Resonance Raman and far infrared spectroscopic studies of triiodide complexes formed in the reaction of iodine with some polycyclic amines

Abstract

The solid charge transfer complexes formed in the reaction of iodine with the polycyclic amines 1,4,8,12-tetraazacyclopentadecane (TACPD) and meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (HMTACTD) have been investigated by resonance Raman and far i.r. spectroscopy. The spectra can be explained entirely by the presence of the I−3 ion in these complexes, whose composition agreed fairly well with the formulas (TACPD) I+·I−3 and (HMTACTD) I+·I−3. The three vibrations of the I−3 ion, νs(I—I), νas(I—I) and δ(I−3), are assigned at 109, 130 and 60 cm−1 for (TACPD)I+·I−3. and at 110, 145 and 61 cm−1 for (HMTACTD) I+·I−3. The structure and geometry of the I−3 ion is discussed in view of the Raman and i.r. band activities.