Toichi Konno

Infrared diode laser spectroscopy of a high-temperature molecule: GeSe

Abstract The vibrational-rotational spectrum of GeSe has been observed with diode laser spectrometer equipped with a single pass cell of heat-pipe oven type. About 770 spectral lines for the Δv = 1 band sequences of six isotopomers of GeSe have been assigned between 380 to 420 cm −1 . These data have been analyzed in combination with 138 microwave data from the literature by two different methods of least-squares fit to different potential functions. The qualities of the fits are nearly equal. The value of ω e is determined to be 402.66129(70) cm −1 for 74 Ge 80 Se.

Infrared diode laser spectroscopy of a high-temperature molecule GeS using spectrum processing by fourier transformation

Abstract The vibrational-rotational spectrum of GeS has been observed using a diode laser spectrometer equipped with a heatpipe high-temperature cell of a White cell type. Fringes due to optical reflections inside the high-temperature White cell were inherent in the observation of the spectra. However, they were eliminated, as were high-frequency noises, by Fourier manipulation of the observed diode laser spectrum. About 620 spectral lines for the Δv = 1 band sequences of the eight isotopomers, 74Ge32S, 72Ge32S, 70Ge32S, 73Ge32S, 76Ge32S, 74Ge34S, 72Ge34S and 70Ge34S have been assigned between 522 and 593 cm−1. These infrared data combined with 91 microwave data from the literature have been analyzed with a least-squares fit to a Dunham potential function with only 11 parameters which included three Watson type Δ correction terms. The Dunham Yij coefficients have been derived for each of the eight isotopomers. The equilibrium vibrational frequency ωe of 74Ge32S is 574.269 313(271) cm−1.

Infrared emission spectrum of AlBr

Abstract An infrared emission spectrum of the Δν=1 bands of AlBr has been observed with a Fourier transform spectrometer with 0.1 cm −1 resolution. The ν=1-0 to 3-2 and ν=5-4 vibration-rotation bands of Al 79 Br and the ν=1-0 to 5-4 bands of Al 81 Br were assigned in the wavenumber range between 310 and 400 cm −1 . The infrared data combined with millimeter-wave data from the literature were analyzed with a least-squares fit to a Dunham potential function with only seven parameters. Thirteen Dunham Y ij coefficients have been derived for each of the isotopic species.

Infrared diode laser spectroscopy of high-temperature molecules using spectrum processing by Fourier transformation

Abstract A heat-pipe high-temperature cell of the White cell type was constructed for sensitive detection of the spectra of high-temperature molecules. It has been incorporated into the optical system of a tunable diode laser spectrometer. With a 40 m optical path length abundant spectral lines of the Δν=2 vibration—rotation bands of NaBr have been observed in the wavenumber range between 560 and 600 cm −1 . The technique of spectrum processing by use of Fourier transformation was applied to the source-modulated diode laser spectrum to eliminate fringes and to improve the signal-to-noise ratio.

Far infrared emission spectroscopy of KCl

Abstract Far infrared emission spectrum of Δ v =1 bands of KCl has been observed in the range from 230 to 295 cm −1 with a resolution of 0.1 cm −1 . Vibration-rotation transitions of the 1-0, 2-1, 3-2 and 4-3 bands of K 35 Cl were analyzed by a single least-squares fit to a set of seven Dunham coefficients Y ij . Y 10 and Y 20 for K 35 Cl were determined to be 279.963 (22) cm −1 and −1.2306(83) cm −1 , respectively, with the standard errors in parentheses. Characteristic features of the far infrared emission spectroscopy of high-temperature molecules have been discussed.

Infrared absorption spectroscopy of Ar-12C18O2 : change in the intramolecular potential upon complex formation

Abstract An infrared absorption spectrum has been observed and analyzed for an Ar– 12 C 18 O 2 van der Waals (vdW) complex in the range of 2312–2314 cm −1 . The effective structure of the complex derived from the obtained rotational constants is in essential agreement with the structure estimated from that of Ar– 12 C 16 O 2 based on the isotope effect on the amplitudes of vdW vibrations. The band origin for the Ar– 12 C 18 O 2 ν 4 mode shows a red shift of 0.4567 cm −1 with respect to that for 12 C 18 O 2 ν 3 mode; the change in the intramolecular potential of CO 2 upon complex formation with Ar is determined from the isotope effect on the band-origin shift.

Infrared spectrum and fourier transform spectroscopy of the 2ν1 band of OCSe: Synthesized by using a heat pipe reactor

Abstract In order to observe the infrared spectrum of OCSe, a sufficient amount was readily synthesized by using a heat pipe reactor. Thirteen vibrational bands were observed in the region of 400 ∼ 4000 cm −1 , seven of which have never been reported. The high-resolution FTIR spectrum of the 2 ν 1 band of OCSe was recorded with a resolution of 0.005 cm −1 . Analysis provided molecular constants for the 2 ν 1 band of 16 O 12 C 80 Se and 16 O 12 C 78 Se in natural abundance.

Infrared diode laser spectroscopy of BrF and BrCl

Abstract Diode laser spectra of BrF and BrCl below 700 cm −1 were observed and analyzed. Transitions in the 1-0 and 2-1 bands of 79 BrF and 81 BrF and those in the 1-0, 2-1, and 3-2 bands of 79 Br 35 Cl, 81 Br 35 Cl, 79 Br 37 Cl, and 81 Br 37 Cl were fitted to seven and eight Dunham coefficients, respectively. Many BrCl lines, which can be used for wavenumber calibration of diode laser spectra, were obtained between 400 and 450 cm −1 with an accuracy of about 0.001 cm −1 .

Infrared emission spectrum of NaBr

Abstract The infrared emission spectrum of Δν = 1 bands of NaBr monomer has been observed with a Fourier transform spectrometer. The ν= 1-0 to 5-4 vibration—rotation bands for both Na 79 Br and Na 81 Br were assigned in the wavenumber range between 225 and 315 cm −1 . These infrared data combined with millimeter-wave data from the literature were analyzed with a least-squares fit to a Dunham potential function with only seven parameters. ω e (Na 79 Br) has been determined to be 298.7377 (43) cm −1 with one standard error in parentheses. Thirteen Dunham Y ij coefficients have been derived for each of the two isotopic species from the Dunham potential function.

Analysis of vibration-rotational spectra of KH

Abstract A modified Dunham potential model developed recently was applied to the analysis of vibration-rotational spectra of KH. The spectral data set consisted of 107 lines from the literature and an additional 12 lines measured in the present study. In total 119 spectral lines for four isotopomers were simultaneously fitted to a single set of only 11 molecular parameters, U ω , U B , a 1 , a 2 , a 3 , a 4 , a 5 , Δ H ω , Δ H B , r H 0 and Δ H al , well within experimental errors. Values of ω e ( 39 KH ) and r e within the Born-Oppenheimer approximation are 986.6484(41) cm −1 and 224.0164(10) pm, respectively, assuming that Δ K ω and Δ K B are equal to zero.