11 The THz spectrum of GlycolAldehyde M. Goubet, T.R. Huet, I. Haykal, L. Margulès PhLAM, CNRS – Université de Lille 1 O. Pirali, P. Roy AILES beamline, synchrotron SOLEIL OSU ISMS – June Laboratoire de Physique des Lasers, Atomes et Molécules Tél. +33 (0) | Fax. +33 (0) www-phlam.univ-lille1.fr

2 stable isomers of the chemical formula C 2 H 4 O 2 GlycolAldehyde (GA) detected in the ISM prebiotic molecule (simpliest sugar) Acetic Acid (AA) detected in the ISM various industrial apps (most abundant carboxylic acid): polymers, drugs, food ads, solvents MethylFormate (MF) detected in the ISM few industrial apps (harmful and flammable): insecticide, drugs, refrigerant The THz spectrum of GlycolAldehyde OSU ISMS – June

3 Astrophysical interest Regions of characteristic signals of COMs Support to space observation missions (Herschel, Alma, …) Inaccurate extrapolations from mm-waves Spectroscopic interest Large amplitude motions and intermolecular modes are in the FIR Low excitation energy = non-destructive probing  access to the dynamic, conformational and structural properties. Why from the mm-waves to FIR regions ? MF - 18 O 100 K The THz spectrum of GlycolAldehyde OSU ISMS – June

4 The GA spectrum: background No FIR spectrum of GA (dimeric powder in standard conditions) C-C torsion ( 1 ) ~ 200 cm -1 (very weak) C-C-O bend ( 2 ) ~ 300 cm -1 (weak) C-OH torsion ( 3 ) ~ 370 cm -1 (medium) + hot and combination bands M. L. Senent, J. Phys. Chem. A 108 (2004) 6286 Previous studies in the cm-, mm- and submm-waves regions: M. Rey et al., Chem. Phys. Lett. 430 (2006) 121. K.-M. Marstokk et al., J. Mol. Struct. 5 (1970) 205. R.A.H. Butler et al., ApJS 134 (2001) 319. S.L. Widicus-Weaver et al., ApJS 158 (2005) 188. P.B. Carroll et al., ApJ 723 (2010) 845.  global fit including all data The THz spectrum of GlycolAldehyde OSU ISMS – June

55 The GA spectrum: new data in the THz region The r Q branch (J~55, Ka=36) P = mbar, T = 294 K, 780 – 950 GHz region. The Lille spectrometer See talks: FA07 – FA08 – FA09 The THz spectrum of GlycolAldehyde OSU ISMS – June

66 Data in the GHz range from Lille/Oslo/Columbus/JPL fitted at the experimental accuracy: ParameterThis WorkCaroll et alParameterThis WorkCaroll et al A (24) (134)  J x (16)-7.710(170) B (86) (51)  JK x (18)170.86(168) C (91) (50)  KJ x (46)-825.6(57)  J x (58) (47)  K x (77)1060.9(65)  JK x (33) (219)  J x (21) (253)  K x (68) (36)  JK x (91)-25.42(105)  J x (12) (112)  K x (12)309.6(174)  K x (31)8.8676(45)L J x (13)0.0776(222) J max 8063L JJK x (26)0.211(203) K max 3732L JK x (74)-3.90(65) N of Lines L KKJ x (18)26.65(154) Fit rms L K x (31)-21.82(252) Ground state parameters (in MHz) The THz spectrum of GlycolAldehyde OSU ISMS – June

77 Data in the GHz range from Lille/Oslo/Columbus/JPL fitted at the experimental accuracy: Excited states results This workpreviousThis workpreviousThis workprevious J max K max N of Lines Fit RMS (MHz) The THz spectrum of GlycolAldehyde OSU ISMS – June

88 The GA spectrum: new data in the FIR (Soleil SR + IFS125HR + long pass Ailes beamline: High brightness in the FIR: less scans needed White type multipass cell: absorption length = 150 m  High sensitivity for low vapor pressure samples. The THz spectrum of GlycolAldehyde OSU ISMS – June

99 The GA spectrum: new data in the FIR The THz spectrum of GlycolAldehyde OSU ISMS – June (1←0) 3 (2←1) 2 (1←0) 1 (1←0) 1 (2←1) 1 (3←2) 1-3 (?←?) HR (10 -3 cm -1 ) spectrum of GA (< AILES – long pass (150 m) cell

10 The GA spectrum: new data in the FIR Wavenumber / cm -1 The THz spectrum of GlycolAldehyde OSU ISMS – June

11 1 (1 ← 0) 2 (1 ← 0) 3 (1 ← 0) Band origin207.6 (199.3) (294.0) (368.7) Jmax50 80 Kmax No of Lines Fit RMS Accuracy Global fit: vibrational results (in cm -1 ) Data in the cm -1 range fitted at the experimental accuracy: In parenthesis: ab initio values from M. L. Senent, JPCA 108 (2004) 6286 The THz spectrum of GlycolAldehyde OSU ISMS – June

12 The GA spectrum: perspectives Analysis of the hot and combination bands x 3-3, x 1-1 and x 1-3 anharmonicity constants Intramolecular H-bond properties (C-OH torsion not perturbed and high ~ 350 cm -1 / e.g. Ethanol ~ 200 cm -1 ) The THz spectrum of GlycolAldehyde OSU ISMS – June Experimental and a- and b- type sticks spectrum of 2 3 (2←1)

13 Acknowledgments Financial funding: ANR « TopModel » (ANR-08-BLAN-0054) ; Programme PCMI and many thanks for your attention T. Huet P. RoyO. Pirali L. Margulès I. Haykal 13 Laboratoire de Physique des Lasers, Atomes et Molécules Tél. +33 (0) | Fax. +33 (0) www-phlam.univ-lille1.fr