Study of Ion Pairing in Acetonitrile Solutions Containing Magnesium PerchlorateUsing ATR-FTIR Spectroscopy

摘要

A study of ion pairing for Mg(C104)2 dissolved in acetonitrile has been carriedout using attenuated total reflection FTIR spectroscopy. The present results indicate that the coordination number for ligands around the Mg2+ ion is approximately four, and not six as previously reported Ion pairing is relatively strong with 70 percent of the Mg2+ ions forming contact ion pairs with on perchlorate ion. The spectral characteristics of acetonitrile associated with Mg2+ have been clearly distinguished from those of the free molecule. By comparing spectra in deuterated and protonated solvents, it has been shown for the first time in solution, that the ion paired perchlorate ion has an absorption band at 933 cm-1. The effect of Fermi interaction on the position of the blue shifted C = N band for coordinated acetonitrile is examined and discussed with respect to determination of the effect of the cation charge/radius ratio on the shifted band. ion pairing, ATR spectra Of Mg(ClO4)2 solutions, coordination of Mg2+ in acetonitrile.