A spectroscopic and thermodynamic investigation of some iodine oxygen fluorine compounds

Abstract

The solid-state infrared and Raman spectra of the dioxodifluoroiodate salts, MIO2F2 (M=Na, K, Rb and NH4), iodyl fluoride, IO2F, and the Raman spectrum of iodine oxide trifluoride, IOF3 are reported. Assignment - of the vibrational frequencies of the have been made and approximate stretching force constants calculated. Shifts in the positions of the stretching modes of with changing cation are discussed. The vibrational spectrum of iodyl fluoride indicates the presence of a polymeric structure and various possible arrangements are suggested. The synthesis of complexes involving the iodyl ion, have been attempted. Colorimetric measurements, in the isoperibol mode, of the enthalpies of hydrolysis of the dioxodifluoroiodate salts, iodine oxide trifluoride, iodyl fluoride, iodine pentafluoride and 'hexafluoroiodate compounds, are reported. Using these and ancillary data the enthalpies of formation of the compounds have been calculated. Enthalpies of Solution of iodic acid at varying dilutions have been measured in order to supplement the data needed in the determination of the enthalpy of formation of iodine pentafluoride. The value thus derived is in good agreementwith those found from/methods. 'Thermochemical' radii of the ionsand IF- have been calculated from accepted procedures inorder to determine the lattice energies of the salts. Additional lattice energies and enthalpies of formation of other salts containing these anions are thus reported.