Vibrational spectra and phase transitions in Ni(CH 3COO) 24X 2O (X = H, D)

Abstract

The temperature dependence of the IR (4000—200 cm −1, between 300 and 90 K) and Raman (4000—40 cm −, between 300 and 130 K) spectra of the title compounds are reported. The bands observed at 90 or 130 K have been correlated with those at 300 K. Analysis of the vibrational spectra indicates one type of acetate and two types of water in the unit cell, a result which is consistent with the room temperature crystallographic data. The temperature evolution of the thermosensitive CH 3 modes in the Raman and IR spectra suggests two reorientational phase transitions at 264 ± 3 and 178 ± 3 K.