1. Tunneling splittings in PH3+ and AsH3+ studied by zero-kinetic energy (ZEKE) photoelectron spectroscopy
Yuxiang Mo
Department of Physics,
Tsinghua University, Beijing

2. Inverting vibration of NH3
Potential tunneling splitting
From P. B. Bernath, Spectra of Atoms and Molecules,Oxford Uni. Press, 1995
Energy-level diagram for the inverting NH3

3. NH3+, Planar equilibrium structurex H H x H
(Å)

4. Tunnel splitting P+
PH3

5. Knowledge about PH3+(X) K. Siegbahn and co-workers, Mol. Phys
No energy level splitting found!
Photoelectron spectroscopy

6. Zero kinetic energy photoelectron (ZEKE) spectra
Vibrational states
I(e-)
ZEKE spectrum
Rydberg series converging to vibrational levels of ion

7. Experimental set up THG SHG w1 Dye laser I w2 2w1+w2 Dye laser II YAG
Pulsed nozzle I
(rare gas)
Monochromator
Chamber w1
grating
Pulsed nozzle II
(sample gases)
Dye laser I w2
Dye laser II
Dichroic
mirror
2w1+w2
Mixing Chamber
(four-wave mixing)
MCP
Beam source
Chamber
YAG
Ionization
Chamber

8. PFI-ZEKE spectrum of PH3, first vibrational band
First vibrational energy spliting,

9. PH3+ inverting vibrationα r

10. ZEKE spectra

11. Summary about
Rotationally resolved spectra have been obtained from the vibrational ground state to cm-1 above.
Tunnel splitting has been observed.

12. How about AsH3+

13. Photoelectron spectra vs. ZEKE spectra of AsH3
PES from: Potts and Price, Proc. R. Soc. A 326,181 (1972).

14. ZEKE spectra of AsH3

15. ZEKE spectra of AsH3, Hot band,
AsH3+(v2)AsH3(v2=1)

16. ZEKE spectra of AsH3: examples

17. Potential energy curve of AsH3+

18. Comparisons between the theory and experiments
Vibrational number
Exp.
Cal.
Cal.d
0(0+)
1(0-)
0.8
1.2
0.01
2(1+)
605.5
602.1
632.0
3(1-)
643.2
639.4
632.3
4(2+)
1054.3
1046.8
1226.7
5(2-)
1272.7
1265.5
1233.8
6(3+)
1621.1
1612.3
1730.9
7(3-)
1977.2
1965.9
1808.3
8(4+)
2362.4
2353.6
2157.8
9(4-)
2772.7
2761.4
2393.9

19. Tunneling splittings in PH3+, AsH3+ and SbH3+
Summary:
Tunneling splittings in PH3+, AsH3+ and SbH3+
PH3+
AsH3+
SbH3+
Barrier Heigh
Barrier (cm-1)
1053
1292
2210
Vibrational energy splitting
0+/0-
5.8 (5.8)
1.2(0.8)
0.01
1+/1-
114.9(112.0)
37.3(37.7)
0.3
2+/2-
339.5(336.6)
218.7(218.4)
7.1

20. J. Chem. Phys. in press, 2016

21. 致谢 孙伟
戴足阳 李华
周义勇
2014,Beijing 邵卓
高书敏
徐西玲

22. Thanks！