FOUR STRUCTURES OF TARTARIC ACID REVEALED IN THE GAS PHASE V. CORTIJO, V. DIEZ, E.R. ALONSO, S. MATA, JOSE L. ALONSO Lab. Espectroscopia y Bioespectroscopia Edificio de Investigación QUIFIMA Area de Química-Física. Parque Científico. Unidad Asociada CSIC. Universidad de Valladolid Valladolid, Spain International Symposium on Molecular Spectroscopy 72nd MEETING - JUNE 19-23, 2017 - CHAMPAIGN-URBANA, ILLINOIS

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 + MMW: 8  110 GHz Frequency Modulation MMW and Sub-MMW : 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: 2  26 GHz LA-MB-FTMW: 2  10 GHz LA-MB-FTMW: 4  26 GHz CP-FTMW: 2  40 GHz

Cork of Ribera de Duero WINE TARTARIC ACID MOTIVATION OF THE WORK The stereoisomer (R,R) is obtained exclusively from the natural residues in winemaking. Cork of Ribera de Duero WINE The enantiomerism phenomenon discovered by Louis Pasteur (1857) through enantioselective tartrate fermentations placed to tartaric acid as one of the most important organic compound. Properties: Natural Antioxidant, Preservative and acidifying. Relevant Industrial applications: Organic and pharmaceutical chemistry Cosmetics Food and beverage industries (R,R) Tartaric acid m.p. 174C

The naturally occuring form of tartaric acid Their properties are the result of the great hability of tartaric acid to create varios types of hydrogen bonds, closely related to its structure and the presence of multiple OH within it.  Two chirality centers Pair of enantiomers Meso compound (R,R) Tartaric acid (S,S) Tartaric acid The naturally occuring form of tartaric acid

STRUCTURAL INFORMATION AVAILABLE FOR (R,R) TARTARIC ACID Condensed phases : X-Ray F. Stern and C. A. Beevers. The crystal structure of tartaric acid. Acta Crystallogr. 1950, 3, 341. Y. Okaya, N. R. Stemple and M.I. Kay. Refinement of the structure of D-Tartaric acid by X-Ray and neutron diffraction. Acta Cryst. (1966). 21, 237. THz-vibrational spectroscopy Elewina M. Witko and Timothy M. Korter. Investigation of the low-frequency vibrations of the crystalline Tartaric acid using terahertz spectroscopy and solid-state density functional-theory. J. Phys. Chem. A. 2011, 115, 10052-10058. P.L. Polavarapu, C. S. Ewig and T. Chandramouly. Conformations of tartaric acid and its esters. J. Am. Chem. Soc., 1987, 109, 7382-7386. Jacek Gawronski, Krystyna Gawronska, Pawel Skowronek, Urzsula Rychlewska, Beata Warzajtis, Jacek Rychlewski, Marcin Hoffmann and Agnieszka Szarecka. Factors affecting conformation of (R,R) Tartaric acid ester, amide and nitrile derivates. X-Ray diffraction, Circular dichroism, nuclear magnetic resonance and ab initio studies Tetrahedrom, Vol. 53, Nº 17, 6113-6144, 1997. Vibrational circular dichroism H-NMR C-NMR José Ascenso and Victor M. S. Gil. The conformations of tartaric acids in aqueous solution studied by 1H and 13C nuclear magnetic resonance. Can. J. Chem., 58, 1376 (1980). Vibrational Raman Optical Activity L. D. Barron. Raman optical activity of tartaric acid and related molecules. Tetrahedron, Vol 34, 607-610 (1978). L. D. Barron, A. R. Gargaro and L. Hecht. Experimental and ab initio theoretical vibrational Raman optical activity of tartaric acid. Spectrochimica Acta, Vol. 48A, Nº 8, 1051-1066, 1992.

BECAUSE IT IS A SOLID WITH HIGH MELTING POINT (174C) TARTARIC ACID Condensed phases results are only consistent with the existence of a trans configuration Gauche Trans G- T G+ DESPITE THE IMPORTANT ROLE OF TARTARIC ACID, THERE EXISTS NO DETAILED EXPERIMENTAL INFORMATION ABOUT ITS CONFORMATIONAL BEHAVIOR. WHY? BECAUSE IT IS A SOLID WITH HIGH MELTING POINT (174C)

Narrowband LA-MB-FTMW Experimental Approach Laser Ablation Vaporization Spectroscopic Characterization FT-MW Supersonic Expansion Gas Phase Isolation Narrowband LA-MB-FTMW Broadband LA-CP-FTMW

Our group and sugars, dipeptides, nucleosides….etc: D-xylose. Phys.Chem. Chem. Phys., 2013, 15, 18243 Erythrose. Chem. Commun., 2013, 49, 10826 2-Deoxy-D-ribose. Angew. Chem. 2013, 125, 1 – 7 D-fructopyranose. ChemPhysChem., 2013, 14, 893 – 895 D-glucose. Chem. Sci., 2014, 5, 515 D-glucosamine. Phys. Chem. Chem. Phys., 2014,16, 23244-23250 α-D-galactose. Chem. Commun., 2015, 51, 10115-10118 Ketohexoses . Chem.E.J. 22, 16829-16837 (2016) Uridine. Angew.Chem.Int.Ed. 54, 2991-94 (2015) Exoanomeric effect. J. Phys.Chem.Lett., 7, 845−850 (2016) Gycine-Glycine. Angew.Chem.Int. Ed. 2017, 56,6420 –6425 between others.....

