1. Formation of Astrobiologically Important Molecules in Extraterrestrial Environments Ralf I. Kaiser Department of Chemistry University of Hawai’i Honolulu, HI 96822 kaiser@gold.chem.hawaii.edu http://www.chem.hawaii.edu/Bil301/welcome.html

2. Orion Constellation Orion Nebula

3. es = 10 - molecular clouds and cores circumstellar envelopes Interstellar Medium T = 10 – 4000 K  = 10 2 – 10 9 cm -3 T = 10 K  = 10 -11 cm -3

5. Amino Acid

6. Characteristics of a Chemical Reaction 1. exoergic vs. endoergic 2. no entrance barrier vs. barrier 3. binary vs. ternary reactions

7. The 70es – Bimolecular Ion-Molecule Reactions k = 10 -9 cm 3 s -1 (Herbst et. al) O O + + e - O + + H 2 OH + + H OH + + H 2 OH 2 + + H OH 2 + + H 2 OH 3 + + H OH 3 + + e - H 2 O + H simple hydrides in cold molecular clouds (CH 4, NH 3, H 2 O)

8. The 80es – Problems with Ion-Molecule Reactions

10. The 90es – Bimolecular Neutral-Neutral Reactions CN(X 2  + ) + C n H m C n H (m-1) CN + H C 2 H(X 2  + ) + C n H m C n H (m-1) C 2 H + H C( 3 P j ) + C n H m C (n+1) H (m-1) + H k = 10 -10 cm 3 s -1 (Kaiser et al.; Smith et al.) C 2 (X 1  g + ) + C n H m C (n+2) H (m-1) + H

11. The 90es – Bimolecular Neutral-Neutral Reactions Titan IRC+10216

12. es = 10 - molecular clouds and cores circumstellar envelopes Interstellar Medium T = 10 – 4000 K  = 10 2 – 10 9 cm -3 T = 10 K  = 10 -11 cm -3

13. UV photons cosmic ray particles Cold Molecular Cloud B68

14. carbon dioxide carbon monoxide water methaneammonia methanol

15. The late 90es – Grain-Surface Reactions H + H H 2

16. carbon dioxidecarbon monoxide water methane ammonia methanol

17. The 00es - Galactic Cosmic Ray Processing 10 MeV 9 MeV 1.ionization 2. electronic excitation 3. vibrational excitation 4. electron attachment cleavage of chemical bonds ‘electronic’ interaction

18. The 00es - Galactic Cosmic Ray Processing 1. Energy Conservation 10 eV transfer – 4.5 eV bond energy = 5.5 eV maximum kinetic energy 2. Angular Momentum Conservation H atom (5.15 eV) versus CH 3 radical (0.35 eV) kinetic energy vibrational energy

19. Non-Equilibrium Chemistry 1. exoergic vs. endoergic 2. no entrance barrier vs. barrier 3. binary vs. ternary reactions A* + BC

20. C 2 H 4 O Isomers acetaldehyde ethylene oxidevinyl alcohol H 2 O, CO, CO 2, NH 3, CH 4, CH 3 OH CO/CH 4 CO 2 /C 2 H 4 H 2 O/C 2 H 2

21. C 2 H 4 O Isomers acetaldehyde ethylene oxidevinyl alcohol

22. Surface Scattering Machine T = 10 – 350 K p = 8  10 -11 torr LET (5 keV e - ) = 3 – 5 keV  m -1 = LET (10 MeV H + ) 30 min laboratory = 10 6 years in cold molecular cloud

25. 1.electron source 2. cation source (positively charged particles) Sources 3. pyrolytic radical source 4. tunable photon source

26. CO/CH 4 Ice before Irradiation at 10 K

27. CO/CH 4 Ice after Irradiation at 10 K 612 cm -1 2 (CH 3 out of plane)

28. CO/CH 4 Ice after Irradiation at 10 K 1853 cm -1 3 (HCO; CO stretch)

29. CO/CH 4 Ice after Irradiation at 10 K 1725 cm -1 4 (CH 3 CHO; CO stretch)

30. QMS: CO/CH 4 during Irradiation H + H H 2

31. CO/CH 4 Ices after Irradiation at 10 K [CH 4 -CO] [CH 3 …HCO] CH 3 CHO

32. Kinetics (pseudo) 1 st order kinetics electron induced decomposition [CH 4 -CO] [CH 3 …HCO] CH 3 CHO

33. Kinetics [CH 4 -CO] [CH 3 …HCO] CH 3 CHO k1k1 k2k2 a = 2.32 (  0.42)  10 15 cm -2 k 1 <<k 2 = 1.13 (  0.29)  10 -11 s -1 a = 2.32 (  0.42)  10 15 cm -2 k 1 <<k 2 = 1.13 (  0.29)  10 -11 s -1

