1. Time Resolved Infrared Emission from Vibrational Excited Acetylene Following Super Energy Transfer Collisions with Hot Hydrogen Jonathan M. Smith Jianqiang Ma *, Michael J. Wilhelm, Matthew Nikow, and Hai-Lung Dai 68th International Symposium on Molecular Spectroscopy * University of Pennsylvannia

2. Observation: Time resolved IR Emission Translationally hot hydrogen o Abundant in photolytic systems (atmosphere) and combustion Relevant ambient targets o HCCH o DCCD: test model o SO 2 Infrared emission o Particularly sensitive to energized species Harmonic scaling of intensity Anharmonic shift Intensity primarily through IR harmonic transition dipole Time resolved o Capture emission of nascent or nearly nascent energized species (10 nsec+ ) o Dynamics Hartland, G.V., Xie, W., Dai, H.-L., Simon, A., Anderson, M.J., Rev. Sci. Instr., 63, 3261 (1992).

3. Super Energy Transfer Experimental Observation: o IR emission from Highly vibrationally excited species following interaction with hot hydrogen atom o Nearly 70% of H translational energy appears in internal energy in HCCH and SO 2 o Significant portion of encounters are “Super” Model: o Collisions sample deep minima on potential surface o Transient chemical complexes facilitate redistribution of energy Justification: o Strong collision assumption o Earlier observations: Chemical complexes facilitating inelastic collisions, “Tug of War” o Theory: Bowman group

4. H + XY( , J)  XY(  ’, J’) + HEnergy transfer (T-V) H + XY( , J)  HX(  ', J’) + Y(  ”, J”)Metathesis H + XY( , J)  HXY(  ’, J’)Combination + ++ ‡ [ ] ‡ + ++ * Generation of Translationally Hot hydrogen From: Wight, C. A.; Leone, S. R., "Vibrational state distributions and absolute excitation efficiencies for T-V transfer collisions of NO and CO with H atoms produced by excimer laser photolysis". J. Chem. Phys. 1983, 79 (10), 4823- 4829. E c.m. H+CO (mass =28) vs. HCCH (mass=26)

5. Energetics: H+HCCH

6. H * + HCCH H 2 S Photolysis 193 nm: σ=2.3 x 10 -18 cm 2 /molecule H E T =53 kcal/mole 50 mTorr HCCH 2 Torr Ar

7. H * + HCCH H 2 S Photolysis 193 nm: σ=2.3 x 10 -18 cm 2 /molecule H E T =53 kcal/mole 50 mTorr HCCH 2 Torr Ar

8. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605… Fundamental emission

9. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605… 7,000 cm -1 emission

10. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605… 9,000 cm -1 emission

11. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605… 13,000 cm -1 emission

12. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605… Observed experimental emission

13. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605…

14. HCCH emission simulation: Energy “yardstick” Excellent accurate spectroscopic effective Hamiltonian: Robert, S.; Herman, M.; Fayt, A.; Campargue, A.; Kassi, S.; Liu, A.; Wang, L.; Di Lonardo, G.; Fusina, L., "Acetylene, 12 C 2 H 2 : new CRDS data and global vibration- rotation analysis up to 8600 cm -1 ". Mol. Phys. 2008, 106 (21), 2581 - 2605…

15. H+HCCH H 2 S Photolysis 193 nm: σ=2.3 x 10 -18 cm 2 /molecule H E T =53 kcal/mole 50 mTorr HCCH 2 Torr Ar

16. Energy distribution and evolution: HCCH * 193nm photolysis of H 2 S in C 2 H 2 and Ar

17. Proposed Model Substantial highly excited HCCH * No vinyl emission observed Short-lived H+DCCD?

18. H+DCCD H 2 S Photolysis 193 nm: σ=2.3 x 10 -18 cm 2 /molecule H E T =53 kcal/mole 50 mTorr DCCD 2 Torr Ar

19. Proposed Model Substantial highly excited HCCH * No vinyl emission observed Short-lived H+DCCD yields [DCCH * ]/[DCCD * ]= ~ 2:1

20. Further support… HBr @ 209.4 nm: 39.6 kcal/mole 62% T-V QCT snapshot

21. Bowman Group: H+HCCH PES global fit of PES 50 000 energies at RCCSD(T)/aug-cc-pVTZ Detailed QCT study Han, Y.-C.; Sharma, A. R.; Bowman, J. M., "Quasiclassical trajectory study of fast H-atom collisions with acetylene". J. Chem. Phys. 2012, 136 (21), 214313.

22. Mechanistic insights from QCT QCT Experiment Find ~10% Super Energy Transfer Mechanistic insights 1.6-1.8 Angtrom 2 cross-section

23. General? H+SO 2 H*+SO 2 E (kcal/mol ) H+SO 2 OH+S O 0 -21.9 -44.2 9.2 27.3 29.2 19.5 59.0 See: Varandas et al., PCCP, 2005, 7, 2305

24. SO 2 IR emission o HBr as fast H atom precusor: 59kcal/mole translational energy with 193nm HBr + 193nm  H (59kcal/mole) + Br*/Br Emitting species in the 1000-1500cm -1 region H(fast) + SO 2  OH + SO* H(fast) + SO 2  H + SO 2 ‡ SO 2 + 193nm  SO* + O SO 2 ‡ ( ν 3 ) SO*/SO 2 ‡ ( ν 1 )

25. Energy distribution and evolution

26. H + SO 2  SO 2 ‡ Conclusion: SO 2 Energy transfer cross section σ: 0.9 ± 0.1 Å 2 Hard sphere cross section of H+SO 2 : 20 Å 2 H* + SO 2  HOSO/HSO 2  OH + SO The lifetime of HOSO/HSO 2 intermediates is reported to be as long as picoseconds

27. Acknowledgements Support Temple Hai-Lung Dai Matt Nikow, Ph.D. [Agilent] Jianqiang Ma, Ph.D. [Univ. Penn.] Michael Wilhelm, Ph.D. Ben Datko (ug, ‘13) Nader Anz (ug, ‘12) Mark Fennimore (ug. ‘11) Emory University Joel Bowman Amit Sharma [Argonne] Yong-Chang Halian [Dalian Univ.] DE-FG 02-86ER134584 DE-FG 02-97ER14782 (JMB) NSF-MRI 1039925: MU3C Temple University