Fourier transform emission spectroscopy of the B 1Π–X 1Σ+, C 1Σ+–X 1Σ+, and G 1Π–X 1Σ+ systems of ScH and ScD

Abstract

The emission spectra of ScH and ScD have been observed in the 380 nm-2.5 m spectral region using a Fourier transform spectrometer. The molecules were excited in a scandium hollow cathode lamp operated with neon gas and a trace of hydrogen or deuterium. Three transitions with a common lower state, assigned as the ground X 1 ⌺ ϩ state, have been observed in the near infrared and visible regions. The ScH bands with 0-0 band origins at 5404, 13 574, and 20 547 cm Ϫ1 have been assigned as the B 1 ⌸ -X 1 ⌺ ϩ , C 1 ⌺ ϩ -X 1 ⌺ ϩ , and G 1 ⌸ -X 1 ⌺ ϩ transitions, respectively. A rotational analysis of the 0-0, 1-1, 1-0, and 2-1 bands of the B 1 ⌸ -X 1 ⌺ ϩ system, the 0-0 and 1-1 bands of the C 1 ⌺ ϩ -X 1 ⌺ ϩ system and the 0-0 band of the G 1 ⌸ -X 1 ⌺ ϩ system has been obtained. The principal molecular constants for the X 1 ⌺ ϩ state of ScH are ⌬G(1/2)ϭ1546.9730(14) cm Ϫ1 , B e ϭ5.425 432(48) cm Ϫ1 , ␣ e ϭ0.124 802(84) cm Ϫ1 and r e ϭ1.775 427(8) Å. The corresponding band systems of ScD have also been analyzed. A rotational analysis of the 0-0, 1-1, and 1-0 bands of the B 1 ⌸ -X 1 ⌺ ϩ system, the 0-0, 1-1, 0-1, and 1-2 bands of the C 1 ⌺ ϩ -X 1 ⌺ ϩ system and the 0-0 band of the G 1 ⌸ -X 1 ⌺ ϩ system has been obtained. The equilibrium molecular constants determined for the ground state of ScD are e ϭ1141.2650 (31) cm Ϫ1 , e x e ϭ12.3799(15) cm Ϫ1 , B e ϭ2.787 432(41) cm Ϫ1 , ␣ e ϭ0.045 321(73) cm Ϫ1 , and r e ϭ1.771 219(13) Å. The ScH assignments are supported by recent theoretical predictions made by Anglada et al. ͓Mol. Phys. 66, 541 ͑1989͔͒ as well as the experimental results available for ScF and the isovalent YH and LaH molecules. Although some unassigned bands have been attributed to ScH and ScD by previous workers, there have been no previous analyses of ScH or ScD spectra.

Fourier Transform Emission Spectroscopy of ScH and ScD: The New Singlet Electronic StatesA1Δ,D1Π,E1Δ, andF1Σ−

“…The corThe uncertainty of measurements of the weaker and responding ScD bands have also been analyzed (14). The blended lines are, however, expected to be somewhat larger present paper deals with rotational analysis of the new transidepending on the signal-to-noise ratio, the extent of blend-tions…”

“…Copyright ᭧ 1997 by Academic Press (14). The corThe uncertainty of measurements of the weaker and responding ScD bands have also been analyzed (14).…”

“…The measurements of the Ne atomic lines made by Palmer The experimental details were provided in our previous and Engleman ( 16 ) have been used for calibration of our paper (14). Briefly, the bands were excited in a scandium ScH and ScD spectra.…”

“…Since ScH is the simplest transition-metal-containing molecule, there have been a large number of theoretical calculations of the spectroscopic properties of ScH (8)(9)(10)(11)(12)(13) bands of ScH and ScD in the 4000-21 000 cm 01 region (14). These bands were classified into three electronic tranhollow cathode lamp and the spectra were recorded at 0.02 sitions, The spectral line positions were of the complex bands remained unclassified because of their extracted from the observed spectra using a data reduction weaker intensity, overlapping lines, and perturbations.…”

Laser-Induced Fluorescence Molecular Beam Investigation of New Singlet and Triplet Electronic States of Yttrium Monohydride

“…The ab initio prediction was experimentally confirmed in our laboratory in the earliest stage of the present project (15) as several transitions originating from a 1 + but none from a 3 lower state were observed in the jet-cooled spectra. Following the successful reassignment of the symmetry of the ground state of YH to 1 + the ground states of ScH (16) and LaH (17) were also revised by Ram and Bernath to be 1 + . Ram and Bernath have also studied YH (18) and YD (19) isotopomers by Fourier transform emission spectroscopy.…”