Max Planck Institute for the Structure and Dynamics of Matter Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry Benjamin E. Arenas1 Amanda L. Steber1,2 Sébastien Gruet1,2 Melanie Schnell1,2 1Max Planck Institute for Structure and Dynamics of Matter, Hamburg, Germany 2The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany Max Planck Institute for the Structure and Dynamics of Matter

Introduction To increase the output of laboratory spectra for: Astrochemistry Organic Molecules Interstellar Ice Grains Analysis of Chiral Compounds Intermolecular Interactions Controlling Cold Molecules To increase the output of laboratory spectra for: Detecting new molecules; Exploring the importance of excited states and isotopologues; Chemical reactions. See also: Amanda L. Steber, “The Study of Acenaphthene and its Complexation with Water”, [TH12] Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

75 –110 GHz Spectrometer Segmented chirped-pulse Fourier transform millimeter-wave rotational spectrometer Pulses AWG writes pulses Amplified and up-converted Chamber mmw transmitted into chamber Interaction with molecules Detection FID collected, down-converted, amplified and digitised Fourier transform Local oscillator frequency for down-conversion of FID 1 J.L. Neill et al., Opt. Express 21 (2013) 19743-19749 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

75 –110 GHz Spectrometer Still to come… Molecular interaction chamber Receiver Sample inlet mmw transmitter Still to come… New molecular interaction chamber Electrical discharge Laser ablation Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

1,2-Propanediol 1,2-Ethanediol 1,2-Propanediol AKA ethylene glycol Detected in the ISM in 20022 1,2-Propanediol 6.5 – 25.0 GHz3 7 conformers 38 – 70, 200 – 230, 297 – 400 GHz4 3 conformers 2 J. M. Hollis et al., ApJ 571 (2002) L59-L62 3 F. J. Lovas et al., J. Mol. Spectrosc. 257 (2009) 82-93 4 J.-B. Bossa et al., A&A 570 (2014) A12 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

The Conformers of 1,2-Propanediol 3 F. J. Lovas et al., J. Mol. Spectrosc. 257 (2009) 82-93 Conformer Energy (cm-1) 1 2 74 3 115 4 212 5 230 6 349 7 375 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

1,2-Propanediol – Spectrum Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

1,2-Propanediol – Spectrum Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

1,2-Propanediol – Structures Conformer 1 Conformer 2 Conformer 3 Conformer 4 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

1,2-Propanediol Comparison Conformer 1 Lovas et al., 2009 A (MHz) 8572.0578(14) 8572.0553(8) B (MHz) 3640.10483(54) 3640.1063(5) C (MHz) 2790.96687(52) 2790.9666(4) ΔJ (kHz) 0.73605(94) 0.738(7) ΔJK (kHz) 5.3417(33) 5.276(30) ΔK (kHz) 2.481(18) 2.53(10) δJ (kHz) 0.16222(31) 0.1631(16) δK (kHz) 3.171(10) 3.180(31) # of Lines 122 - MW rms (kHz) 25.304 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Vibrational States of 1,2-Propanediol Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Isopropyl Cyanide Studied in the mw and mmw regions 28 – 38 GHz5 3 vibrationally excited states 0 – 20, 37 – 69, 303 – 346, 589 – 600 GHz6 Detected in the ISM in 20147 First branched organic molecule Could point towards other branched organic molecules Possible amino acid precursor 5 J. R. Durig and Y. S. Li, J. Mol. Spectrosc. 21 (1974) 289-297 6 H. S. P. Müller et al., J. Mol. Spectrosc. 267 (2011) 100-107 7 A. Belloche et al., Science 345 (2014) 1584-1587 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Isopropyl Cyanide In collaboration with Dr. B. Michela Giuliano at the Centre for Astrochemical Studies at MPE Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Isopropyl Cyanide ν29 Ground state ν17 Müller et al., 2011 A (MHz) 7940.8746(16) 7940.877174 (31) B (MHz) 3968.08888(52) 3968.087775(27) C (MHz) 2901.05458(53) 2901.053223(22) DJ (kHz) 0.6127(12) 0.66102684(153) DJK (kHz) 12.1698(43) 12.17725 (42) DK (kHz) -5.231(27) -5.23242(61) d1 (kHz) -0.24393(11) -0.2440908(69) d2 (kHz) -0.189404(63) -0.1892889(76) HJK (Hz) 0.0347(16) 0.038267(140) h2 (Hz) 0.000931(72) 0.00088423(83) h3 (Hz) 0.000326(33) 0.00032239(140) # of Lines 173 - MW rms (kHz) 26.963 ν29 Ground state ν17 Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Conclusions and Outlook 75 – 110 GHz segmented chirped-pulse rotational spectrometer Organic molecules in the ISM 1,2-Propanediol Isopropyl cyanide Low frequency vibrations that are difficult to observe with IR spectroscopy Exploration of conformers, excited states and isotopologues New chamber Electrical discharge and laser ablation apparatus Chemical reactions and reaction mechanisms Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Acknowledgements Thank you! Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry

Max Planck Institute for the Structure and Dynamics of Matter Segmented Chirped-pulse Millimeter-wave Spectroscopy for Astrochemistry Benjamin E. Arenas1 Amanda L. Steber1,2 Sébastien Gruet1,2 Melanie Schnell1,2 1Max Planck Institute for Structure and Dynamics of Matter, Hamburg, Germany 2The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany Max Planck Institute for the Structure and Dynamics of Matter