FABRY-PEROT RESONATOR Broadband Laser Ablation CP-FTMW CP-FT-MW Vaccum Chamber FABRY-PEROT RESONATOR Picosecond Laser Picosecond LASER CP-FTMW Spectrometer Valladolid 2016 Valladolid 2012

EXPERIMENT : LA-CP-FTMW THE EXPERIMENT Diffusion pump Jet Laser

Broadband Fourier Transform: Operation Gas pulse Jet Ne Laser pulse Solid sample Rotary Diffusion pump Laser Nd:YAG laser

Broadband Fourier Transform: Operation CP-FTMW spectrometer Gas pulse Molecular emission Ne Laser pulse Chirped MW pulse Rotary Diffusion pump Detection

Broadband Fourier Transform: Operation CP-FTMW spectrometer Gas pulse Molecular emission Ne Laser pulse Chirped MW pulse Rotary Diffusion pump Detection Detection Frequency-domain Time-domain FT

LA-CP-FTMW Laser Jet

Chirped MW pulse Detection Gas pulse Laser pulse Jet Chirped MW pulse Detection Time-domain Frequency-domain FT

BROADBAND ROTATIONAL SPECTRA OF (R,R) TARTARIC ACID Strong progressions of c-type R branch transitions were easily identified in the spectrum . 3 2,1 ← 2 1,1 2 2,0 ← 1 1,0 2 2,1 ← 1 1,1   3 2,2 ← 2 1,2  J+12,J ← J1,J J+12,J-1 ← J1,J-1 3 1,2 ← 2 0,2 4 1,3 ← 3 0,3 5 1,4 ← 4 0,4   J+11,J ← J0,J C2 symmetry conformer? Selection rules

C2 C2 C2 A = T, G- o G+ C3 = s or a C2 = s or a C2 C3

Searching for C2 symmetry conformers  G+a,a and G+s,s Selection rules Much weaker new c-type R-branch progressions were identified . 2 2,0 ← 1 1,0  2 2,1 ← 1 1,1  3 2,1 ← 2 1,1 3 2,2 ← 2 1,2

C2 C2 G+s,s was not found

After remove all lines corresponding to the conformers Ts,s and G+a,a an exhaustive inspection of the broadband spectrum allow us to find new b-type R-branch lines attributable to a third rotamer III.  2 2,1 ← 1 1,0 2 2,0 ← 1 1,1 3 2,2 ← 2 1,1 3 2,1 ← 2 1,2 By an iterative process of fitting and prediction also a type R-branch rotational transitions were identified.  5 1,5 ← 4 1,4 5 0,5 ← 4 0,4 4 1,3 ← 3 1,2 5 1,4 ← 4 1,3

v Rotamer I  T s,s C2 C2 Rotamer II  G+a,a Rotamer III  G-a,s

After remove all lines corresponding to Ts,s G+a,a and G-a,s conformers a set of a type R-branch rotational transitions were assigned to rotamer IV By an iterative process of fitting and prediction also c-type R-branch transitions were measured.  6 1,6 ← 5 1,5 6 0,6 ← 5 0,5 6 1,5 ← 5 1,4 5 1,5 ← 4 1,4 5 0,5 ← 4 0,4  5 1,4 ← 4 1,3

Rotamer I  T s,s Rotamer II  G+a,a Rotamer III  G-a,s C2 C2 Rotamer II  G+a,a Rotamer III  G-a,s Rotamer IV  T s,a

Experimental Populations THE CONFORMATIONAL PANORAMA OF NATURAL OCCURING TARTARIC ACID Experimental Populations NTs,s : NG-a,s : NG+a,a : NTs,a = 1 : 0.4 : 0.3 : 0.2. T s,a (649 cm-1) OH…OH…OH…O cis-carboxylic 2 3 E G+ a,a (318 cm-1) 3 2 C2 OH…OH…O Close a six member ring 3 2 G- a,s (317 cm-1) OH…OH…OH…O OH…O close a seven member ring C2 3 2 T s,s (0 cm-1) Two OH…O Two cis-carboxylic Searching for more conformers …… THANKS FOR YOUR ATTENTION The most abundant species

Universidad de Valladolid Molecular Astrophysics Research Funded by: Contact : jlalonso@qf.uva.es Pr. José L. Alonso GEM , Edificio Quifima, Unidad Asociada CSIC, Universidad de Valladolid Valladolid, Spain POSTDOCTORAL POSITION AVAILABLE September 2017 Four years grant PhD thesis September 2017 www.gem.uva.es (FP/2007-2013) / ERC-2013-SyG Grant No. 610256 Grants CTQ 2013- 40717-P CTQ 2016- 76393- P CSD 2009-00038 Molecular Astrophysics Grants: VA175U13 VA077U16