@article{11983, author = {A. Kortyna and David Nesbitt}, title = {High-resolution infrared spectroscopy of jet cooled trans-deuteroxycarbonyl (trans-DOCO) radical}, abstract = {The rovibrational spectrum of jet cooledtrans-deuteroxycarbonyl (trans-DOCO) radical has been explored at suppressed-Doppler resolution via direct infrared absorption spectroscopy. The trans-DOCO is produced in a supersonic slit discharge of rare-gas/CO mixture doped with D2O, whereby the OD forms an energized adduct with CO, cooling in the supersonic expansion and stabilizing DOCO in the trans well. Active laser-frequency stabilization and collisional quenching of Doppler broadening along the slit axis yield \<10 MHz frequency precision, with the absorbance noise approaching the quantum shot-noise limit. The current high-resolution spectral results are in excellent agreement with recent studies of the trans-DOCO radical by infrared frequency comb spectroscopy under room temperature conditions [Bui et al., Mol. Phys. 116, 3710 (2018)]. Combined with previous microwave/millimeter wave rotational studies, the suppressed-Doppler infrared data permit characterization of the vibrational ground state, improved structural parameters for the OD stretch vibrational level, andtrans-DOCO spin-rotation information in both ground and excited vibrational states. Additionally, the infrared data reveal a-type and much weaker b-type contributions to the spectrum, analysis of which yields orientation of the OD stretch transition dipole moment in the body fixed frame. Of dynamical interest is whether the nascent\ trans-DOCO complex formed in the entrance channel has sufficient time to convert into the\ cis-DOCO isomer, or whether this is quenched by rapid stabilization into thetrans-DOCO well. Ab initio and Rice-Ramsperger-Kassel-Marcus analysis of the intrinsic reaction coordinate fortrans-DOCO to cis-DOCO interconversion rates supports the latter scenario, which helps explain the failure of previous high resolution infrared efforts to detect cis-hydroxycarbonyl.

}, year = {2019}, journal = {The Journal of Chemical Physics}, volume = {150}, pages = {194304}, month = {2019-05}, issn = {0021-9606}, url = {https://aip.scitation.org/doi/10.1063/1.5092599}, doi = {10.1063/1.5092599}, }