COMPREHENSIVE ANALYSIS OF INTERSTELLAR Grupo de Espectroscopia Molecular, Lab. De Espectroscopia y Bioespectroscopia, Edificio Quifima, Unidad Asociada CSIC, Universidad de Valladolid, Valladolid, Spain COMPREHENSIVE ANALYSIS OF INTERSTELLAR Iso-PROPYL CYANIDE UP TO 480 GHz Lucie Kolesniková, Elena R. Alonso, Carlos Cabezas, Santiago Mata, José L. Alonso International Symposium on Molecular Spectroscopy, June 20  24, 2016 Champaign-Urbana, Illinois, USA

Research in our group is devoted to : *Rotational Spectra of Molecules of Astrophysical Interest The combination of Lab. Data and Radioastronomy provides a power capability for the detection and conclusive identification of molecular species in the ISM Frequency Domain Stark Modulation MW: 8- 170 GHz Millimeter and Submillimeterwave : 50- 1000 GHz *Conformation and Structure of Biomolecules. Rotational studies of solid biomolecules by FTMW spectroscopy in a supersonic expansion combined with laser ablation techniques of vaporization. Time Domain MB-FTMW: 5- 26 GHz LA-MB-FTMW : 2- 10 GHz LA-MB-FTMW : 4-26 GHz CP-FTMW: 2- 40 GHz

Introduction and motivation Branched alkyl molecule detected in the hot core of Sgr B2(N)a Its detection based in the identification of about 50 ground state rotational transitions found between 84 and 111 GHz (ALMA survey) a A. Belloche, R. T. Garrod, H. S. P. Müller, and K. M. Menten: Science 345 (2014) 1584.

Previous rotational studies Authors Year Freq. range Description G. E. Herbericha 1967 5  30 GHz Stark spectroscopy: GS, rotational and 14N nuclear quadrupole coupling constants J. R. Durig  Y. S. Lib 1974 26  40 GHz Stark spectroscopy: GS and three excited vibrational states, dipole moment, structural parameters H.S.P. Müller et al.c 2011 6  20 GHz FTMW spectroscopy: accurate 14N nuclear quadrupole coupling constants 37  600 GHz FM + Stark spectroscopy: accurate GS rotational and cent. distortion constants, dipole moment revised no excited vibrational states in the MMW region, no 13C species a H. S. P. Müller et. al: J. Mol. Spectrosc. 367 (2011) 100; b J. R. Durig and Y. S. Li: J. Mol. Struct. 21 (1974) 289; c G. E. Herberich: Z. Naturforschg. A 22 (1967) 543.

Experimental procedure Stark-modulation spectra Ab initio calculations GS and excited vibrational states assignments : preliminary set of spectroscopic contants mm and subm-mw spectra Assignments Loomis-Wood plot technique Global Fit (A, B, C, DJ, DJK, DK, …)

Experimental procedure Stark-modulation spectra Ab initio calculations GS and excited vibrational states assignments : preliminary set of spectroscopic contants Line survey mm and subm-mw spectra Detection? Assignments Loomis-Wood plot technique Synthesized spectrum MADEX code Global Fit (A, B, C, DJ, DJK, DK, …)

1. Stark-modulation rotational spectra MW Source Stark Cell Detector (50  75 GHz) n t I Stark Modulation n

Stark-modulation rotational spectra (300 Vcm1) ma = 4.0219 (50) D G.S.

Stark-modulation rotational spectra ma = 4.0219 (50) D G.S. Vibrational satellite pattern

Stark-modulation rotational spectra Trans-propenal Pure rotational spectra in the ground state and vibrational excited states Ground State

Vibrational satellite analysis Ab initio calculations (MP2/6-311++G(d,p), B3LYP/6-311++G(d,p),…) vibrational frequencies (14 A’  10 A’’ normal modes) predictions of rotation-vibration coefficients five normal modes below 400 cm1 n30 n17 n29 190 cm1, bending (A’’) 219 cm1, torsion (A’)  223 cm1, torsion (A’’) n16 n15 353 cm1, scissoring (A’) 283 cm1, bending (A’)

Experimental procedure Stark-modulation spectra Ab initio calculations GS and excited vibrational states assignments : preliminary set of spectroscopic contants mm and subm-mw spectra Assignments Loomis-Wood plot technique Global Fit (A, B, C, DJ, DJK, DK, …)

Millimeter and Submillimeter Wave Spectrometer Double pass configuration (50 – 170 GHz)

Millimeter and Submillimeter Wave Spectrometer Double pass configuration (50 – 170 GHz)

Millimeter and Submillimeter Wave Spectrometer Double pass configuration (50 – 170 GHz)

Millimeter and Submillimeter Wave Spectrometer Double pass configuration (50 – 170 GHz)

Millimeter and Submillimeter Wave Spectrometer Single pass configuration (170 – 1000 GHz)

Millimeter and Submillimeter Wave Spectrometer Single pass configuration (170 – 1000 GHz)

Millimeter and Submillimeter Wave Spectrometer Single pass configuration (170 – 1000 GHz) 80 – 480 GHz room temperature 12 mbar

Iso-propyl cyanide: MMW + Stark spectrum Loomis-Wood type display facilities of the AABS package of Kisiel ncent(MHz) Dn (MHz)

Iso-propyl cyanide: MMW + Stark spectrum Loomis-Wood type display facilities of the AABS package of Kisiel ncent(MHz) FM spectra (80  480 GHz) Stark spectra (50  75 GHz) Dn (MHz)

Iso-propyl cyanide: MMW + Stark spectrum ncent(MHz) G.S. Dn (MHz)

Iso-propyl cyanide: MMW + Stark spectrum ncent(MHz) v30 = 1 v15 = 1 G.S. ? v16 = 1 v30 = 2 ? v29 = 1 v17 = 1 ? Dn (MHz)

Iso-propyl cyanide: MMW + Stark spectrum G.S. ve = 1 vd = 1 va = 1 vd = 2 ? ncent(MHz) vg = 1 v30 = 1 v17 = 1 v16 = 1 v15 = 1 v30 = 2 v29 = 1 v30 = 3 Dn (MHz)

Iso-propyl cyanide: Analysis S-reduced Hamiltonian (Ir-representation) up to the sixth order

Iso-propyl cyanide: Analysis S-reduced Hamiltonian (Ir-representation) up to the sixth order Perturbations observed in several excited vibrational states e.g. n17 (A’) n29 (A’’)

Iso-propyl cyanide: Analysis S-reduced Hamiltonian (Ir-representation) up to the sixth order Perturbations observed in several excited vibrational states v17 = 1 Ka = 2, 3 e.g. Ka = 1, 2 (nv  nGS) / (J’’ + 1) (MHz) Ka = 1, 2 Ka = 0, 1 v29 = 1 n17 (A’) n29 (A’’) J’’ + 1

Conclusions and future plan Stark and MMW spectra of iso-propyl cyanide measured and analyzed between 26 and 480 GHz 10 excited vibrational states identified (and more line sequences observed) Perturbations between individual states observed interactions planned to be analyzed 13C species observed in the natural abundance analysis in progress

Molecular Astrophysics Acknowledgements CSD 2009-00038 Molecular Astrophysics Grants CTQ 2013- 40717-P and AYA 2012-32032 Grant VA070A08 (FP/2007-2013) / ERC-2013-SyG Grant No. 610256 …and all the members of