Vacuum UV spectrum of C3 trapped in argon at 8 K

Abstract

The vacuum ultraviolet absorption spectrum to 1200 Å has been obtained for the products from the evaporation of graphite at 2700 °C, trapped in argon at 8 K. Based on correlations with the 1Πu–X1Σ+g transition of C3 in the near ultraviolet, the results of 13C substitution, and other observational evidence, it is proposed that a band system originating at 1890 Å be assigned to the 1Σ+u–X1Σ+g transition of C3. Vibrational analysis yields ν1′≂1080, ν2′≂300, and ν3′≂780 cm−1 for the 1Σ+u state.