Silicon oxysul!de, OSiS, and seven of its minor isotopic species have been characterized for the !rst time in the gas phase at high spectral resolution by means of Fourier transform microwave spectroscopy. The equilibrium structure of OSiS has been determined from the experimental data using calculated vibration!rotation interaction constants. The structural parameters (rO!Si = 1.5064 Å and rSi!S = 1.9133 Å) are in very good agreement with values from high-level quantum chemical calculations using coupled-cluster techniques together with sophisticated additivity and extrapolation schemes. The bond distances in OSiS are very short in comparison with those in SiO and SiS. This unexpected !nding is explained by the partial charges calculated for OSiS via a natural population analysis. The results suggest that electrostatic e#ects rather than multiple bonding are the key factors in determining bonding in this triatomic molecule. The data presented provide the spectroscopic information needed for radio astronomical searches for OSiS.
S. Thorwirth, L. A. Mueck, J. Gauss, F. Tamassia, V. Lattanzi, M. McCarthy. (2011). Silicon oxysulfide, OSiS: rotational spectrum, quantum-chemical calculations, and equilibrium structure. THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 2, 1228-1231 [10.1021/jz200368x].
Silicon oxysulfide, OSiS: rotational spectrum, quantum-chemical calculations, and equilibrium structure.
TAMASSIA, FILIPPO;
2011
Abstract
Silicon oxysul!de, OSiS, and seven of its minor isotopic species have been characterized for the !rst time in the gas phase at high spectral resolution by means of Fourier transform microwave spectroscopy. The equilibrium structure of OSiS has been determined from the experimental data using calculated vibration!rotation interaction constants. The structural parameters (rO!Si = 1.5064 Å and rSi!S = 1.9133 Å) are in very good agreement with values from high-level quantum chemical calculations using coupled-cluster techniques together with sophisticated additivity and extrapolation schemes. The bond distances in OSiS are very short in comparison with those in SiO and SiS. This unexpected !nding is explained by the partial charges calculated for OSiS via a natural population analysis. The results suggest that electrostatic e#ects rather than multiple bonding are the key factors in determining bonding in this triatomic molecule. The data presented provide the spectroscopic information needed for radio astronomical searches for OSiS.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
