1. Millimeter-wave Spectroscopy of the Tunneling-rotation Transitions of the D 2 CCD radical M. Ohtsuki, M. Hayashi, K. Harada, K. Tanaka Department of Chemistry, Faculty of Sciences, Kyushu University International Symposium on Molecular Spectroscopy 63 rd –Meeting The Ohio State University

2. Introduction C C H HH C C H H H α H 2 CCH  E 0 = 16.271 GHz h = 1580 cm -1 J. Chem. Phys. 120, 3604 (2004) Previous Work  H 2 CCD  E 0 = 1.186 GHz h = 1520 cm -1 D D D 2 CCD  E 0 = ? h = ? Present Work D D D D E0E0 h  E 0 :Tunneling splitting h:Potential Barrier height 0+0+ 00 h < 1800 cm -1

3. 0 00 1 01 2 02 3 03 2 11 2 12 1 10 1 11 0 00 1 01 2 02 3 03 2 11 2 12 1 10 1 11 K a = 0 K a = 1 K a = 0 K a = 1 0+0+ 00 N KaKcKaKc a-type transition E. Kim, et al., J.C.P 116, 10713(2002) E0E0 CC DD DD DD a b Introduction -Pure rotatonal Transition-  a =  0.1611 D para ortho

4. b-type transition R(0) Q(1) R(1) E0E0 CC DD DD DD a b 0 00 1 01 2 02 3 03 2 11 2 12 1 10 1 11 0 00 1 01 2 02 3 03 2 11 2 12 1 10 1 11 K a = 0 K a = 1 K a = 0 K a = 1 0+0+ 00 Introduction -Tunneling-rotation Transition-  b =  0.5863 D para ortho

5. UV laser 193 nm Sample (Ar : 7 atm + H 2 : 3 atm) + D 2 CCDCl : 0.2 atm CC D D D Cl Photolysis ArF Experimental setup T rot =20 K CC D D D D DD CC Millimeter-wave 100 ~ 200 GHz White-type multi-reflection cell (10 round trips)

6. Obs. 143.5143.55143.45 Frequency(MHz) Observed Tunneling-rotation Spectra R(0)(0  ←0 + ) J :0.5 ←0.5 J :1.5 ←0.5 Para:I  =1 Calc.

7. N S F F1F1 J II II N : Rotation S : Electron spin I : Nuclear spin Coupling of Angular Momenta (0  )1 11 -(0 + )0 00 I  = 1 C D C D D S = 0.5 I  = 0,1,2 S II II Para : I  =1 Ortho : I  =0,2

8. Ortho:I  = 0,2 Observed Tunneling-rotation Spectra R(0)(0  ←0  ) Obs. J :0.5 ←0.5J :1.5 ←0.5 142.00141.90 (GHz) 141.95 Calc. I  = 2 Calc. I  = 0

9. Frequency (GHz) Q(1) R(0) R(1) Q(2) 120 100 160 180 2E02E0 140 GHz (0 + ←0 - ) (0 - ←0 + ) 1.54GHz 140 Q(3) Observed Tunneling-rotation Spectra 00 0+0+ E0E0 6:36:3 6:36:3 ortho 200 para

10. Constants (MHz) (average)FTMW (MHz) (average) E0 E0 771.858 (24)  A122 560.835 (50)  B 24 264.477 (38)(B + C)/2 = 22 220.523 32(25) C 20 175.989 (38)  aa 120.666 (24)    bb +  cc )/2  24.11 (33)  24.095 1(19) a F (  ) 5.872 (11) 5.874 5(27) T aa(  ) 4.130 (14) 4.123 5(42) T bb(  ) 0.97 (11)  a F (  ) 21.617 (32) 21.608 7(111) T aa(  ) 1.302 9 (80) 1.293 5(23) T bb(  )  0.274 (56)   a F (  ) 8.5 (13)   = 160.8kHz Data:93 ( MMW(61) + FTMW(32)) Molecular Constants Off-diagonal Fermi interaction constant average : (0 + + 0  ) / 2

