The Manifestations of "l-Doubling" in Gas-Phase Rotational Dynamics

J Phys Chem Lett. 2024 Dec 19;15(50):12449-12454. doi: 10.1021/acs.jpclett.4c02918. Epub 2024 Dec 12.

Abstract

The "l-Doubling" phenomenon emanates from the coupling between molecular rotations and perpendicular vibrations (bending modes) in polyatomic molecules. This elusive phenomenon has been largely discarded in laser-induced molecular alignment. Here we explore and unveil the ramifications of l-Doubling on the coherent rotational dynamics of linear triatomic molecules at ambient temperatures and above. The observed l-Doubling dynamics may be wrongly considered as collisional decay throughout the first few hundreds of picoseconds past excitation, highlighting the importance of correct assimilation of l-Doubling in current research of dissipative rotational dynamics and in coherent rotational dynamics in general.