Excited-state dynamics of CH2CHO ((B)over-tilde(2)A'')

State-specific radiative lifetimes and electronic quenching cross sections are reported for four different vibrational modes of CH2CHO ((B) over tilde(2)A''). Ground-state vinery radicals are produced by 193-nm excimer laser photolysis of CH3OCH=CH2, and pumped to the (B) over tilde state by a tunable dye laser operating between 332 and 348 nm. Fluorescence decay rates are determined in the presence of 12 collision partners: He, Ar, N-2, O-2, CO, H-2, HCl, N2O, CO2, C2H4, CH3OCH=CH2, and SF6. The measured electronic quenching cross sections vary from 0.01 to 66.5 Angstrom(2). Zero pressure radiative lifetimes are found to vary from 98 +/- 10 to 154 +/- 18 ns, depending on the vibrational mode. Possible mechanisms for lifetime shortening and collisional quenching are discussed.