THE MILLIMETER-WAVE SPECTRUM OF VINYL ACETATE Grupo de Espectroscopía Molecular, Lab. de Espectroscopia y Bioespectroscopia Edificio Quifima, Unidad Asociada CSIC, Universidad de Valladolid, Valladolid, Spain Departamento de Astrofísica, Centro de Astrobiología, CAB, CSIC-INTA, Madrid, Spain CNRS et Universités Paris Est et Paris Diderot, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Creteil, France THE MILLIMETER-WAVE SPECTRUM OF VINYL ACETATE Lucie Kolesniková, Isabel Peña, José L. Alonso, José Cernicharo, Belén Tercero, Isabelle Kleiner International Symposium on Molecular Spectroscopy, June 16  20, 2014 Champaign-Urbana, Illinois, USA

Introduction and motivation Methyl acetate (CH3COOCH3) Gauche-ethyl formate (g-CH3CH2OCOH) detected in ORION KLa detected in Sgr B2b a Tercero B. , Kleiner I., Cernicharo J. , Nguyen H. V. L., Lopez A. , and Muñoz Caro G. M., 2013, ApJ. 770, L13. b Belloche, A., Garrod, R. T., Műller, H. S. P., et al. 2009, A&A, 499, 215.

Introduction and motivation Methyl acetate (CH3COOCH3) Gauche-ethyl formate (g-CH3CH2OCOH) Methyl acetate (CH3COOCH3) Gauche-ethyl formate (g-CH3CH2OCOH) Vinyl acetate (CH3COOCHCH2) – one of the simplest unsaturated carboxylic ester Previous data up to 77 GHzc → new data → search in Orion KL detected in ORION KLa detected in Sgr B2b acetate containing molecules are potential candidates a Tercero B. , Kleiner I., Cernicharo J. , Nguyen H. V. L., Lopez A. , and Muñoz Caro G. M., 2013, ApJ. 770, L13. b Belloche, A., Garrod, R. T., Műller, H. S. P., et al. 2009, A&A, 499, 215. c Velino B., Maris A., Melandri S., Caminati W. J Mol. Spectrosc. 256 (2009) 228 – 231.

Vinyl acetate molecule Predicted conformersb DE = 0 cm1 DE = 1060 cm1 DE = 2313 cm1 b Velino B., Maris A., Melandri S., Caminati W. J Mol. Spectrosc. 256 (2009) 228 – 231.

Vinyl acetate molecule MP2/6-311++g(d,p): ma = 0.04 D mb = 1.62 D mc = 0.09 D The most stable conformer Previous data (61 – 77 GHz)b  predictions (BELGI-Cs) Velino et. al.b: V3 = 155.111 (93) cm1 A-E splitting b Velino B., Maris A., Melandri S., Caminati W. J Mol. Spectrosc. 256 (2009) 228 – 231.

CP-FTMW spectra: experiment CP-FTMW spectrometer (6 – 18 GHz)c Supersonic Expansion 2 nozzels Ne carrier gas (2 bar) Broadband FT-MW spectrometer c S. Mata I. Peña, C. Cabezas, J. C. López and J. L. Alonso. J. Mol. Spectrosc. 280 (2012) 91–96

CP-FTMW spectra: analysis 6 – 18 GHz

CP-FTMW spectra: analysis 6 – 18 GHz 2 1 1  2 0 2 1 1 1  0 0 0 2 1 2  1 0 1 1 1 0  1 0 1 A E E A E A A E 3 1 2  3 0 3 A E

CP-FTMW spectra: analysis 6 – 18 GHz 2 1 1  2 0 2 1 1 1  0 0 0 2 1 2  1 0 1 1 1 0  1 0 1 A E E A E A A E 3 1 2  3 0 3 A E

CP-FTMW spectra: analysis 6 – 18 GHz 2 1 1  2 0 2 1 1 1  0 0 0 2 1 2  1 0 1 1 1 0  1 0 1 A E E A E A A E 3 1 2  3 0 3 A E Parent species A-lines: 1 1 0  1 0 1 13C3 13C2 13C1 13C4 18O1 18O2

CP-FTMW spectra: analysis 6 – 18 GHz 2 1 1  2 0 2 1 1 1  0 0 0 2 1 2  1 0 1 1 1 0  1 0 1 A E E A E A A E 3 1 2  3 0 3 A E assignments of the transitions of the parent species and isotopologues search for the second conformer Parent species A-lines: 1 1 0  1 0 1 13C3 13C2 13C1 13C4 18O1 18O2

CP-FTMW spectra: results A-species rotational constants (MHz) Parent species 13C1 13C2 13C3 13C4 18O1 18O2 A 9436.2220 (86) 9424.5281 (92) 9421.2015 (98) 9435.194 (12) 9296.1454 (58) 9344.686 (11) 8895.465 (23) B 2243.1532 (16) 2178.0120 (46) 2223.9524 (21) 2234.434 (17) 2202.5830 (27) 2241.8028 (91) 2220.264 (24) C 1832.4004 (17) 1788.2639 (27) 1819.0190 (29) 1826.6583 (69) 1800.0171 (16) 1828.0230 (48) 1796.027 (12) Atom Substitution coordinates (Å) (assumption of the symmetry plane) |a| |b| C1 2.60635 (58) 0.2641 (57) C2 1.3989 (11) 0.2953 (51) C3 0.9314 (17) 0.080 (19) C4 2.04148 (74) 0.9132 (16) O1 0.2625 (57) 0.5179 (29) O2 1.0793 (14) 1.2982 (12)

