Mid-Infrared Signatures of Hydroxyl Containing Water Clusters: Infrared Laser Stark Spectroscopy of OH-H2O and OH(D2O)n (n=1-3)

F. HERNÁNDEZ; J. T. BRICE; C. M. LEAVITT; T. LIANG; P. RASTON; G. A. PINO; G. E. DOUBERLY

AMER INST PHYSICS

Lugar: Melville; Año: 2015 vol. 143 p. 1643041 - 1643041

mall water clusters containing a single hydroxyl radical are synthesized in liquid heliumdroplets. The OHH2O and OH(D2O)n clusters (𝑛 = 1 − 3) are probed with infrared laserspectroscopy in the vicinity of the hydroxyl radical OH stretch vibration. Experimental bandorigins are qualitatively consistent with ab initio calculations of the global minimum structures;however, frequency shifts from isolated OH are significantly over-predicted by both B3LYP andMP2 methods. An effective Hamiltonian that accounts for partial quenching of electronicangular momentum is used to analyze Stark spectra of the OHH2O and OHD2O binarycomplexes, revealing a 3.70(5) Debye permanent electric dipole moment. Computations of thedipole moment are in good agreement with experiment when large-amplitude vibrationalaveraging is taken into account. Polarization spectroscopy is employed to characterize twovibrational ban