Structure of the Alkali Hydroxides. V. The Infrared Spectra of Matrixhyphen;Isolated RbOH, RbOD, NaOH, and NaOD

摘要

The infrared spectra of matrixhyphen;isolated RbOH, RbOD, NaOH, and NaOD have been observed. Both the alkalihyphen;metalndash;oxygen stretchngr;1and the bending modengr;2have been assigned for each species. The metalndash;oxygen stretching mode is found at 354.4, 345, 431, and 422 cmminus;1for RbOH, RbOD, NaOH, and NaOD, respectively; the bending modengr;2is observed at 309.0, 229, 337, and 250 cmminus;1, respectively. Combination of the results of this study with the microwave measurements for RbOH and RbOD indicates an essentially linear structure for these species. The isotope shift forngr;2observed in NaOH coupled with reasonable bond lengths indicates an equilibrium configuration of NaOH which probably does not deviate significantly from linearity. The assumption of a linear model with a harmonic bending potential yields force constants of 0.046thinsp;times;thinsp;10minus;18and 0.053thinsp;times;thinsp;10minus;18Nm (0.046 and 0.053 mdynmiddot;Aring;) for RbOH and NaOH, respectively. These results are consistent with our previously reported results for CsOH.