Spectroscopic Study of the B 1Π State of NaH

Chia-Ching Chu; Chun Huang; Chin-Chun Tsai; Thou-Jen Whang

doi:10.1021/acsomega.1c02767

Spectroscopic Study of the B ¹Π State of NaH

ACS Omega. 2021 Jul 28;6(31):20629-20636. doi: 10.1021/acsomega.1c02767. eCollection 2021 Aug 10.

Authors

Chia-Ching Chu¹, Chun Huang¹, Chin-Chun Tsai², Thou-Jen Whang¹

Affiliations

¹ Department of Chemistry, National Cheng Kung University, Tainan 70101, Taiwan.
² Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.

Abstract

In this study, the B ¹Π excited state of NaH has been experimentally studied for the first time. Pulsed laser-induced fluorescence excitation spectroscopy was used to investigate the B ¹Π electronic state of NaH. A total of 48 ro-vibronic transitions were observed, including within the B-X (0-0) and B-X (0-1) transition bands. Only one B-state vibrational level was identified, and a series of PQR lines, with eight e-parity and eight f-parity sublevels (v' = 0, J' = 1-8), were assigned. The level assignment was supported by a comparison of the experimental line positions with the ab initio calculations, the dispersed laser-induced fluorescence spectrum of the NaH B ¹Π → X ¹∑⁺ emission, and the V-type optical-optical double resonance spectra. The Dunham-type coefficients, the mean internuclear distance, the harmonic vibrational frequency ω, and the dissociation energies D ₀ and D _e of the B ¹Π state were determined.