PHOFEX Spectroscopy of HgNe and HgAr: Determination of the Dissociation Energies of the X<sup>1</sup>Σ<sup>+</sup>, A<sup>3</sup>Π<sub>0<sup>+</sup></sub>, and B<sup>3</sup>Π<sub>1</sub>States
作者:Tomoki Tasaka、Ken Onda、Akiyoshi Hishikawa、Kaoru Yamanouchi
DOI:10.1246/bcsj.70.1039
日期:1997.5
Photofragment excitation (PHOFEX) spectroscopy was applied to determine the dissociation energies of the B3Π1 states of HgAr and HgNe. The PHOFEX spectra were measured in the wavelength region where the laser-induced fluorescence spectrum of the B3Π1–X1Σ+ transition exhibits a continuum structure by probing the photolysis product of Hg(63P1) through the Hg(83S1–63P1) transition. By the spectral simulation of the threshold behavior of the high-resolution (Δν ≈ 0.08 cm−1) PHOFEX spectrum, the thresholds for the photodissociation reaction, HgRg → Hg(63P1) + Rg, were determined to be 39447.9(3) and 39536.0(5) cm−1 for Rg = Ne and Ar, respectively. From these thresholds, the dissociation energies, D0’s, of the B3Π1 states of HgNe and HgAr were determined to be D0(B3Π1; HgNe) = 9.8(3) and D0(B3π1; HgAr) = 61.8(5) cm−1, respectively. This direct determination of the dissociation energies of the B3Π1 states led to a determination of the D0’s for the X1Σ+ and A3Π0+ states; D0(X1Σ+; HgNe) = 35.6(3), D0(X1Σ+; HgAr) = 123.7(5), D0(A3Π0+; HgNe) = 68.7(3), and D0(A3Π0+; HgAr) = 348.8(6) cm−1. In addition, the (v′,0) vibronic bands of the B3Π1–X1Σ+ transition of HgAr were re-measured with high resolution for v′ = 0—8. From the transition wavenumbers of these vibronic bands, the Morse potential parameters were determined with high precision as ωe = 11.94(3) cm−1 and ωexe = 0.594(3) cm−1.