Ab initio studies on vibrational spectra of XSO_2NCO (X=F,Cl):harmonic force fields and frequency assignments  

作　　者：鄢国森 薛英 谢代前 

出　　处：《Science China Chemistry》1998年第1期91-96,共6页中国科学（化学英文版）

基　　金：ProjectsupportedbytheNationalNaturalScienceFoundationofChina (GrantNo .2 96 730 2 9)

摘　　要：The harmonic vibrational force fields and the IR spectrum of XSO 2NCO (X=F,Cl) molecules have been studied using ab initio HF/SCF method with the 6 31G * basis set. The ab initio harmonic force fields are scaled empirically using the scaled quantum mechanical (SQM) method of Pulay. A set of scale factors are optimized by the least squares fitting to the experimental frequencies of FSO 2NCO and then are transferred to ClSO 2NCO to give an a priori prediction of its fundamental frequencies. The average deviations between the theoretical frequencies and the experimental values for FSO 2NCO and ClSO 2NCO are 3 and 5 cm -1 , respectively. The assignments of the fundamentals for these two molecules are also made according to the potential energy distributions and the ab initio IR intensities.The harmonic vibrational force fields and the IR spectrum of XSO 2NCO (X=F,Cl) molecules have been studied using ab initio HF/SCF method with the 6 31G * basis set. The ab initio harmonic force fields are scaled empirically using the scaled quantum mechanical (SQM) method of Pulay. A set of scale factors are optimized by the least squares fitting to the experimental frequencies of FSO 2NCO and then are transferred to ClSO 2NCO to give an a priori prediction of its fundamental frequencies. The average deviations between the theoretical frequencies and the experimental values for FSO 2NCO and ClSO 2NCO are 3 and 5 cm -1 , respectively. The assignments of the fundamentals for these two molecules are also made according to the potential energy distributions and the ab initio IR intensities.

关 键 词：VIBRATIONAL SPECTRA fluorosulfonyl ISOCYANATE chlorosulfonyl ISOCYANATE ab INITIO calculation. 

分 类 号：O657.3[理学—分析化学]