Far-i.r. spectra of charge-transfer complexes between IX (X = Cl, Br) and some pyridine and quinoline bases

Abstract

Far-i.r. spectra of charge-transfer (CT) complexes of IX (X = Cl, Br) with pyridine, quinoline and their derivatives have been measured in solids. Assignments for the intermolecular NI stretching and the modified IX stretching vibrations are proposed. The force constants for these vibrations have been calculated assuming a linear triatomic model, putting a donor molecule as a point mass. The relationship between the relative decrease in the IX stretching force constants and the p K a values of donor molecules is discussed.