Daniel A. Obenchain, Derek S. Frank, Stewart E. Novick, The Position of Deuterium in HOD-N2O as Determined by Structural and Nuclear Quadrupole Coupling Constants Daniel A. Obenchain, Derek S. Frank, Stewart E. Novick, William Klemperer

Previous Microwave Study J. Chem. Phys. 97, 2861 (1992)

Previous Microwave Study MBER experiment Measured deuterium isotopologues Could not fully resolve the 14N hyperfine splitting Details the internal motion of water in the complex, and compares it to the iso-electronic H2O-CO2 complex

Spring/Summer 2014 Michel Herman Bill Klemperer Stew Novick

A More Recent Study

Reported Constants from 1992 study aZolandz, D.; Yaron, D.; Peterson, K. I.; Klemperer, W. Journal of Chemical Physics 1992, 97, 2861.

Where is the deuterium in HOD-N2O? or Quasi-Parallel Quasi-Perpendicular

Experiment Balle-Flygare Fourier transform microwave spectrometer 6-18GHz 1.5% N2O in 1.0-1.2 at Ar was bubbled through a sample of water H2O and D2O were combined to produce a 1:2:1 mixture of H2O:HDO:D2O

212 – 111 Transition of HOD···N2O Splitting from 4 sources Doppler doubling 1 deuterium quadrupolar nucleus 2 nitrogen quadrupolar nuclei

Parameters for H2O-N2O Previous MW Studya This Work State A State B A (MHz) 12622.595(203) 12605.001(77) 12621.798(1) 12604.5274(9) B (MHz) 4437.422(47) 4437.978(32) 4437.2542(7) 4437.5038(6) C (MHz) 3264.962(47) 3264.302(32) 3264.3845(5) 3264.7369(3) ΔJ (kHz) 30.8(12) 23.35(4) 23.61(3) ΔJK (kHz) 243.0(32) 284.6(2) 283.1(1) ΔK (kHz) 350 -206.6(6) -213.4(3) δJ (kHz) 8.6(3) 8.04(1) 8.685(9) δK (kHz)d 224.2(76) - χaa 14Ninner (kHz) 128(45)a 57(5) 65(3) χbb 14Ninner (kHz) -226(6) -235(3) χcc 14Ninner (kHz) 168(8) 169(4) χaa 14Nouter (kHz) 371 (130)a 346(3) 344(2) χbb 14Nouter (kHz) -807(6) -782(3) χ­­cc 14Nouter (kHz) 461(6) 438(4) N (lines) 66 58 RMS (kHz)f 4.8 2.2 aZolandz, D.; Yaron, D.; Peterson, K. I.; Klemperer, W. Journal of Chemical Physics 1992, 97, 2861.

HOD-N2O Hyperfine Constants HDO-NNO HDO-N15NO HDO-15NNO χaa 14Ninner (kHz) - 54(3) χbb 14Ninner (kHz) -279(9) χcc 14Ninner (kHz) 225(9) χaa 14Nouter (kHz) 319(3) χbb 14Nouter (kHz) -755(6) χcc 14Nouter (kHz) 436(6) χaa D (kHz) -107(6) -103(19) χbb D (kHz) 261(9) 251(31) χcc D (kHz) -154(11) -148(37)

HOD-N2O Hyperfine Constants HDO-NNO HDO-N15NO HDO-15NNO χaa 14Ninner (kHz) 53(7) - 54(3) χbb 14Ninner (kHz) -235(10) -279(9) χcc 14Ninner (kHz) 181(12) 225(9) χaa 14Nouter (kHz) 332(3) 319(3) χbb 14Nouter (kHz) -762(4) -755(6) χcc 14Nouter (kHz) 430(5) 436(6) χaa D (kHz) -95(6) -107(6) -103(19) χbb D (kHz) 230(9) 261(9) 251(31) χcc D (kHz) -134(11) -154(11) -148(37)

The 212 - 111 transition for HDO-14N14NO J + IN,inner = F1 F1 + IN,outer = F2, F2 + ID = F F1’, F2’, F’ – F1’’, F2’’, F’’

