Rotational spectra and structures of the small clusters Ar/sub 3/-HF and Ar/sub 3/-DF

Journal Article · Wed Sep 16 04:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00253a012· OSTI ID:5954621

S, Gutowsky H; Klots, T D; Chuang, C; Keen, J D; Schmuttenmaer, C A; Emilsson, T

Microwave rotational spectra have been observed for the two small clusters /sup 40/Ar/sub 3/-HF and /sup 40/Ar/sub 3/-DF, the first clusters to be so characterized. Their detection was made possible by sensitivity improvements to a Flygare spectrometer, which uses Fourier transform operation of a Fabry-Perot microwave cavity in conjunction with a pulsed supersonic nozzle to generate the clusters. The symmetric top transitions measured for J = 1 ..-->.. 2 to J = 6 ..-->.. 7 are fitted by rotational constants B/sub 0/, D/sub J/, and D/sub JK/ of 1188.212 MHz, 6.85 kHz, and -5.76 kHz for Ar/sub 3/-HF and of 1180.379 MHz, 6.57 kHz, and -5.156 kHz for Ar/sub 3/-DF. The composition and C/sub 3v/, symmetry of the clusters were established by the conditions of their formation, by the hyperfine structure of their transitions, by the absence of K states other than 0, +/- 3, and +/- 6, and by analysis of the values found for B/sub 0/. The H/DF lies along the threefold axis of the Ar/sub 3/ group, with the H/D end closest to Ar/sub 3/. Analysis of the moments of inertia and torsional amplitudes for the two isotopic species gives an approximate Ar/sub 3/ c.m. to HF c.m. distance of 2.735 A and an estimate of 3.835 A for the Ar-Ar distance. Tilt of the Ar/sub 3/ group is considered in the estimate. The Ar to HF c.m. and Ar-Ar distances in the clusters are comparable with those in the Ar/sub 2/ and Ar-HF dimers and Ar/sub 2/-HF trimer. The shape of the interaction potential between Ar/sub 3/ and H/DF is discussed.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5954621
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:19; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADDUCTS
ARGON
ARGON 40
ARGON ISOTOPES
DATA
DEUTERIUM COMPOUNDS
DIMERS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
EVEN-EVEN NUCLEI
EXCITED STATES
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
INTERATOMIC FORCES
ISOTOPES
LIGHT NUCLEI
MICROWAVE RADIATION
MOLECULAR STRUCTURE
NONMETALS
NUCLEI
NUMERICAL DATA
POLYMERS
RADIATIONS
RARE GASES
ROTATIONAL STATES
STABLE ISOTOPES