Measurement of the intermolecular vibration--rotation tunneling spectrum of the ammonia dimer by tunable far infrared laser spectroscopy

Journal Article · Mon Apr 01 00:00:00 EST 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.460562· OSTI ID:5882345

Havenith, M; Cohen, R C; Busarow, K L; Gwo, D; Lee, Y T; Saykally, R J ^[1]

---

1. Department of Chemistry, University of California, and Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory Berkeley, California 94720 (USA)

Over 150 lines in six tunneling subbands of an intermolecular vibration located near 25 cm{sup {minus}1} have been measured with partial hyperfine resolution and assigned to (NH{sub 3}){sub 2}. The transitions sample all three types of tunneling states ({ital A}, {ital G}, {ital E}) and are consistent with the following assumptions: (1) G{sub 36} is the appropriate molecular symmetry group; (2) the equilibrium structure contains a plane of symmetry; (3) interchange tunneling of inequivalent monomers occurs via a {ital trans} path; (4) the 2C{sub 3}+I limit of hydrogen exchange tunneling is appropriate; (5) tunneling and rotational motions are separable. A qualitative vibration--rotation tunneling energy level diagram is presented. Strong perturbations are observed among the states of {ital E} symmetry. This work supports the conclusions of Nelson {ital et} {ital al}. (J. Chem. Phys. {bold 87}, 6365 (1987)).

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5882345
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 94:7; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMMONIA
DIMERS
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
FAR INFRARED RADIATION
HYDRIDES
HYDROGEN COMPOUNDS
INFRARED RADIATION
INFRARED SPECTRA
LASER SPECTROSCOPY
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
RADIATIONS
ROTATIONAL STATES
SPECTRA
SPECTROSCOPY
TUNNELING
VIBRATIONAL STATES