11. Potential Barrier Height C C D DD C C D D D  min  43.4   E 0 (MHz) h (cm -1 ) D 2 CCD 771.858 (24) 1549 H 2 CCD1 186.820 (21)1520 H 2 CCH16 271.842 9(59)1580 V(  ) =  V 2  2 + V 4  4 h = V22V22 4V 4 *  min is fixed (CCSD(T)/TZ2P) (Chem. Phys.206, 43 (1996)) E0E0 h  0+0+ 00  min

12. Ortho-Para Interaction 0 00 1 01 1 10 1 11 0 00 1 01 1 10 1 11 K a = 0 K a = 1 K a = 0 K a = 1 0+0+ 00 paraortho para ortho R(0) Tunneling-rotation Transitions (  I  = 0) Ortho-Para Interaction (  I  = 1) Ortho (I  = 0, 2) Para ( I  = 1)  E 0 = 771MHz  = 0.094 MHz  =  0.094 MHz + + + +     1 2 aF S IaF S I H F  =

13. ortho-para interaction a F  = (a F  + a F  )/2  a F  = a F   a F   I  = I   I  (MHz)D 2 CCDH 2 CCD  a F  8.5 (13)67.14 (67)   771.858 (24)1 186.820 (21)  (interaction) 0.0940.94   (mixing ratio) 0.012 %0.080 % I  = I   I  Ortho-Para Interaction (  I  = 1)   0 + (1 11 ) 0  (1 11 ) H F (  ) = a F (  ) S I  + a F (  ) S I  = a F (  ) S  I  + (  a F (  ) S  I  )/2

14. ○ Tunneling-rotation Transition of D 2 CCD radical was observed and assigned. ○ Tunneling splitting (  E 0 ) was determined to be 771.858 (24) MHz. ○ Potential barrier height(h) was estimated to be 1549 cm  1. Conclusions ○ Off-diagonal Fermi interaction term  a F , was determined to be 8.5 (13) MHz at D 2 CCD.

15. Thank you for your attention!!

16. B.E.Turner,et al,. ApJ. 561. L207.2001. Sagittarius B2(N) Introduction -Observation at Interstellar region- H O C H C H H Vinyl alcohol

17. Horse head Nebula at Orion [DCO + ]/[HCO + ] ≧ 0.02[ND 3 ]/[NH 3 ] ≒ 10 -3 ⇒ Deuterium condensation Deuterium Condensation DCO + is 10 3 times ND 3 is 10 11 times D/H =10   Generally  D 2 CCD radical is able to be observed Interstellar region 1856.06 cm  1 H 2 CCH D 2 CCD 2650 K Zero point energy

18. B3LYP/6-31++G(d,p)(Basiuk, V. A. et al. IJQC, 97, 713(2004)) TS 0 (kcal/mol) -140.1 -279.6 -278.2 -326.3 -436.3 1.6 kcal/mol -218.2 -318.0 +OH +H C C C H C O C H C H O C H C H H H O C H C H H Vinyl alcohol Sagittarius B2(N) Example -Calculation for Energy Diagram- C 2 H 2 + H → H 2 CCH This reaction is inhibited by potential barrier at 4K. C H C H H C H C H Vinyl will be formed in hot molecular cloud or at surface of dust.

19. Experiment D C D C D Cl D C D C D D C D C D Vinyl-d 3 chloride Vinyl-d 3 radical ○ Vinyl radical was produced by 193 nm excimer laser photolysis in the supersonic jet. ○ Millimeter-wave goes ten round trip in the white type cell. ○ Rotational temperature is estimated to be 20 K. ○ Frequency region is between 100 GHz and 200 GHz. Photolysis Ar-F :193nm

20. Obs. J :0.5 ←0.5 J :1.5 ←0.5 143500143550143450 Frequency(MHz) Observed Tunneling Rotation Spectra Para:I  =1 R(0)(0  ←0 + )

21. Frequency (MHz) 143460143500143540 Experiment’s Result -R(0) (0  ←0  )- Only signals of D 2 CCD Simulation Including a precursors Precursors

22. 100200300GHz C H C H H Q-branch R-branch C D C H H C D C D D Observed Spectra 2E02E0 2E02E0 2E02E0 32.5 GHz 2.3 GHz 1.54 GHz 0+←00+←0 0←00←0

23. The signal of product by Photolysis Excimer laser / Off Excimer laser / On UV laser 193 nm Precursor 0 123 (ms) Excimer laser / On and Off 400ms Time resolved signal If the signal is precursor → Signal is appeared every time If the signal is product → Excimer laser is on → There is a signal !! Excimer laser is off → There is no signal !!

