Vibrational Spectrum and Force Field of Xenon Tetroxide

摘要

Infrared and Raman spectra are reported for Xe16O4and Xe18O4vapor. The infrared band contours are analyzed to give values for the Coriolis constants and the xenon isotopic frequency shift, and anharmonicity corrections are estimated for the fundamental frequencies. General quadratic force constants are calculated, using as constraints the16Osngbnd;18Oand129Xesngbnd;132Xefrequency shifts and the Coriolis constants. The force field is significantly different from those of RuO4and OsO4. Valence stretching force constants arefrequals;6.40 plusmn; 0.10thinsp;mdynsol;Aring;andfrrequals;minus;0.08 plusmn; 0.04thinsp;mdynsol;Aring;;the negative value of the interaction constantfrrindicates that the bonding differs appreciably from that in the transition metal tetroxides. Standardhyphen;state thermodynamic functions for XeO4vapor are calculated for the temperature range 250ndash;400deg;K.