1. Submillimeter-wave lines of H 2 D + and D 2 H + as probes into chemistry in cold dark clouds T. Amano Institute for Astrophysics and Planetary Sciences Ibaraki University

2. In this talk Overview of spectroscopy of D 2 H + and H 2 D + TuFIR lines of H 2 D + H 5 + and its deuterated species

3. Spectroscopy of H 2 D + and D 2 H + Shy, Farley, Wing (1981): Ion beam Shy, Farley, Wing (1981): Ion beam Amano & Watson (1984), Amano (1985): 1 band (H 2 D + ) Amano & Watson (1984), Amano (1985): 1 band (H 2 D + ) Lubic & Amano (1984): 1 band (D 2 H + ) Lubic & Amano (1984): 1 band (D 2 H + ) Foster et al. (1986): 2 / 3 bands (H 2 D + ) Foster et al. (1986): 2 / 3 bands (H 2 D + ) Foster, McKellar, Watson. (1986): 2 / 3 bands (D 2 H + ) Foster, McKellar, Watson. (1986): 2 / 3 bands (D 2 H + ) Polyansky & McKellar (1990): All available data were fitted together to improve molecular constants. (D 2 H + ) Polyansky & McKellar (1990): All available data were fitted together to improve molecular constants. (D 2 H + ) Amano & Hirao, J. Mol. Spectrosc. 233, 7 (2005) IR

4. Bogey et al. (1984): 1 10 -1 11 H 2 D + (372.4 GHz) Bogey et al. (1984): 1 10 -1 11 H 2 D + (372.4 GHz) Warner et al.(1984): Warner et al.(1984): Saito, Kawaguchi, Hirota (1985): 2 20 -2 21 H 2 D + (156.0 GHz) Saito, Kawaguchi, Hirota (1985): 2 20 -2 21 H 2 D + (156.0 GHz) Jennings, Demuynck, Banek, Evenson (unpublished): Jennings, Demuynck, Banek, Evenson (unpublished): 1 01 -0 00 H 2 D + (1370.1 GHz) 1 01 -0 00 H 2 D + (1370.1 GHz) 1 11 -0 00 D 2 H + (1476.6 GHz) 1 11 -0 00 D 2 H + (1476.6 GHz) 2 20 -2 11 D 2 H + (1370.1 GHz) 2 20 -2 11 D 2 H + (1370.1 GHz) Hirao & Amano (2003): 1 10 -1 01 D 2 H + (691.7 GHz) Hirao & Amano (2003): 1 10 -1 01 D 2 H + (691.7 GHz) Amano & Hirao (2005): 3 21 -3 22 H 2 D + (646.4 GHz) Amano & Hirao (2005): 3 21 -3 22 H 2 D + (646.4 GHz) mm-, sub-mm, FIR

5. Theoretical work Carney and Porter(1977) Tennyson, Polyansky and coworkers carried out very high level ab initio calculations, and interactions between theory and experiments were often very crucial in assigning the spectra and in deriving the accurate spectroscopic constants. See for example, Polyansky and Tennyson, JCP,110, 5056(1999) See for example, Polyansky and Tennyson, JCP,110, 5056(1999)

6. Ibaraki sub-mm system Russian BWO(Backward-wave oscillator) 270-860 GHz ~1 mW stabilized, using double phase-lock loop Double modulation technique frequency-discharge frequency-magnetic field extended negative glow discharge

7. Double modulation sub-mm system at Ibaraki (University of Waterloo)

8. Submillimeter-wave system in Ibaraki

9. Extended negative glow discharge source. Extended negative glow discharge source. (Magnetic field: 200G). (Magnetic field: 200G). Double modulation. Double modulation. H 2 /D 2 /Ar = 4 /2 /17 mTorr for H 2 D + H 2 /D 2 /Ar = 4 /2 /17 mTorr for H 2 D + =3 /2 /17 mTorr for D 2 H + =3 /2 /17 mTorr for D 2 H + I = 8 mA, T ~ 77 K I = 8 mA, T ~ 77 K Experimental Details

11. Ap.J. Lett. 597, L85-L87(2003). 691660.440(20) MHz

12. TuFIR Spectrometer ( Toyama University )

13. Energy Level Diagram of H 2 D +

18. Hyperfine structure of H 2 D + and D 2 H + Jensen et al. Mol. Phys. 91, 319(1997) H2D+H2D+ D2H+D2H+ H2D+H2D+

19. Yamaguchi, Gaw, Remington, Schaefer. J. Chem. Phys. 80, 5072(1987) H5+H5+ Xie, Braams, Bowman. J. Chem. Phys.122, 224307(2005)

20. 1-C 2v 2-D 2d 3-C 2v 4-D 2h 4 low energy conformers of H 5 +

21. Financial support Ministry of Education, Science, and Culture of Japan Japan Society for Promotion of Science(JSPS) Japan Space Forum(JSF) JEM/SMILES Project