1. Rotational Spectra of N 2 O-H 2 Complexes University of Alberta Jen Nicole Landry and Wolfgang Jäger June 23, 2005

2. 2 Motivation Stepping stone for the study of larger N 2 O-(H 2 ) N clusters. Possible observation of superfluidity in N 2 O-(pH 2 ) N. Previous studies:  N 2 O-He and N 2 O-H 2 in the infrared region 1,2.  N 2 O-He in the microwave region 3. 1 Tang & McKellar, JCP 117, 2586 (2002); 2 Tang & McKellar, JCP 117, 8308 (2002); 3 Song, Xu, Roy & Jäger, JCP 121, 12308 (2004).

3. 3 Nuclear Spin States N 2 O-pH 2 & -oD 2 are expected to exhibit similar behaviors as N 2 O- 4 He. J. Tang & A. R. W. McKellar, JCP, 117, 8308 (2002). pH2pH2 oD2oD2 oH2oH2 pD2pD2 I total = 0 I total = 0,2 I total = 1 j H = 0,2... j H = 0,2… j H = 1,3...

4. 4 Microwave Fourier Transform Spectrometer  Sample cell is a Fabry-Perot microwave cavity.  Pulsed excitation-spontaneous emission technique.  Microwave frequency range from 4 to 26 GHz.  Sample Composition: 0.25% N 2 O, 5% H 2 in He at 7 atm.

5. 5 Observed Rotational Transitions Two a-type and two b-type transitions for 14 N 14 NO-pD 2 and 14 N 15 NO-pD 2. One a-type and two b-type transitions for 15 N 14 NO-pD 2 and 15 N 15 NO-pD 2. One a-type transition for 14 N 14 NO-oH 2. Nuclear quadrupolar hyperfine structures due to 14 N ( I = 1) and pD 2 ( I total = 1) nuclei. J. Tang & A. R. W. McKellar, JCP, 117, 8308 (2002).

6. 6 Energy Level Diagram 1 11 0 00 1 01 1 10 Energy JKaKcJKaKc

7. 7 J K a K c = 1 01 -0 00 Transition of 14 N 14 NO-pD 2 Frequency (MHz) 1,2,3 - 1,2,3 2,3,3 - 1,2,2 1,0,1 - 1,1,2 F 1 ’,F 2 ’,F’- F 1 ”,F 2 ”,F” 18253.5 18254.918254.718254.5 18254.318254.1 18253.9 18253.7 2,1,2 - 1,1,2 2,3,4 - 1,2,3 1,1,2 - 1,0,1 2,2,2 - 1,1,1 2,2,3 - 1,1,2 1,1,1 - 1,0,1 1,2,3 - 1,2,3

8. 8 J K a K c = 1 11 -0 00 Transition of 14 N 14 NO-pD 2 Frequency (MHz) F 1 ’,F 2 ’,F’- F 1 ”,F 2 ”,F” 1,2,3 - 1,2,3 2,2,3 - 1,1,2 0,1,2 - 1,2,3 2,3,3 - 1,2,2 2,3,4 - 1,2,3 20302.4 20302.620302.8 20303.020303.220303.4 20303.6

9. 9 14 N 14 NO-pD 2 Constants *J. Tang & A. R. W. McKellar, JCP, 117, 8308 (2002). ConstantsValues (MHz)ConstantsValues (MHz) A 13915.5268(5)  aa ( 14 N-outer) -0.659(2) B 11863.6408(6)  bb ( 14 N-outer) 0.299(6) C 6391.0653(4)  cc ( 14 N-outer) 0.360(6) JJ 0.153*  aa ( 14 N-inner) -0.277(3)  JK 2.64*  bb ( 14 N-inner) 0.08(1) KK 0.024*  cc ( 14 N-inner) 0.192(1) JJ -0.002*  aa (D 2 ) -0.128(5) KK 1.200*  bb (D 2 ) -0.107(9)  (kHz) 1.7  cc (D 2 ) 0.235(9)

