Transient infrared absorption spectrum of the ν1 fundamental of trans-DOCO

Using infrared (IR) difference-frequency laser spectroscopy and 193 nm photolysis of acrylic acid(OD), the rotation–vibration spectrum of the ν1 O–D stretching fundamental of trans-DOCO radical has been recorded and assigned. The assignment of the spectrum is based on the +0.9% gas phase-argon matrix shift of the band origins, on the H/D isotopic shifts of the frequencies, and on the chemical reaction rate with O2. The rotational constants confirm that the spectrum is due to the planar trans isomer. The band center is ν0=2684.102 cm−1. Perturbations are observed in the Ka=1 and 6 levels, and information is obtained about the interacting states.