1. Susanna Stephens H 2 O  AgF characterised by Rotational Spectroscopy

2. Objectives Systematic investigation B∙∙∙MX species where B is a Lewis base, M a coinage metal and X a halogen. Compare H 2 O ∙∙∙AgF and H 2 O ∙∙∙HF with H 2 O ∙∙∙AgCl and H 2 O ∙∙∙HCl Trends with previous work OC-MX and Ar-MX studies by Gerry and co-workers. H2S ∙∙∙MX and H 2 O ∙∙∙MX by Walker, Legon and co-workers

3. Balle-Flygare spectrometer To vacuum Stationary Mirror Adjustable mirror Fabry-Perot cavity containing standing wave and expansion of supersonic jet Adiabatic expansion of SF 6 / H 2 O / Ar Solenoid valve Gas line Silver rod and rotator 532 nm Nd:YAG laser Focusing lens To microwave circuits Rod rotator Laser arm Gas line attached to solenoid valve Microwave emission antenna Laser ablation nozzle A.C. Legon, in: G. Scoles (Ed.), Atomic and Molecular Beam Methods, vol. 2, Oxford University Press, Oxford, 1992 (Chapter 9) S. G. Batten, A. G. Ward, A. C. Legon, J. Mol. Struct., 300, 780, (2006)

4. Predicted structure First observed with H2O ··· HF Z. Kisiel, A.C. Legon, D.J. Millen, Proc. R. Soc. Lond. A 381, 419, (1982)  AgFO r AgO r AgF a

5. Analogous system H 2 O···AgCl and H 2 S···AgCl H 2 O···CuCl and H 2 S···CuCl studied subsequently are analogous H 2 O···AgCl and H 2 S···AgCl S. J. Harris et al., Ang.Chem.Int.Ed., 49, 181 (2010) H 2 O···AgCl and H 2 O···CuCl V. A. Mikhailov et al., J. Chem. Phys., 134, 134305 (2011) H 2 S···CuCl and H 2 S···CuCl N. R. Walker et al., J. Chem. Phys., Accepted

6. Molecular transitions CCSD(T) structure prediction Comparison B···MX 300 MHz search range H 2 16 O  109 AgF H 2 16 O  107 AgF H 2 16 O  109 AgF H 2 16 O  107 AgF J’’-J’ = 1 01 ←2 02 J’’-J’ = 1 11 ←2 12 J’’-J’ = 1 01 ←2 02 J’’-J’ = 2 02 ←3 03 J’’-J’ = 1 11 ←2 12, 1 11 ←2 10, 2 12 ←3 13, 2 12 ←3 11

7. H 2 16 O  107 AgF H 2 16 O  109 AgF H 2 18 O  107 AgFH 2 18 O  109 AgF B 0 + C 0 /MHz6147.3147(15)6147.3279(26)5821.3536*5821.2285* B 0 - C 0 /MHz20.8253(10)20.8240(17)18.625518.6248  J / kHz 1.266(44)1.241(75)1.2201.077  JK / kHz 74.31(43)74.70(73)73.0373.30 N6644  r.m.s /kHz2.54.3- - D 2 16 O  107 AgFD 2 16 O  109 AgFHD 16 O  107 AgFHD 16 O  109 AgF B 0 + C 0 / MHz5661.9184*5661.7632*5891.1518*5891.0947*  J / kHz 1.3591.3911.1151.262 N2222  r.m.s /kHz---- *Statistical uncertainties cannot be determined where four parameters are derived from 4 measurements or two parameters derived from two measurements Spectral Constants Spectral fitting carried out in PGOPHER

8. Barrier to inversion

9. ab initio CCSD(T)/VQZ r e Experimental r 0 Ag-F1.9621.985(11) Ag-O2.1822.168(11) ϕ46.0942(1) σ r.m.s. -0.107 As A 0 is not determined and the hydrogens lye off the a-axis geometry of the water subunit assumed to be equal to that of free water Geometry