10. 10 J K a K c = 1 01 -0 00 Transition of 14 N 15 NO-pD 2 Frequency (MHz) 1,0 - 1,1 1,2 - 1,1 2,2 - 1,2 2,3 - 1,2 0,1 - 1,2 F 1 ’,F’- F 1 ”,F” 1,1 - 1,0 2,1 - 1,2 18243.0 18243.618243.818244.018243.4 18243.2

11. 11 J K a K c = 1 11 -0 00 Transition of 14 N 15 NO-pD 2 Frequency (MHz) 0,1 - 1,1 2,3 - 1,2 1,2 - 1,2 F 1 ’,F’- F 1 ”,F” 20280.0 20280.2 20280.420280.620280.8

12. 12 14 N 15 NO-pD 2 Constants ConstantsValues (MHz)ConstantsValues (MHz) A 13898.213(6)  aa ( 14 N-outer) -0.677(2) B 11858.4397(8)  bb ( 14 N-outer) 0.305(2) C 6385.7080(7)  cc ( 14 N-outer) 0.371(4) JJ 0.153*  aa (D 2 ) -0.09933(1)  JK 2.64*  bb (D 2 ) -0.0109(6) KK 0.024*  cc (D 2 ) 0.1103(9) JJ -0.002* KK 1.200*  (kHz) 1.6 *J. Tang & A. R. W. McKellar, JCP, 117, 8308 (2002).

13. 13 J K a K c = 1 01 -0 00 Transition of 14 N 14 NO-oH 2 Frequency (MHz) 20008.0 20009.2 20009.020008.820008.6 20008.420008.2

14. 14 Ab initio Calculations Program: MOLPRO 2002.6 Method: CCSD(T) Basis Set: aug-cc-pVTZ Midbond functions: 3s 3p 2d 1f 1g  s,p = 0.9, 0.3, 0.1  d = 0.6, 0.2  f,g = 0.6, 0.2 Basis Set Superposition Error (BSSE) was eliminated by applying the Counterpoise correction.

15. 15 Spatial Configurations H 2 -axis along R H 2 -axis ┴ R & In-plane H 2 -axis ┴ R & Out-of-Plane R θ

16. 16 Potential Energy Surfaces H 2 -axis along R PE= -110.0 cm -1 R= 4.25 Å θ= 165° PE= -102.8 cm -1 R= 4.50 Å θ= 0° H 2 -axis ┴ R & In-plane PE= -232.9 cm -1 R= 3.00 Å θ= 90° PE= -45.9 cm -1 R= 4.25 Å θ= 180° H 2 -axis ┴ R & Out-of-plane PE= -151.6 cm -1 R= 3.00 Å θ= 90° PE= -45.8 cm -1 R= 4.25 Å θ= 180° R (Å) -110 -100 -80 -60 -20 -40 0 -220 -200 -180 -100 -80 -140 -40 -20 0 -140 -120-100 -80 -60 -40 -20 0 Energies in cm -1

17. 17 Comparison of ab initio & Experimental Data J K a K c ’-J K a K c ” Observed Transitions (MHz) H 2 -axis along R (MHz) H 2 -axis ┴ R & In-plane (MHz) H 2 -axis ┴ R & Out-of-Plane (MHz) 1 01 -0 00 18254.148113538.67021283.47518996.653 1 11 -0 00 20303.034424698.93834784.48029924.432 1 10 -1 01 7516.660823418.13817905.49117786.454 1 10 -1 11 5467.74677306.7004404.4866858.675

18. 18 Future Work Assign rotational spectra of 14 N 14 NO-oH 2. Observe rotational transitions of N 2 O-pH 2 and N 2 O-oD 2. Create potential energy hybrid surface to predict bound state energies for the N 2 O-H 2 complexes. Measure higher order clusters for all N 2 O-H 2 isotopomers.

19. 19 Acknowledgments Qing Wen Jäger and Xu Groups And YOU!!!