70th International Symposium on the Molecular Spectroscopy June 22-26, 2015 The Laser Spectroscopy Facility Department of Chemistry and Biochemistry Mourad Rodjane, Terrance Codd, Ming-Wei Chen, Henry Tran, Dmitry Melnik, Terry A. Miller, John F. Stanton

The “important” electronic states of NO 3 T HE A-X E LECTRONIC S PECTRUM OF NO 3 : S OME T HEORETICAL R ESULTS AND I DEAS John F. Stanton and Christopher S. Simmons 66 th OSU International Symposium on Molecular Spectroscopy, TJ03, June 20-24,2011 X̃2A2′X̃2A2′ A ̃ 2 E a ′′ A ̃ 2 E b ′′ B̃2Ea′B̃2Ea′ B̃2Eb′B̃2Eb′ B̃2Eb′B̃2Eb′ B̃2Ea′B̃2Ea′ A ̃ 2 E a ′′ X̃2A2′X̃2A2′ A ̃ 2 E b ′′ W. Eisfeld & K. Morokuma, J. Chem. Phys., 2001, 114, 9430

The “important” electronic states of NO , 4 JT A true multistate, multimode system with rich spectra and plenty of unsolved problems! T HE A-X E LECTRONIC S PECTRUM OF NO 3 : S OME T HEORETICAL R ESULTS AND I DEAS John F. Stanton and Christopher S. Simmons 66 th OSU International Symposium on Molecular Spectroscopy, TJ03, June 20-24,2011 X̃2A2′X̃2A2′ A ̃ 2 E a ′′ A ̃ 2 E b ′′ B̃2Ea′B̃2Ea′ B̃2Eb′B̃2Eb′ B̃2Eb′B̃2Eb′ B̃2Ea′B̃2Ea′ A ̃ 2 E a ′′ X̃2A2′X̃2A2′ A ̃ 2 E b ′′ pJT

Previous Experimental Work on Hirota and colleagues reported observation of the and bands of the electronically forbidden transition b First broad range spectrum was taken by Deev et al. in an ambient CRDS experiment c Several bands were assigned in this work and evidence of strong JT coupling was reported Jacox and Thompson recorded FTIR spectra of the transition in a Ne matrix experiment d It significantly extended the spectral range and made several more assignments They reported evidence of weak JT coupling in 4 Most recently, Takematsu et al. have reported the observation of the vibronically forbidden origin of the transition and observed several hot bands e They refined the position of the origin band to cm -1 and reported a second peak roughly 8 cm -1 to the blue a. A. Weaver, D. W. Arnold, S. E. Bradforth, D. M. Neumark. J. Chem. Phys. 94, 1740 (1991) b. K. Kawaguchi, T. Ishiwata, E. Hirota, I. Tanaka. Chem. Phys. 231, 193 (1998). E. Hirota, T. Ishiwata, K. Kawaguchi, M. Fujitake, N. Ohashi, I. Tanaka. J. Chem. Phys. 107, 2829 (1997) c. A. Deev, J. Sommar, M. Okumura. J. Chem. Phys, 122, (2005). d. M. E. Jacox, W. E. Thompson. J. Phys. Chem. A, 114, (2010). e. K. Takematsu, N. C. Eddingsaas, D. J. Robichaud, M. Okumura, Chem. Phys. Lett., 555, (2013) f. T. Codd, M.-W. Chen, M. Roudjane, J. F. Stanton, T. A. Miller, J. Chem. Phys., 142, (2015). Observation of the photodetachment spectrum from NO 3 - to the states of NO 3 by Weaver, et al. a Jet-cooled vibronically resolved NO 3 spectra f

≈≈≈ (ground state) ≈ NO 3 Vibronic Structure and Transitions Vibronically allowed transitions:

Nd:YAG pulse laser Raman Cell PD InGaAs Detector Ring-down cavity with slit-jet discharge (absorption length ℓ = 5 cm) L = 67 cm Vacuum Pump ℓ R ~ – 1.3  m SRS (1 m, 18 atm H 2 ) 20 Hz, 8ns, 500 mJ MR-JC-CRDS Experimental Setup Sirah Dye Laser Filters 1 st or 2 nd Stokes 2-10 mJ,Δ ν~3 GHz Collimator 20 Hz, 8ns, 100 mJ 20 m Fiber Optic

a.u. Comparison of Observed and Simulated Line positions

a.u. Comparison of Observed and Simulated Line positions

Characteristics of the Potential Energy Surface from Vibronic Analysis Study Rotational Structure! E Bar =2295 cm -1 BF E JTSE =5736 cm -1 BF CAL E JTSE =2999 cm -1 CAL E Bar =1093 cm -1 CAL

