VIBRATIONAL SPECTROSCOPY OF SILVER PERCHLORATE AND SILVER TRIFLUOROMETHANESULFONATE SOLUTIONS IN ACRYLONITRILE

摘要

Solutions of silver trifluoromethanesulfonate (''triflate'') and silver perchlorate in acrylonitrile, over a range of concentrations between 0.5 and 4 mol-kg(-1) have been analyzed by dispersive infrared and Fourier-transform Raman spectroscopy. The spectral regions studied include the solvent v(C drop N) fundamental and several anion internal modes. The silver ion solvation number in the infinite dilution limit is 3 in both systems. This number falls when the salt concentration is increased because of the ionic pairing, which is slightly more intense for silver perchlorate solutions, with a calculated spectroscopic association constant 0.23+/-0.08 kg-mol(-1). For silver triflate solutions, the spectroscopic association constant is 0.17+/-0.05 kg-mol(-1). In both cases, the ionic pair structure is bidentate and silver ion preserves two molecules of acrylonitrile in its first solvation shell. [References: 57]