E QUILIBRIUM S TRUCTURE OF THE S IMPLE S KEW C HAIN M OLECULE HSOH 61 th International Symposium on Molecular Spectroscopy, Ohio June, Oliver Baum a, Jürgen Gauss b, Stephan Schlemmer a, Thomas Giesen a a I. Physikalisches Institut, Universität zu Köln, Germany b Institut für Physikalische Chemie, Universität Mainz, Germany

Outline Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Previous works Results Synthesis Experimental details Motivation Conclusion

Equilibrium Structure of the Simple Skew Chain Molecule HSOH Motivation Oliver Baum (RE03) International Symposium on Molecular Spectroscopy, Ohio H 2 SO n (n=1-4) Structure internal rotation „missing“ link

Equilibrium Structure of the Simple Skew Chain Molecule HSOH Previous works Oliver Baum (RE03) International Symposium on Molecular Spectroscopy, Ohio Structure since 1973 More than 20 theoretical papers deal with structure and/or barrier Only 2 experimental publications Matrix reactions of oxygen atoms with H 2 S molecules R. R. Smardzewski and M.C. Lin; J. Chem. Phys. 66 (1977), 3197 Experimental evidence for the gas phase existence of HSOH (hydrogen thioperoxide) and SOH 2 (thiooxonium ylide) M. Iraqi and H. Schwarz; Chem. Phys. Lett. 221 (1994),

Equilibrium Structure of the Simple Skew Chain Molecule HSOH Previous works Oliver Baum (RE03) International Symposium on Molecular Spectroscopy, Ohio Structure since since experimental publications Gas-Phase Detection of HSOH: Synthesis by Flash Vacuum Pyrolysis of Di-tert-butyl Sulfoxide and Rotational-Torsional Spectrum G. Winnewisser et al.; Chem. Eur. J. 9 (2003), Gas-Phase detection of discharge-generated DSOD M. Behnke et al.; J. Mol. Spec. 221(1) (2003), Asymmetric rotor analysis of DSOD spectra up to the r Q 3 branch near 653GHz S. Brünken et al.; J. Mol. Struct. 742 (2005), Gas-phase detection of HSOD and empirical equilibrium structure of oxadisulfane O. Baum et al.; J. Mol. Struct. (2006) (in press) Low-Pressure Pyrolysis of tBu 2 SO: Synthesis and IR Spectroscopic Detection of HSOH Beckers et al.; Chem. Eur. J. 12 (2006), H 34 SOH More than 20 theoretical papers deal with structure and/or barrier Only 2 experimental publications

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Di-tert-butylsulfoxide ca. 500°C tert-Butylsulfenic acid ca. 1200°C Oxadisulfane HSOH H 34 SOH D 2 O+D 2 SDSOD RF-discharge HDO+S 8 HSOD RF-discharge Synthesis

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Synthesis Di-tert-butylsulfoxide ca. 500°C tert-Butylsulfenic acid ca. 1200°C Oxadisulfane HSOH H 34 SOH D 2 O+D 2 SDSOD RF-discharge HDO+S 8 HSOD RF-discharge

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Synthesis Di-tert-butylsulfoxide ca. 500°C tert-Butylsulfenic acid ca. 1200°C Oxadisulfane HSOH H 34 SOH D 2 O+D 2 SDSOD RF-discharge HDO+S 8 HSOD RF-discharge

Cologne Terahertz Spectrometer Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio BWOs (ISTOK Corp., Russia) high power radiation sources ( GHz with different tubes) down-conversion of the BWO- signal on a harmonic mixer and phase locking of the mixed signal (350 MHz) to a rubidium reference variable frequency modulation of the source and demodulation of the signal by a lock-in amplifier liquid Helium cooled InSb hot electron bolometer (QMC Inc, UK) as detector Experimental details

HDO+S 8 (H 2 O:HDO:D 2 O = 1:2:1) HDO+S 8 Experimental details Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio typical spectrum byproducts ? HSOH ? HSOD ? DSOD ? SO 2 ? S 2 O ? S 3 ? discrimination of byproducts

H 2 O+S 8 HDO+S 8 (H 2 O:HDO:D 2 O = 1:2:1) D 2 O+S 8 HDO+S 8 Experimental details Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio discrimination of byproducts

HDO+S 8 (H 2 O:HDO:D 2 O = 1:2:1) HDO+S 8 H 2 O+S 8 D 2 O+S 8 Torsional splitting in HSOH ( r Q 1 ): 11 2,10  11 1,10 Experimental details Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio discrimination of byproducts

c-type transitionsb-type transitions HSOD r Q 2 -branch experimental values Experimental details Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio

experimental calculated J 3,J-2  J 2,J-2 HSOD r Q 2 -branch J= J=9 10 J=10 11 J=11 12 J= J 3,J-3  J 2,J-1 J K a, K c Experimental details Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio

experimental structure HSOHexperimental A 0 (MHz) (134) B 0 (MHz) (123) C 0 (MHz) (121) G. Winnewisser et al. (2003) DSODexperimental A 0 (MHz) (55) B 0 (MHz) (173) C 0 (MHz) (227) S. Brünken et al. (2005) HSODexperimental A 0 (MHz) (303) B 0 (MHz) (37) C 0 (MHz) (38) O. Baum et al. (2006) H 34 SOHexperimental A 0 (MHz) (129) B 0 (MHz) (38) C 0 (MHz) (39) G. Winnewisser et al. (2003) Results Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio experimental structure rere

HSOHexperimental A 0 (MHz) (134) B 0 (MHz) (123)118.7 C 0 (MHz) (121)136.3 G. Winnewisser et al. (2003) DSODexperimental A 0 (MHz) (55)513.9 B 0 (MHz) (173)89.1 C 0 (MHz) (227)106.8 S. Brünken et al. (2005) HSODexperimental A 0 (MHz) (303)946.2 B 0 (MHz) (37)107.5 C 0 (MHz) (38)111.6 O. Baum et al. (2006) H 34 SOHexperimental A 0 (MHz) (129) B 0 (MHz) (38)116.0 C 0 (MHz) (39)133.1 G. Winnewisser et al. (2003) Results Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio „semi-experimental“ structure rere experimental CCSD(T) / cc-pVTZ * J. Gauss et al. *

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Results b ab cc a Geometrical parameter Empirical r e CCSD(T)/cc-pVQZ R(SO)1.6616(1) Å Å R(SH)1.3420(2) Å Å R(OH)  (OSH)  (SOH)  (HSOH) (3) Å 98.57(5)° (3)° 90.41(11)° Å 98.55° 107.1° 91.29° * J. Gauss et al. *

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Results

Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Geometrical parameter HSSH J. Behrend et al. (1991) HSOH O. Baum et al. (2006) HOOH J.-M. Flaud et al. (1989) R(XX)2.056 Å1.6616(1) Å1.456 Å R(SH)1.342 Å1.3420(2) Å--- R(OH)  (XSH)  (SOH)  (HSOH) ° ° (3) Å 98.57(5)° (3)° 90.41(11)° Å ° 113.7° Results X = S,O

aa a Conclusion aa a We found a “simple way” to synthesize HSOH and its deuterated isotopomers aa a We derived an empirical equilibrium structure of HSOH HSOH is a molecule with many different traits Vibrational dynamics of HSOH Outlook Oliver Baum (RE03) Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio The geometrical parameters from ab initio calculations are in very good agreement with the derived data The structure of HSOH fits smoothly into those of its kin molecules HSSH and HOOH HSSOH, HOSOH, …  “simple way”