Update of the analysis of the pure rotational spectrum of excited vibrational states of CH 3 CH 2 CN Adam Daly, John Pearson, Shanshan Yu, Brian Drouin Jet Propulsion Laboratory Celina Bermúdez, José Luis Alonso Universidad de Valladolid, Grupo de Espectroscopia Molecular 6/23/2015TG- 061

Astronomy Research Demands As Pepe Cernicharo stated to me “analyze, assign and publish everything for every molecule”. 6/23/2015TG- 062

C 2 H 5 CN Ethyl Cyanide 6/23/2015TG- 06 Literature Daly, A. M., Bermúdez, C., & López, A, B. Tercero 2, J. C. Pearson 3, N. Marcelino 4, J. L. Alonso 1, and J. Cernicharo , ApJ, 768, 81 v12, v20 Fukuyama Y, Omori K, Odashima H, Takagi K, Tsunekawa S: Analysis of rotational transitions in excited vibrational states of propionitrile (C2H5CN). Journal of Molecular Spectroscopy 1999, 193(1): V13-v21-v20. Mehringer DM, Pearson JC, Keene J, Phillips TG: Detection of vibrationally excited ethyl cyanide in the interstellar medium. Astrophysical Journal 2004, 608(1): V13-v21 Brauer CS, Pearson JC, Drouin BJ, Yu SS: NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE. Astrophysical Journal Supplement Series 2009, 184(1): gs Duncan, N.E., Janz, G.J. Molecular Structure and Vibrational Spectroscopy of Ethyl Cyanide, Journal of Chemical Physics gs Mader H, Heise HM, Dreizler H: MICROWAVE-SPECTRUM OF ETHYL CYANIDE - R0-STRUCTURE, NITROGEN QUADRUPOLE COUPLING-CONSTANTS AND ROTATION-TORSION-VIBRATION INTERACTION. Z Naturfors Sect A-J Phys Sci 1974, A 29(1): Gs, v13-v21 Laurie VW: MICROWAVE SPECTRUM AND INTERNAL ROTATION OF ETHYL CYANIDE. Journal of Chemical Physics 1959, 31(6): Lerner RG, Dailey BP: MICROWAVE SPECTRUM AND STRUCTURE OF PROPIONITRILE. Journal of Chemical Physics 1957, 26(3):

HOT CORE COMPONENT 1 (4’’, 5 Km s -1 respect to LSR, 5 Kms -1 line width ) HOT CORE COMPONENT 3 (25’’, 3 Km s -1 respect to LSR, 22 Kms -1 line width ) Parameters of the Orion-KL region that best simulate the emission line profile of CH 3 CH 2 CN using the “Excitation and transfer code” (J. Cernicharo, 2012) Temperature and column density derived from analysis of rotational transitions of CH 3 CH 2 CN define the physical and chemical conditions of the Orion-KL region. N (cm -2 )275 K130 K65 K N(CH 3 CH 2 CN g.s.) (cm −2 ) (3.0±0.9)x10 16 (8±2)x10 15 (3.0±0.9)x10 15 N(CH 3 CH 2 CN ν 13 =1/ ν 21 =1) N(CH 3 CH 2 CN ν 20 ) (cm −2 ) N(CH 3 CH 2 CN ν 12 ) (cm −2 ) (4 ±1)x10 15 (1.7 ±0.5)x10 15 (6 ±3)x10 14 (1.1±0.3)x10 15 (4±1)x10 14 (1.6±0.5)x10 14 (4±1)x10 14 (1.7±0.5)x10 14 (6±3)x10 13 N( 13 CH 3 CH 2 CN) (cm −2 ) N(CH 3 13 CH 2 CN) (cm −2 ) N(CH 3 CH 2 13 CN) (cm −2 ) (7 ±2)x10 14 (2±1)x10 14 (1.9±0.6)x10 14 (5±3)x10 13 (7±2)x10 13 (1.7±0.8)x10 13 Ethyl cyanide ORION-KL Nebula CH 3 CH 2 CN LABORATORY MEASUREMENTS – RADIO ASTRONOMICAL OBSERVATIONS LABORATORY MEASUREMENTS – RADIO ASTRONOMICAL OBSERVATIONS A-CH 2 DCH 2 CN, S-CH 2 DCH 2 CN, CH 3 CHDCN) “upper limit for the N (cm -2 ) (tentative detection)” HOT CORE COMPONENT 2 (10’’, 3 Km s -1 respect to LSR, 13 Kms -1 line width ) 6/23/2015TG- 064