24. Nuclear spin of Deuteron I = 1 → Boson Ψ=ψeψvψrψnΨ=ψeψvψrψn CC D D D a b  position  position KaKa ψeψe ψvψv ψrψr ψnψn Ψ 0+0+ evenassas para oddasass ortho 0-0- evenaasss ortho oddaaaas para C 2v (M) X 2 B 2 Bose-Einstein statistics I  =0, 2 I  =1 Nuclear spin statistics

25. Discussion -Potential Barrier- V(  ) =  V 2  2 + V 4  4 h = V22V22 4V 4 ※ Structure parameter is fixed by CCSD(T) calculation D 2 CCD H 2 CCD H 2 CCH Potential Barrier (cm -1 ) 1549 1520 1580  E 0 (MHz) Tunneling( /ns) 771.844 (23)1.296 1 163.845 (16)0.859 16 271.842 9 (59)0.061 0+0+ 0   min 00 h  C C D D D D 2 CCD H 2 CCD H 2 CCH

26. Potential barrier height C C H HH C C H H H C C H HH R(CC) = 1.304 + 0.017429  2 R(CH  ) = 1.064 + 0.0244  2 R(CH  ) =1.089  0.0033   0.0061  2 R(CH  ) =1.089 + 0.0033   0.0061  2 ∠ CCH  = 122.2 + 0.594081   0.95858  2 ∠ CCH  = 122.2  0.594081   0.95858  2 ※ Structure parameter is fixed by CCSD(T) calculation CCSD(T)/TZ2P:(Chem. Phys. 206, 43 (1996))  C C H H H   min 

27. Fermi contact interaction constants D 2 CCDH 2 CCH a F  ) (MHz) 21.594 (28)143.353 (40) a F (  ) (MHz) 5.879 9 (70)37.019 2(120) a F (  )D / a F (  )H  a F (  )D / a F (  )H 0.158 84 (20) = 0.153 5 II I 8 3  g s   (0) | 2 a F = a F (  )H a F (  )D = IDID IDID IHIH IHIH

28. 69.58 (48) 142.96 (12) Present aF()aF() da F (  ) H 2 CCD S  I  S I  (MHz) Ar Matrix 73.7 147.8 69.58 (48) 142.96 (12) Present aF()aF() aF()aF() H 2 CCD S  I  S I  (MHz) Ar Matrix 73.7 147.8 19.8(30) 21.594 (28) Present aF()aF() aF()aF() D 2 CCD S・IS・I S I  (MHz) Ar Matrix 11.3 21.7 Fermi contact interaction constants H trans H cis C C HH Ar ESR (JACS. 94, 5950 (1972))    a F = a F trans - a F cis a F = (a F trans ＋ a F cis )/2

29.  cc / C (×10 -3 ) H 2 CCH  D 2 CCD  1.194(36) Discussion -Molecular Constants-  H 2 CCD C H C H H C D C H H C D C D D c c c a a a About c-axis Mass of atom has little influence to the c-axis. → c-axis is out-of-plane, so angle between c-axis and C=C bond is not changed. About a-axis Mass of atom has influence to the a-axis. → a-axis is in-plane, so angle between a-axis and C=C bond is changed. The ratio is matched in 3 

30. Constants (MHz) (a) : (dif)FTMW (MHz) (b) (dif) A-3.7  B-0.52422(B + C)/2  0.523 32(49) C-0.52422  aa 0   bb +  cc )/2 -0.023 3  0.002 3(39) a F (  ) 0.001 20.001 2(54) T aa(  ) -0.013 6  0.013 6 (84) T bb(  ) 0  a F (  ) -0.027 6  0.027 6(224) T aa(  ) -0.011  0.001 1(47) T bb(  ) 0   aa(  ) 0  Fixed Parameter (a)Fixed Parameter (b)Observed