THE INTRARED SPECTRA OF THICK FILMS OF $CO_{2}$ AND $CO_{2}+H_{2}O$ AT LOW TEMPERATURES

Abstract

High resolution infrared absorption studies on thick films of $CO_{2}$ and of dilute solid solutions of $H_{2}O$ in $CO_{2}$ have been made at $50^\circ K$ and at $4^\circ K$ . The isolation of $H_{2}O$ in the $CO_{2}$ matrix at $50^\circ K$ is moderately good; monomer and dimer absorptions have been assigned in the $1600-1650 cm^{-1}$ region. A spectroscopically observable complex between $CO_{2}$ and $H_{2}O$ is not formed. Similar systems of lattice vibrations have been observed in combination with both $\nu_{2}$ and $\nu_{3}$. In very thick films of pure $CO_{2}, \nu_{1}$ appears, weakly, at $50^\circ K$ . In samples deposited at $4^\circ K$ the $\nu_{1}$ absorption is intensified, and $2\nu_{2}$ is also observed.