Far-infrared laser vibration-rotation-tunneling spectroscopy of water clusters in the librational band region of liquid water

Citation
Fn. Keutsch et al., Far-infrared laser vibration-rotation-tunneling spectroscopy of water clusters in the librational band region of liquid water, J CHEM PHYS, 114(9), 2001, pp. 4005-4015
Citations number
44
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CHEMICAL PHYSICS
ISSN journal
00219606 → ACNP
Volume
114
Issue
9
Year of publication
2001
Pages
4005 - 4015
Database
ISI
SICI code
0021-9606(20010301)114:9<4005:FLVSOW>2.0.ZU;2-Y
Abstract
We report the first high resolution spectrum of a librational vibration for a water cluster. Four parallel bands of (H2O)(3) were measured between 510 and 525 cm(-1) using diode laser vibration-rotation-tunneling (VRT) spectr oscopy. The bands lie in the "librational band" region of liquid water and are assigned to the nondegenerate out of plane librational vibration. The o bservation of at least three distinct bands within 8 cm(-1) originating in the vibrational ground state is explained by a dramatically increased split ting of the rovibrational levels relative to the ground state by bifurcatio n tunneling and is indicative of a greatly reduced barrier height in the ex cited state. This tunneling motion is of special significance, as it is the lowest energy pathway for breaking and reforming of hydrogen bonds, a sali ent aspect of liquid water dynamics. (C) 2001 American Institute of Physics .