EQUILIBRIUM STRUCTURE OF THE SIMPLE SKEW CHAIN MOLECULE
EQUILIBRIUM STRUCTURE OF THE SIMPLE SKEW CHAIN MOLECULE HSOH Oliver Bauma, Jürgen Gaussb, Stephan Schlemmera, Thomas Giesena I. Physikalisches Institut, Universität zu Köln, Germany b Institut für Physikalische Chemie, Universität Mainz, Germany a 61 th International Symposium on Molecular Spectroscopy, Ohio June, 22. 2006
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Outline Motivation Previous works Synthesis Experimental details Results Conclusion International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Structure Motivation H 2 SOn (n=1 -4) internal rotation „missing“ link International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Previous works Structure since 1973 More than 20 theoretical papers deal with structure and/or barrier 1973 -2002 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), 359 -362 International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Previous works Equilibrium Structure of the Simple Skew Chain Molecule HSOH Structure since 1973 More than 20 theoretical papers deal with structure and/or barrier 1973 -2002 Only 2 experimental publications since 2003 5 experimental publications Gas-Phase Detection of HSOH: Synthesis by Flash Vacuum Pyrolysis of Di-tert-butyl Sulfoxide and Rotational-Torsional Spectrum H 34 SOH G. Winnewisser et al. ; Chem. Eur. J. 9 (2003), 5501 -5510 Gas-Phase detection of discharge-generated DSOD M. Behnke et al. ; J. Mol. Spec. 221(1) (2003), 121 -126 Asymmetric rotor analysis of DSOD spectra up to the r. Q 3 branch near 653 GHz S. Brünken et al. ; J. Mol. Struct. 742 (2005), 237 -242 Low-Pressure Pyrolysis of t. Bu 2 SO: Synthesis and IR Spectroscopic Detection of HSOH Beckers et al. ; Chem. Eur. J. 12 (2006), 832 -844 Gas-phase detection of HSOD and empirical equilibrium structure of oxadisulfane O. Baum et al. ; J. Mol. Struct. (2006) (in press) International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Synthesis Equilibrium Structure of the Simple Skew Chain Molecule HSOH ca. 500°C ca. 1200°C HSOH H 34 SOH Di-tert-butylsulfoxide tert-Butylsulfenic acid D 2 O+D 2 S HDO+S 8 RF-discharge Oxadisulfane DSOD HSOD International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Synthesis Equilibrium Structure of the Simple Skew Chain Molecule HSOH ca. 500°C ca. 1200°C HSOH Synthesis H 34 SOH Di-tert-butylsulfoxide tert-Butylsulfenic acid D 2 O+D 2 S HDO+S 8 RF-discharge Oxadisulfane DSOD HSOD International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Synthesis Equilibrium Structure of the Simple Skew Chain Molecule HSOH ca. 500°C ca. 1200°C HSOH H 34 SOH Di-tert-butylsulfoxide tert-Butylsulfenic acid D 2 O+D 2 S HDO+S 8 RF-discharge Oxadisulfane DSOD HSOD International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Experimental details Cologne Terahertz Spectrometer BWOs (ISTOK Corp. , Russia) high power radiation sources (150 -950 GHz with different tubes) down-conversion of the BWOsignal on a harmonic mixer and phase locking of the mixed signal (350 MHz) to a rubidium reference liquid Helium cooled In. Sb hot electron bolometer (QMC Inc, UK) as detector variable frequency modulation of the source and demodulation of the signal by a lock-in amplifier International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Experimental details typical spectrum DSOD ? S 2 O ? SO 2 ? HSOD ? HDO+S 8 (H 2 O: HDO: D 2 O = 1: 2: 1) HSOH ? byproducts ? S 3 ? discrimination of byproducts International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Experimental details HDO+S 8 (H 2 O: HDO: D 2 O = 1: 2: 1) H 2 O+S 8 D 2 O+S 8 discrimination of byproducts International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Experimental details discrimination of byproducts HDO+S 8 (H 2 O: HDO: D 2 O = 1: 2: 1) H 2 O+S 8 D 2 O+S 8 Torsional splitting in HSOH (r. Q 1): 112, 10 111, 10 International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH HSOD c-type transitions r. Q Experimental details 2 -branch b-type transitions International Symposium on Molecular Spectroscopy, Ohio experimental values Oliver Baum (RE 03)
