Lifetime measurements on single vibrational levels of C2(d 3Πg) by laser fluorescence excitation

The radiative lifetimes of the six lowest vibrational levels of C₂(d ³Π_g) were obtained from decay time studies of the C₂(d ³Π_g → a ³Π_u) Swan band fluorescence excited by a pulsed tunable dye laser. The lifetime was found to be 120 ± 10 ns, independent of the vibrational level. From the experimental results the dependence of the electronic transition moment on the internuclear distance was derived.