Frequency range 6/23/2015TG- 06 SourceFrequency Range Valladolid Stark GHz Valladolid FM GHz, Toyoma Line list GHz OSU Line FASST a GHz JPL , GHz JPL , GHz, THz a S. M. Fortman, I. R. Medvedev, C. F. Neese, and F. C. De Lucia. ApJ725, 1682 (2010). 5

6/23/2015TG- 06 StateVibrational E E Lower Range J Ave Energy – G.S. Energy Predicted Energy** Predicted anharmonic energyPercent anharmonic GS v v * *two points removed ** MP2/aug-cc-pVTZ K=0&1 Data sets in the De Lucia Temperature Study 6

2v 13 K 0&1 v 20 K 0&1 2v 21 K 0&1 V 13 +V 21 K 1&2 2v 13 K 1&2 2v 21 K1&2 v 20 K 2&3 v 20 K 1&2 V 13 +V 21 K 0&1 2v 13 K 2&3 2v 21 K 2&3 6/23/2015TG- 067 Assignments of low K a series for  13, 2 21, Calc Energy cm -1 A”A’A”A’ Coriolis(a,b)Fermi strongCoriolis(a,b) Coriolis(a,b)Fermi (e-e) weak v 13 Coriolis(a,b)

6/23/2015TG- 06 K a =0&1 series 3 state fit v 20+ v 21 v 20+ v 13 v 12 8 Calc Energy cm -1 A’A”A’ CoriolisFermi v 13 Coriolis v 21

Signal Strength 6/23/2015TG- 06 v ,54 →57 5, ,59 →59 2,58 A/E v 20 +v ,59 →59 1,58 A/E G.S, 57 6,51 →56 6,50 9

6/23/2015TG K a = 3 perturbation 20 K a =3 with 2 13 and 2 21 K a =0 & 1 Kc=odd interaction (a,b) symmetry Perturbations in v 20 10

6/23/2015TG General Philosophy Construct a Hamiltonian to fit the Fukuyama, et al. dataset Is there splitting in 20 because of the perturbation?

6/23/2015TG The 20 splitting in the b-dipole can it be fit? Do we need an interaction Coriolis or Fermi with 2 13,2 21 or ?

6/23/2015TG Building the interaction Hamiltonian in SPFIT for 20 (A″) Coriolis or Fermi interaction 1.Attempt an isolated state fit 2.Build in approximate interaction terms

6/23/2015TG : : : : : : / : / : : : : : : : : / / : : / / / / / : MICROWAVE lines fitted lines lines RMS RMS ERROR J range Ka range total dv=0 dv.ne.0 UNFITTD e>900 v"= v"= v"= total: This fit has opened the door to the THz analysis of the b-dipole transitions

6/23/2015TG StateEnergy A state v MHz v MHz v MHz Summary of A-E energy difference

6/23/2015TG Using this current model, we have assigned over 800 transitions and plan to analyze the perturbations at K=3,4 and at high K of 20 with the other states 13 CH 3 CH 2 CN, CH 3 13 CH 2 CN and CH 3 CH 2 13 CN A- state has been assigned for 21 /  13,  12 and 20 and currently fitting 21 /  13 up 1 THz 13 C isotopes from University of Lille. More updates: These fits will be published soon!

6/23/2015TG Acknowledgements Caltech- JPL John Pearson Brian Drouin Tim Crawford GEM-Valladolid José Luis Alonso Jose Cernicharo Celina Bermúdez Alicia López Professor Kisiel