Effect of tetraphenylphosphonium and tetraphenylborate ions on the water structure in aqueous solutions; FTIR studies of HDO spectra
Abstract
FTIR spectroscopy has been used to study interactions of Ph4B- and Ph4P+ ions with water in aqueous solutions. The effect of Ph4BNa and Ph4PCl on the HDO vibration band in the fundamental region has been investigated. A new modification of the difference spectra method has been applied for the analysis of the spectral data. The results have revealed distinct differences in hydration of Ph4B- and Ph4P+ ions: Ph4B- ion strongly decreases the hydrogen-bond energy of surrounding water molecules, while Ph4P+ ion changes it slightly. The effect of Ph4B- is determined by anion–water interactions, while the effect of Ph4P+ is determined by water–water interactions around the cation. The changes in the energy of water hydrogen bonds upon the ions have been evaluated.