MMW spectra: experiment MMW and sub-MMW spectrometer (50 – 1000 GHz) 129 – 360 GHz room temperature 20 mbar

MMW spectra: experiment MMW and sub-MMW spectrometer (50 – 1000 GHz) 129 – 360 GHz room temperature 20 mbar Synthesizer Sample cells Lock-in amplifier AM chains Lens

MMW spectra: experiment MMW and sub-MMW spectrometer (50 – 1000 GHz) Roof-top mirror Detector Synthesizer Sample cells Lock-in amplifier AM chains Lens

MMW spectra: analysis MMW spectrum E A E A E A E A E A A

MMW spectra: analysis AABS package:http://info.ifpan.edu.pl/~kisiel/aabs/aabs.htm ncent (MHz) Dn (MHz)

MMW spectra: analysis E A E A E A E A Ka’’ = 3, 4 Ka’’ = 2, 3 ncent (MHz) E A E A E A E A Dn (MHz)

MMW spectra: analysis J’’ = 95, Ka’’ = 16 J’’ = 95, Ka’’ = 10 ncent (MHz) E A E A E A E A CP-FTMW + MMW spectra > 1400 transitions (A-species) J’’ = 95, Ka’’ = 16 > 900 transitions (E-species) J’’ = 95, Ka’’ = 10 BELGI-Cs code (rho-axis method) Dn (MHz)

CP-FTMW + MMW spectra: results Operatora Constant Unit Value Pa2 A cm-1 0.3026567 (31) Pb2 B 0.0848837 (11) Pc2 C 0.061139775 (45) {Pa,Pb} Dab -0.047932 (45) {Pa,Pc}(sin3) Dac 0.000639 (13) -P4 DJ x 10-8 0.52753 (48) -Pa4 DK x 10-6 0.31561 (46) -2P2(Pb2-Pc2) J x 10-9 0.8538 (24) -2Pa2(Pb2-Pc2) K x 10-8 0.957 (17) P2 F [5.56622] (1/2)(1-cos3) V3 158.5748 (44) PaP  unitless 0.0457062 (35) P 2 (Pa Pb + Pb Pa) Dab x 10-5 0.638 (35) (1-cos3)Pa2 k5 x 10-2 0.32990 (94) (1-cos3)P2 FV x 10-3 -0.147 (75) (1-cos3)(Pb2-Pc2) c2 x 10-4 -0.7546 (79) (1-cos3){Pa,Pb} dAB -0.0000973 (60) PgPa P2 Lv -0.0000001372 (44) P4Pa2 HJK x 10-13 0.270 (40) Current fit: J’’ = 75 18 floated torsion-rotation parameters F constant fixed to the value obtained by XIAM (Velino B., Maris A., Melandri S., Caminati W. J Mol. Spectrosc. 256 (2009) 228 – 231.) a In the rho-axis system

CP-FTMW + MMW spectra: results Operatora Constant Unit Value Pa2 A cm-1 0.3026567 (31) Pb2 B 0.0848837 (11) Pc2 C 0.061139775 (45) {Pa,Pb} Dab -0.047932 (45) {Pa,Pc}(sin3) Dac 0.000639 (13) -P4 DJ x 10-8 0.52753 (48) -Pa4 DK x 10-6 0.31561 (46) -2P2(Pb2-Pc2) J x 10-9 0.8538 (24) -2Pa2(Pb2-Pc2) K x 10-8 0.957 (17) P2 F [5.56622] (1/2)(1-cos3) V3 158.5748 (44) PaP  unitless 0.0457062 (35) P 2 (Pa Pb + Pb Pa) Dab x 10-5 0.638 (35) (1-cos3)Pa2 k5 x 10-2 0.32990 (94) (1-cos3)P2 FV x 10-3 -0.147 (75) (1-cos3)(Pb2-Pc2) c2 x 10-4 -0.7546 (79) (1-cos3){Pa,Pb} dAB -0.0000973 (60) PgPa P2 Lv -0.0000001372 (44) P4Pa2 HJK x 10-13 0.270 (40) New laboratory data up to 360 GHz principal axis-system New set of the spectroscopic constants Current fit: J’’ = 75 18 floated torsion-rotation parameters F constant fixed to the value obtained by XIAM Search for the vinyl acetate in Orion KL (Velino B., Maris A., Melandri S., Caminati W. J Mol. Spectrosc. 256 (2009) 228 – 231.) a In the rho-axis system

Molecular Astrophysics Acknowledgements Grants CTQ 2010- 19008, AYA 2009-07304 and AYA 2012-32032 Grant VA070A08 CSD 2009-00038 Molecular Astrophysics …and all the members of the