotropic Salts.

Ferenc Kovács,Sándor Kunsági-Máté,Heng Li,Hui Yan

doi:10.3390/ijms222312896

Abstract

The hydrogen bond structure of water was examined by comparing the temperature dependent OH-stretching bands of water and aqueous NaClO4, KClO4, Na2SO4, and K2SO4 solutions. Results called attention to the role of cations on top of the importance of anions determining the emerging structure of a multi-layered system consisting single water rings or multi-ring water-clusters.

Highlights

The main medium along the metabolic pathways, pharmaceutical and biological processes is water
This study focuses on the change of water structure in lieu of the ionic solutes of chaotropic sodium and potassium perchlorate and the kosmotropic sodium and potassium sulphate
The water cluster structures were optimized using the B3LYP density functional [32,33] augmented with the D3 dispersion correction [34] of Grimme et al The geometry optimizations and the vibrational analysis were performed using the TZVP basis set [35]

Summary

Introduction

The main medium along the metabolic pathways, pharmaceutical and biological processes is water. Besides the structure of pure water, the weak interactions of water and bioactive molecules attract distinct attention in the fields of pharmacy, life, and medical sciences through quantum chemical topology [7,8] because the equilibrium of complex formation is fundamentally dependent on the variation of entropy. It is well-known, that the wide band around 3200 cm−1 and 3400 cm−1 in the Raman spectra of water is associated with molecular vibrations coming from the stretching of O-H···O bonds and a Raman spectroscopy commonly used to investigate water structure. The samples were excited by non-coherent radiation of Xe-lamp and the temperature-dependent Raman spectra were recorded

Results

Theoretical Calculations

Data Processing

Conclusions