Spectrum of C3

The enthalpy of sublimation of C3 as determined by a second law method using both emission and absorption measurements agrees with total vapor pressure and mass spectrometer measurements. The enthalpy agreement and integrated absorption coefficient measurements demonstrate that the so-called continuum of C3 is a pseudocontinuum and involves the same bound states as the discrete Swings bands of C3(A1Πu↔X1Σg+). ΔH0°=188±5 kcal/mole for the sublimation of C3 yields an oscillator strength for the 4050 A bands of C3 of 0.13 within a factor of 2.