Solving the Tautomeric Equilibrium of Purin hrough the

Solving the Tautomeric Equilibrium of Purin hrough the Analysis of the Complex Hyperfi Structure of the Four 14 N Nuclei Laura B. Favero, Iciar Uriarte, Lorenzo Spada, Patricia E cija, Camilla Calabrese, Walther Caminati and Emilio J. Cocinero Illinois, June 20, 2016

PURINE STRUCTURE: Heterocyclic aromatic organic compound : : Pyrimidine : : Imidazole BIOLOGICAL: Mainframe of DNA / RNA bases : : Adenine : : Guanine Other notable purines SYNTHESIS: In vivo many organisms metabolize Laboratory synthesis 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei INTRODUCTI ON

INTRODUCTI ON PURINE BASES Purine Theobromine Guanine Caffeine Adenine Hypoxanthine Uric acid 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei Xanthine Isoguanine

INTRODUCTI ON PYRIMIDE BASES Thymine Uracil Cytosine 1 tautormer 2 tautormers 5 tautormers PURINE BASES Several tautomers Complex structure hyperfine Adenine Guanine 4 tautormers No hyperfine analysis 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

INTRODUCTI ON PURINE N(9)H N(7)H ü Solid state a Solution b ü ü Gas phase a Acta Crystallogr. , 19, 573 (1965) b J. Am. Chem. Soc. , 104, 3162 (1982) 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

INTRODUCTI ON GAS PHASE Experiments N(9)H N(7)H UV PES study (indirectly) Matrix isolation Millimeter wave (heating) - Caminati Chem. Phys. Lett. , 251, 189 (1996) Theory Dominant species (15 -40 k. Jmol-1) Motivation Detection of high energy tautomer N(7)H Analysis of complicated hyperfine structure due to four quadropolar nuclei 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

INSTRUMENTAT ION FT-MW Electronic tower Vacuum chamber and Fabry-Perot resonator Laser vaporization system PCCP, 12486 (2010) Angew. Chem. Int. Ed, 51, 3119 (2012) Resolution: ~ 3 k. Hz | ~0. 0000001 cm-1 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

INSTRUMENTAT ION CP-FTMW Arbitrary Wave generator Chamber Scope Amplifier Resolution: ~ 10 k. Hz | Broadband (7 -18 GHz) 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

INSTRUMENTAT ION CP-FTMW Chamber Resolution: ~ 10 k. Hz | Broadband (7 -18 GHz) 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

RESULT S MP 2/6 -311++G(d, p) EN(7)H, 0 EN(7)H, e N(7)H 15. 9 k. J·mol-1 EN(9)H, 0 N(9)H 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei 16. 9 k. J·mol-1 EN(9)H, e

RESULT S MP 2/6 -311++G(d, p) A, B, C / MHz N 1: aa, bb, cc / MHz N 3: aa, bb, cc / MHz N(7)H N 7: aa, bb, cc / MHz N 9: aa, bb, cc / MHz A, B, C / MHz |μa|, |μb| / D N 1: aa, bb, cc / MHz N 3: aa, bb, cc / MHz N(9)H N 7: aa, bb, cc / MHz N 9: , bb, cc / 71 International Symposium on Molecular Spectroscopyaa Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex MHz Hyperfine Structure of the Four N Nuclei st 14 4101, 1745, 1224 -3. 553, 0. 367, 3. 187 1. 427, -4. 633, 3. 207 1. 680, 1. 488, -3. 168 1. 373, -3. 379, 2. 005 4099, 1750, 1227 3. 1, 5. 0 -3. 502, 0. 381, 3. 121 1. 659, -4. 663, 2. 630 1. 567, -3. 171, 1. 605 1. 432, 1. 508, -2. 940

PARAMETERS A / MHz B / MHz C / MHz [N 1] aa / MHz bb / MHz cc / MHz [N 3] aa / MHz bb / MHz cc / MHz [N 7] aa / MHz bb / MHz cc / MHz [N 9] aa / MHz bb / MHz cc / MHz c / uÅ / k. Hz N RESULT S N(9)H Theory 4099 1750 1227 N(7)H Experiment 4125. 8895(2) 1755. 1720(1) 1231. 55819(6) -3. 343(5) 0. 440(6) 2. 904(6) 1. 673(7) -4. 229(9) 2. 555(9) 1. 547(7) -3. 379(9) 1. 833(9) 1. 489(5) 1. 495(7) -2. 985(7) -0. 0693(3) 4. 8 292 Experiment 4127. 3813(3) 1749. 7594(3) 1229. 42760(7) -3. 560(15) 0. 566(17) 2. 994(17) 0. 695(11) -2. 744(20) 2. 049(20) 1. 254(11) 1. 532(16) -2. 786(16) 1. 541(11) -3. 239(18) 1. 699(18) -0. 2046(4) 4. 9 113 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei Theory 4101 1745 1224

RESULT S SPECTRUM Experiment 221 110 N(9)H 13608 13610 Simulation 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei 13612

PARAMETERS A / MHz B / MHz C / MHz [N 1] aa / MHz bb / MHz cc / MHz [N 3] aa / MHz bb / MHz cc / MHz [N 7] aa / MHz bb / MHz cc / MHz [N 9] aa / MHz bb / MHz cc / MHz c / uÅ / k. Hz N RESULT S N(9)H Theory 4099 1750 1227 N(7)H Experiment 4125. 8895(2) 1755. 1720(1) 1231. 55819(6) -3. 343(5) 0. 440(6) 2. 904(6) 1. 673(7) -4. 229(9) 2. 555(9) 1. 547(7) -3. 379(9) 1. 833(9) 1. 489(5) 1. 495(7) -2. 985(7) -0. 0693(3) 4. 8 292 Experiment 4127. 3813(3) 1749. 7594(3) 1229. 42760(7) -3. 560(15) 0. 566(17) 2. 994(17) 0. 695(11) -2. 744(20) 2. 049(20) 1. 254(11) 1. 532(16) -2. 786(16) 1. 541(11) -3. 239(18) 1. 699(18) -0. 2046(4) 4. 9 113 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei Theory 4101 1745 1224

RESULT S QUADRUPOLE aa, bb, cc x, y, z (PAS, physical meaning) Planar y = cc 1. 833(9) 2. 904(6) 2. 994(17) -2. 786(16) -2. 985(7) 2. 049(20) 2. 555(9) N(9)H Experimental cc in MHz -2. 704(4) 2. 228(8) Pyrrole 1. 699(18) N(7)H 3. 5584(7) -2. 559(9) Imidazole 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei Pyrimidine

RESULT S POPULATION x 30 221 110 N(9)H N(7)H N(9)H POPULATION RATIO: = 40 N(7)H ΔE 0, 0 = 9 (1) k. Jmol-1 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei (15)

RESULT S Laura B. Favero Iciar Uriarte Lorenzo Spada Patricia Écija Camilla Calabrese Walther Caminati Emilio J. Cocinero J. Phys. Chem. Lett. , 7, 1187 (2016) 71 st International Symposium on Molecular Spectroscopy Solving the Tautomeric Equilibrium of Purine through Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei

Laura B. Favero, Iciar Uriarte, Lorenzo Spada, Patricia E cija, Camilla Calabrese, Walther Caminati and Emilio J. Cocinero Solving the Tautomeric Equilibrium of Purine through the Analysis of the Complex Hyperfine Structure of the Four 14 N Nuclei