Terahertz laser spectroscopy of the water dimer intermolecular vibrations. II. (H{sub 2}O){sub 2}

Journal Article · Thu Jun 15 04:00:00 EDT 2000 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.481669· OSTI ID:20216747

Braly, L B ^[1]; Liu, K ^[1]; Brown, M G ^[1]; Keutsch, F N ^[1]; Fellers, R S ^[1]; Saykally, R J ^[1]

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1. Department of Chemistry, University of California, Berkeley, California 94720 (United States)

Terahertz VRT laser spectra of four (H{sub 2}O){sub 2} intermolecular vibrations consisting of 362 transitions have been measured between 87 and 108 cm{sup -1} with ca. 2 MHz precision. The results differ both qualitatively and quantitatively from the predictions of dimer potentials tested. The spectra also reveal an ordering of the intermolecular vibrations which differs dramatically from that predicted by normal mode analysis. Strong coupling is indicated between the low barrier tunneling motions and the intermolecular vibrations as well as among different vibrations. In particular the 102.1 cm{sup -1} (H{sub 2}O){sub 2} vibration assigned as the acceptor wag ({nu}{sub 8}) exhibits two types of perturbations. In one of these a component of K{sub a}=1 coupling with a tunneling component of K{sub a}=0 in the 108 cm{sup -1} acceptor twist ({nu}{sub 11}) vibration. There is also an indication that the 103.1 cm{sup -1} (H{sub 2}O){sub 2} band assigned as the donor in-plane bend ({nu}{sub 6}) is coupled to the acceptor wag resulting in a lower of the in-plane bend frequency and a higher acceptor wag frequency. Detailed analysis of the VRT levels confirms the extreme nonrigidity of this complex, indicating that the use of approximate models with reduced dimensionality to calculate its properties are likely to fail. (c) 2000 American Institute of Physics.

• OSTI ID: 20216747
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 23 Vol. 112; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
DIMERS
ENERGY TRANSFER
EXPERIMENTAL DATA
INFRARED SPECTRA
LASER SPECTROSCOPY
MHZ RANGE 01-100
ROTATIONAL STATES
VIBRATIONAL STATES
WATER