Vibrational relaxation dynamics of the X̃1∑g+ state of C3

The vibrational relaxation dynamics of the ground ¹∑_g⁺ electronic state of C₃ has been studied following IR multiple photon dissociation of allene. Wavelength and time resolved spectra, using dye laser-induced fluorescence are used to characterize the vibratioanl levels and their corresponding rise and decay rates. Vibrational relaxation rates are reported for C₃ (¹∑⁺_g, 100 or 110) in the presence of Ar, He, N₂, O₂ and C₂H₂, in addition to the reaction rate constant of C₃ (¹∑⁺_g. 000) with C₂H₂ of (2.2 ± 0.20) × 10_-14 cm³ molecule^?1 s^?1.