10. ϕ /ϕ / k  /N m -1 H 2 O···F 2 49(2)3.63(7) H 2 O···Cl 2 43 (3)8.0(1) H 2 O···HF45.524.9 H 2 O···HCl34.7(4)12.9 H 2 O···ClF59(2)14.16(4) Bonding in H 2 O···YX complexes Where Y is a coinage metal or a halogen r H2O-Y /År Y-X /Å For Free MX ϕ /ϕ / k  /N m -1 H 2 16 O··· 107 AgF2.168(15)1.985(11)1.986842(1)57(2) H 2 16 O··· 107 Ag 35 Cl2.198(10)2.273(6)2.28137(2)37 H 2 16 O··· 63 Cu 35 Cl1.91 (10)2.062(6)2.054140(1)58(2) H 2 O ··· ClF H2O ·· F2 S.Cooke et al. J. Chem. Eur., 11, 7 (2001) H 2 O ··· Cl2 J.B.Davey et al., J. Chem. Phys. 114, 6190 (2001) H 2 O ··· HCl Z. Kisiel et al., J. Chem. Phys., 104, 6970 (2000) H 2 O ··· HF Z. Kisiel, A.C. Legon, D.J. Millen, Proc. R. Soc. Lond. A 381, 419, (1982) AgFOkabayashi et al., J. Mol. Spectr., 209, 66 (2001) H 2 O···AgCl and H 2 O···CuCl V. A. Mikhailov et al., J. Chem. Phys., 134, 134305 (2011)

11. Acknowledgements University of Bristol Nick Walker Tony C. Legon David Tew Colin M. Western For development and adaption of PGOPHER for rotational spectroscopy

13. FCl ϕ /ϕ / k  /N m -1 ϕ /ϕ / H 2 O···HX45.524.934.7(4)12.9 H 2 O···AgX42(1)57(2)37(2)37

14. Frequency MHz H 2 18 O  107 AgFH 2 18 O  109 AgFD 2 16 O  107 AgFD 2 16 O  109 AgF 2 1 2 → 1 1 1 ---- 2 0 2 → 1 0 1 11642.6650 b 11642.421611323.7934 b 11323.4821 2 1 1 → 1 10 ---- 3 13 →2 12 17435.5519 a 17435.1916-- 3 03 →2 02 17463.9254 a 17463.565616985.6085 b 16985.1397 3 12 →2 11 17491.4314 b 17491.0659-- Frequency MHz H 2 16 O  107 AgF H 2 16 O  109 AgF HD 16 O  107 AgFHD 16 O  109 AgF 2 1 2 → 1 1 1 12273.4679 b 12273.4975-- 2 0 2 → 1 0 1 12294.5880 b 12294.613411782.2656 b 11782.1490 2 1 1 → 1 10 12315.1178 a 12315.1389-- 3 13 →2 12 18410.1225 b 18410.1622-- 3 03 →2 02 18441.8057 b 18441.846517673.3226 b 17673.1478 3 12 →2 11 18472.5998 b 18472.6385-- a Measurement with isotopically enriched 107 Ag rod b Measurement with natural abundance silver rod. Also observed with isotopically enriched. Less intense signal due to inconsistent 107Ag layer over glass rod at later times of experiment H 2 O ··· AgF molecular transitions

15. ExperimentalM-LM-X r ML (Cl) /r ML (F) OCAgCl2.0162.255 1.026 OCAgF1.9651.944 ArAgCl2.5972.285 1.015 ArAgF2.5581.986 KrAgCl2.6462.277 1.017 KrAgF2.6011.983 XeAgCl2.7112.271 1.018 XeAgF2.6631.98 H2O-AgCl2.1982.272 A 0 GHzB 0 GHzC 0 GHz Search MHz Theoretical H2O-AgF2.14241.981.026357.01823.12493.106912463.6 2.164991.015357.0433.09023.072612325.6 2.160621.017357.03873.09623.078512349.4 2.159081.018357.03663.09923.081512361.4 2.168(11)1.985(11)Exp:12294.0 Ratio of AgCl:AgF bond lengths This has a fairly small range across all ligands Find Ag-F distance across this range Structure prediction by comparison

16. If I 1 and I 2 are the nuclear spin vectors of the H 2 O protons, the Pauli exclusion principle requires that, of the allowed spin states, I 1 + I 2 = 0 must occur in combination with K -1 = 0 rotational levels while the state | I 1 + I 2 |= 1 must occur in combination with k -1 = 1 rotational levels. Hence, no spin-spin interactions involving H 2 O protons can contribute to the extra structure observed in the 2 02 – 1 01 and 3 03 – 2 02 transitions. Or I = 1 state cannot be combined with a wavefunction with K -1 =0 but can with K -1 =1 state. I = 0 can only appear in a K -1 =0 state.