1. Isomer Selection in NO 2 ˉ · H 2 O · Ar Rachael Relph Rob Roscioli, Ben Elliott, Joe Bopp, Tim Guasco, George Gardenier Mark Johnson Johnson Lab Yale University Presented at 63 rd International Symposium on Molecular Spectroscopy The Ohio State University

2. This project was made possible by:

3. Predissociation Yield 100014001800280032003600 Photon Energy, cm -1 The NO 2 ‾ · H 2 O System NO 2 ˉ · H 2 O · Ar + h → NO 2 ˉ · H 2 O + Ar

4. Predissociation Yield Photon Energy, cm -1 OH Stretching Region 280030003200340036003800 Cl ˉ · H 2 O NO 2 ˉ · H 2 O IHB free

5. MS-IR-MS-IR-MS Signal Time of Flight,  s Argon-solvated Isomer 1 Argon-solvated Isomer 2 Isomer 2 fragment induced by pump laser Isomer 2 fragment induced by probe laser h pump (P1) (scanned) h probe (P2) (fixed) population Reflectron 1 (R1) Reflectron 2 (R2) Coaxial TOF (PA) population ±1.5 keV probe fragment pump fragment probe fragment pump fragment

6. MS-IR-MS-IR-MS Signal Time of Flight,  s Argon-solvated Isomer 1 Argon-solvated Isomer 2 Isomer 2 fragment induced by pump laser Isomer 2 fragment induced by probe laser h pump (P1) (scanned) h probe (P2) (fixed) population Reflectron 1 (R1) Reflectron 2 (R2) Coaxial TOF (PA) population ±1.5 keV

7. 280030003200340036003800 Ion Dip Signal Predissociation Yield Photon Energy, cm -1 Ion Dip Signal A B Signal Time of Flight,  s Argon-solvated Isomer 1 Argon-solvated Isomer 2 Isomer 2 fragment induced by pump laser Isomer 2 fragment induced by probe laser h pump (P1) (scanned) h probe (P2) (fixed) population Reflectron 1 (R1) Reflectron 2 (R2) Coaxial TOF (PA) population ±1.5 keV Motions of the Water Molecule

8. 280030003200340036003800 Ion Dip Signal Predissociation Yield Photon Energy, cm -1 Ion Dip Signal A B Motions of the Water Molecule

10. Solvation Effects on NO 2 ‾ 100011001200130014001500 Photon Energy, cm -1 Time of Flight,  s pump B pump A pump B pump A probe fragment modulation probe fragment modulation Predissociation Yield NO str (back) 2

11. Solvation Effects on NO 2 ‾ 280030003200340036003800 Predissociation Yield Photon Energy, cm -1 A B 100011001200130014001500 Photon Energy, cm -1 Time of Flight,  s pump B pump A pump B pump A probe fragment modulation probe fragment modulation Predissociation Yield

12. 100014001800280032003600 Predissociation Yield Photon Energy, cm -1

13. Conclusions Successful application to a system with non- trivial spectral overlap of isomers Demonstration of single point averaging approach to extend spectral range Elucidation of solute response to different hydration motifs Good prospects for providing secure assignments in many unpublished examples of complex hydrated ion spectra

16. 100014001800280032003600 Calculated Intensity Predissociation Yield Photon Energy, cm -1 The NO 2 ‾ · H 2 O System NO 2 ˉ · H 2 O · Ar + h → NO 2 ˉ · H 2 O + Ar