34. CH 4 (X 1 A 1 ) CH 3 (X 2 A 2 ’’ ) +H( 2 S 1/2 ) CO (X 1   ) +H( 2 S 1/2 ) HCO (X 2 A ’ ) a = 3.87 (  0.18)  10 15 cm -2 k 3 = 4.4 (  0.37)  10 -11 s -1 a = 3.87 (  0.18)  10 15 cm -2 k 3 = 4.4 (  0.37)  10 -11 s -1 a = 3.39 (  0.15)  10 15 cm -2 k 4 = 5.49 (  0.73)  10 -11 s -1 a = 3.39 (  0.15)  10 15 cm -2 k 4 = 5.49 (  0.73)  10 -11 s -1 k3k3 k3k3 k4k4 k4k4 Kinetics [CH 4 -CO] [CH 3 …HCO] CH 3 CHO

35. Electronic Structure Calculations Osamura et al. 2004

36. C 2 H 4 O Isomers acetaldehyde ethylene oxidevinyl alcohol H 2 O, CO, CO 2, NH 3, CH 4, CH 3 OH CO/CH 4 CO 2 /C 2 H 4 H 2 O/C 2 H 2

37. CO 2 /C 2 H 4 Ices after Irradiation at 10 K 2139 cm -1 1 (CO; stretch)

38. CO 2 /C 2 H 4 Ices after Irradiation at 10 K 1723 cm -1 4 (CH 3 CHO; CO stretch)

39. CO 2 /C 2 H 4 Ices after Irradiation at 10 K 868 cm -1 12 (c-C 2 H 4 O; ring)

40. Kinetics (pseudo) 1 st order kinetics electron induced decomposition [C 2 H 4 -CO 2 ] [C 2 H 4 …O…CO] [C 2 H 4 O+CO]

41. C 2 H 4 + O CH 3 CHO a = 2.10 (  0.09)  10 15 cm -2 k 1 = 5.22 (  0.37)  10 -12 s -1 a = 2.10 (  0.09)  10 15 cm -2 k 1 = 5.22 (  0.37)  10 -12 s -1 a = 1.77 (  0.05)  10 15 cm -2 k 2 = 6.29 (  0.34)  10 -12 s -1 a = 1.77 (  0.05)  10 15 cm -2 k 2 = 6.29 (  0.34)  10 -12 s -1 k1k1 k1k1 Kinetics C 2 H 4 + O c-C 2 H 4 O k2k2 k2k2

42. Mechanism

43. ‘cone of acceptance’ favors attack of  bond (formation of acetaldehyde and ethylene oxide)

44. Mechanisms [CH 4 -CO] [CH 3 …HCO] CH 3 CHO a = 2.32 (  0.42)  10 15 cm -2 k = 1.13 (  0.29)  10 -11 s -1 a = 2.32 (  0.42)  10 15 cm -2 k = 1.13 (  0.29)  10 -11 s -1 [C 2 H 4 -CO 2 ] [C 2 H 4 …O…CO] [C 2 H 4 O+CO] a = 2.10 (  0.09)  10 15 cm -2 k = 5.22 (  0.37)  10 -12 s -1 a = 2.10 (  0.09)  10 15 cm -2 k = 5.22 (  0.37)  10 -12 s -1 a = 1.77 (  0.05)  10 15 cm -2 k = 6.29 (  0.34)  10 -12 s -1 a = 1.77 (  0.05)  10 15 cm -2 k = 6.29 (  0.34)  10 -12 s -1 CH 3 CHOc-C 2 H 4 O kinetics versus dynamics

45. C 2 H 4 O Isomers acetaldehyde ethylene oxidevinyl alcohol H 2 O, CO, CO 2, NH 3, CH 4, CH 3 OH CO/CH 4 CO 2 /C 2 H 4 H 2 O/C 2 H 2 synchrotron irradiations are crucial to discriminate between O( 3 P) and O( 1 D)

46. es = 10 - molecular clouds and cores circumstellar envelopes Interstellar Medium T = 10 – 4000 K  = 10 2 – 10 9 cm -3 T = 10 K  = 10 -11 cm -3

47. Crossed Molecular Beams Machine

48. Acknowledgements Chris Bennett (UH, USA) Corey Jamieson (UH, USA) Prof. Nigel Mason (OU, UK) Prof. Yoshihiro Osamura (Tokyo, Japan)