Experimental details Equilibrium Structure of the Simple Skew Chain Molecule HSOH r. Q HSOD 2 -branch experimental calculated J 3, J-2 J 2, J-2 12 11 15 J 3, J-3 J 2, J-1 29 14 10 13 30 12 9 11 8 10 9 7 J=9 J=8 J=10 J=11 J=12 8 31 JKa, Kc International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Results Equilibrium Structure of the Simple Skew Chain Molecule HSOH experimental structure re HSOH experimental DSOD experimental A 0 (MHz) 202069. 05431(134) A 0 (MHz) 106850. 4937(55) B 0 (MHz) 15281. 956620(123) B 0 (MHz) 13865. 38319(173) C 0 (MHz) 14840. 216440(121) C 0 (MHz) 13173. 54491(227) G. Winnewisser et al. (2003) S. Brünken et al. (2005) H 34 SOH experimental HSOD experimental A 0 (MHz) 201739. 7641(129) A 0 (MHz) 159969. 277(303) B 0 (MHz) 15001. 43940(38) B 0 (MHz) 14132. 113(37) C 0 (MHz) 14573. 77816(39) C 0 (MHz) 14020. 600(38) G. Winnewisser et al. (2003) O. Baum et al. (2006) International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Results Equilibrium Structure of the Simple Skew Chain Molecule HSOH „semi-experimental“ structure experimental CCSD(T) / cc-p. VTZ * re HSOH experimental A 0 (MHz) 202069. 05431(134) B 0 (MHz) C 0 (MHz) * J. Gauss et al. DSOD experimental 1431. 9 A 0 (MHz) 106850. 4937(55) 513. 9 15281. 956620(123) 118. 7 B 0 (MHz) 13865. 38319(173) 89. 1 14840. 216440(121) 136. 3 C 0 (MHz) 13173. 54491(227) 106. 8 G. Winnewisser et al. (2003) H 34 SOH experimental A 0 (MHz) 201739. 7641(129) B 0 (MHz) C 0 (MHz) S. Brünken et al. (2005) HSOD experimental 1431. 1 A 0 (MHz) 159969. 277(303) 946. 2 15001. 43940(38) 116. 0 B 0 (MHz) 14132. 113(37) 107. 5 14573. 77816(39) 133. 1 C 0 (MHz) 14020. 600(38) 111. 6 G. Winnewisser et al. (2003) O. Baum et al. (2006) International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
Results Equilibrium Structure of the Simple Skew Chain Molecule HSOH Geometrical parameter Empirical re CCSD(T)/cc-p. VQZ* R(SO) 1. 6616(1) Å 1. 6619 Å R(SH) 1. 3420(2) Å 1. 3414 Å R(OH) a(OSH) a(SOH) t(HSOH) 0. 9606(3) Å 98. 57(5)° 107. 19(3)° 90. 41(11)° 0. 9601 Å 98. 55° 107. 1° 91. 29° * J. Gauss et al. b c a International Symposium on Molecular Spectroscopy, Ohio b Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH International Symposium on Molecular Spectroscopy, Ohio Results Oliver Baum (RE 03)
Equilibrium Structure of the Simple Skew Chain Molecule HSOH Geometrical parameter R(XX) R(SH) R(OH) a(XSH) a(SOH) t(HSOH) X = S, O HSSH J. Behrend et al. (1991) 2. 056 Å 1. 342 Å --97. 9° --90. 3° HSOH O. Baum et al. (2006) 1. 6616(1) Å 1. 3420(2) Å 0. 9606(3) Å 98. 57(5)° 107. 19(3)° 90. 41(11)° International Symposium on Molecular Spectroscopy, Ohio Results HOOH J. -M. Flaud et al. (1989) 1. 456 Å --0. 961 Å --102. 3° 113. 7° Oliver Baum (RE 03)
Conclusion Equilibrium Structure of the Simple Skew Chain Molecule HSOH We derived an empirical equilibrium structure of HSOH aaa The geometrical parameters from ab initio calculations are in very good agreement with the derived data aaa The structure of HSOH fits smoothly into those of its kin molecules HSSH and HOOH HSOH is a molecule with many different traits aaa We found a “simple way” to synthesize HSOH and its deuterated isotopomers Outlook Vibrational dynamics of HSOH HSSOH, HOSOH, … “simple way” International Symposium on Molecular Spectroscopy, Ohio Oliver Baum (RE 03)
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