HDO-N2O constants Previous MW Studya Previous IR Studyb This work HDO-NNO HDO-N15NO HDO-15NNO A (MHz) 12512.417(158) 12512.939(294) 12512.583(1) 12533.0(1) 12149.11(6) B (MHz) 4267.344(41) 4267.653(84) 4267.057(1) 4238.978(1) 4221.5366(5) C (MHz) 3166.356(41) 3166.231(92) 3166.6575(5) 3150.925(1) 3118.2372(5) ΔJ (kHz) 26(2) 34.0(8) 22.18(6) 17.6(1) 18.87(5) ΔJK (kHz) 157(19) 256(20) 207.1(2) [207.0] ΔK (kHz) -111(31) -23(57) -115.9(7) [-115.4] δJ (kHz) 12.4(48) 11.0(4) 7.05(2) [7.06] δK (kHz) 123(32) 125(22) - N (lines) 12 98 13 15 RMS (kHz)6 181 5.2 4.5 0.8 aZolandz, D.; Yaron, D.; Peterson, K. I.; Klemperer, W. Journal of Chemical Physics 1992, 97, 2861. bFoldes, T.; Lauzin, C.; Vanfleteren, T.; Herman, M.; Lievin, J.; Didriche, K. Molecular Physics 2015, 113, 473.

Kraitchman Coordinate Determination From Data in Originala This Experiment ab initio |a| |b| a b H perpendicular 2.7257(5) 0.5797(5) 2.8 -0.4 H parallel 2.0949(7) 0.5703(7) 2.0929(5) 0.568(3) 1.9 0.8 N inner   0.921(2) 0.260(6)i -0.9 0.0 N outer 1.115(2) 1.118(1) -1.2 -1.1 a b aZolandz, D.; Yaron, D.; Peterson, K. I.; Klemperer, W. Journal of Chemical Physics 1992, 97, 2861.

rm(2) Structure of H2O-N2O

HOD Quadrupole Tensor a b D H Quadrupole tensor of D in DOH from Puzzarini (units in kHz) χ = 277.2(15) 114.7 -105.6(35) -171.6(35) Thaddeus, P.; Loubser, J. H. N.; Krisher, L. C. Journal of Chemical Physics 1964, 40, 257 Cazzoli, G. L., V.; Puzzarini, C. Gauss, J. In 69th International Symposium on Molecular Spectroscopy Champaign-Urbana, 2014 Puzzarini, C., hf parameters of HD(16)O, Private Communication

Rotation To Experimenal Values b a b D H Quadrupole tensor of D in DOH from Puzzarini (units in kHz) χ = 277.2(15) 114.7 -105.6(35) -171.6(35) Quadrupole tensor of D in DOH-NNO from this work (units in kHz) χ = -95(6) 230(9) -134(11) Rotation that reproduce experimental DOH-N2O (units in kHz) Rotation angles χ = -94 -126 38 φ = -87.4° 230 -120 θ = -16.7° -136 χ = 0°

Rotation to the Perpendicular Position Rotation to the parallel position (units in kHz) χ = -94 230 -136 Quadrupole tensor of D in DOH from Puzzarini (units in kHz) χ = 277.2(15) 114.7 -105.6(35) -171.6(35) a' b a b D H Rotation to the perpendicular position (units in kHz) χ = 275 -103 -172

Observation of Perpendicular Deuterium Herman and co-workers found a local minimum in their ab initio studies for the deuterium in the perpendicular position 7 cm-1 higher in energy than deuterium in the parallel position Searches completed using the isotopic shifts from the rm(2) structure as a starting point No lines found as of yet a b H D

Conclusion In the HOD-N2O complex measured in by Klemperer in 1992, the measured structure was that of a deuterium occupying the quasi- parallel position Conformation by structure fit and quadrupole tensor analysis

Acknowledgements Michel Herman and his collaborators at Université Libre de Bruxelles Cristina Puzzarini at the Università di Bologna NSF CNS-0619508 for cluster funding at Wesleyan The Novick/Pringle/Cooke Group members