Infrared and Raman Spectra of Carbon Suboxide in Condensed Phases

Abstract

Infrared and Raman spectra of liquid, crystalline, and matrix‐isolated carbon suboxide have been obtained in the region 20–4000 cm⁻¹. A previously unreported solid—solid transition has been observed at 115°±5°K, and possible structures for both crystalline phases have been inferred from the spectroscopic results. The π_u central‐carbon bending mode ν₇ has been identified in the liquid phase at 72±2 cm⁻¹. The problem of ``disappearing'' sum bands is discussed, and a revised vibrational assignment and force‐constant analysis for carbon suboxide is presented.