INFRARED SPECTRUM OF SOLID AND MATRIX ISOLATED $H_{2}O_{2}$ AND $D_{2}O_{2}$

Author Institution: Pitman-Dunn Research Laboratories, Frankford ArsenalThe 200 to $4000 cm^{-1}$ spectra of thin films of pure solid $H_{2}O_{2}$ or $D_{2}O_{2}$ vary according to the temperature of deposition. Amorphous films deposited at $-190^{\circ}C$ transform after a few minutes heat treatment to yield spectra attributed to the $D^{4}_{4}$ crystalline form$^{1, 2}$. However, if the deposition is carried out at $-78^{\circ}$, the spectra are markedly different from any previously reported. Moreover, the spectra of heat treated films change with time to become nearly identical with those deposited at $-78^{\circ}$. These observations suggest the existence of a second, more stable crystalline form. In nitrogen and argon matrices reproducible multiplets were observed in the $\nu_{1}, \nu_{5}$ region and in the $\nu_{2}, \nu_{6}$ region. Interpretation and assignment of these multiplets are based upon intra-molecular rotation and coupling of internal modes. The broad band observed near $380 cm^{-1}$ has been attributed to the torsional mode, $\nu_{4}$. We have explored the possibility that the unusual breadth of this band may be due to the contribution of several dihedral conformations or to different matrix sites. Normal coordinate analysis for a number of different conformations have been completed. $^{1}$ R.L. Miller and D.F. Hornig, J. Chem. Phys., 34, 265 (1961). $^{2}$ P.A. Giguere and K.B. Harvey, J. Mol. Spec., 3, 36 (1959)