U v=0 v=1 e e a2a2 a1a1 No JT JT 1 +JT 2 e a2a2 a1a1 e Strong JT 2 This results in localization in one of three minima, corresponding to a lower symmetry molecular structure. Degeneracy is ro-vibronic and rotational structure corresponds to an asymmetric top Near triple degeneracy Influence of JT Coupling on Rotational Structure D 3h C 2v

Matrix Elements in the Vibronic Eigenfunction Basis The energy difference, ΔE i, is due to Jahn-Teller effects is rovibronic coupling between different vibronic states H d is an oblate symmetric top (B, C) including centrifugal distortion(D JK ), spin-orbit (a ζ e d), and spin-rotation ( ii ) terms as necessary denotes the derivative coupling part (Watson term) of the Coriolis interaction in degenerate vibronic states Vibronic Hamiltonian,, for Nuclear Motion on the Electronic Potential Energy Surface, V

a.u. Comparison of Observed and Simulated Line positions

Ti:Sa ring cw laser Ti:Sa Amplifier (2 crystals) Nd:YAG pulsed laser Raman Cell PD InGaAs Detector Ring-down cavity with slit-jet discharge (absorption length ℓ = 5 cm) L = 67 cm Vacuum Pump nm,  ~ 1 MHz mJ  ~ MHz (FT limited) ℓ Nd:YVO 4 cw laser R ~ – 1.3  m SRS (1 m, 13 atm H 2, Δν~200 MHz ) 20 Hz, 8ns, 350 mJ HR-JC-CRDS Experimental Setup BBO Nd:YAG pulsed laser (seeded) 20 Hz, 8ns, 500 mJ DFM ( Δν~50 MHz ) 1-5 mj, <100MHz

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

a.u. Comparison of Observed and Simulated Line positions

Simulation of Lower rotational temperature. Lines are less dense and spectrum is well simulated. [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of [1] [1] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013).

Simulation of Split lines. Probably caused by perturbations from “dark”, high vibrational levels of X ̃ state

Comparison of Molecular Parameter for [2] [1] E. Hirota, T. Ishiwata, K. Kawaguchi, M. Fujitake, N. Ohashi, and I. Tanaka, J. Chem. Phys, 107, 2829 (1997). [2] Kentarou Kawaguchi, Ryuji. Fujimori, Jian Tang, Takashi Ishiwata. FTIR Spectroscopy of NO 3 : Perturbation Analysis of the ν 3 +ν 4 State, J. Phys. Chem. A, 117 (50), pp 13732–13742 (2013). [1] The value of the effective spin-orbit coupling between X and A states is ~70 cm -1 ~ ~ All Oblate Symmetric Tops with Zero Spin-orbit Coupling

Conclusions Over 20 Vibronic Bands in the Electronic Transition of NO 3 have been Observed and Used to Determine Jahn-Teller Distortion Parameters for a Model Vibronic Hamiltonian Thank You! The Structure of Several of These Bands from the Vibrationless Level of the Ground State to Vibronic Levels of the Lowest Excited State has been Rotationally Analyzed with an Oblate Symmetric Top Hamiltonian Yielding Rotational and Spin- rotational Constants. None of these Rotational Analyses Demonstrate Any Jahn-Teller Distortion Nor Any Spin-Orbit Interaction. The Rotational Structure (including electronic spin effects) has been Resolved for about Half the Vibronic Bands NO 3 is a True Multistate, Multimode System with Rich Spectra. However Despite Much Recent Progress There Remain Plenty of Unsolved Problems!

ACKNOWLEDGEMENTS Post-docs Graduate Students Research Scientist $$$$$$ Ming-Wei Chen – Post-doc UIUC Rabi Chhantyal Pun – Post-doc U. Bristol, UK Gabriel Just – Coherent Jinjun Liu – Faculty, U. Louisville Dmitry Melnik - LiCor Neal Kline – US Army Edgewood Chem & Bio Center Terrance Codd – QC Holding Co. Mourad Roudjane - OSU U. S. Department of Energy Meng Huang- OSU Henry Tran Undergraduate Student John Stanton, Professor, University of Texas at Austin