Ab Initio Studies on 5-Bromo-10-Oxa-3-Thiatricyclo[5.2.1.01,5]-Dec-8-Ene 3,3-Dioxide
Hakan Arslan1,* and Aydin Demircan2
1 Department of Chemistry, Faculty of Arts and Science, Mersin
University, 33343-Mersin, Turkey
2 Department of Chemistry, Faculty of Liberal Arts and Science, University of Nigde, 51100-Nigde, Turkey
5-Bromo-10-oxa-3-thiatricyclo[5.2.1.01,5]-dec-8-ene 3,3-dioxide (BOTCDO) was synthesized from the reaction between 2-(2-bromoallylsulfanylmethyl)-furan and m-chloroperbenzoic acid in dichloromethane. The molecular structure and vibrational frequencies of BOTCDO in the ground state have been investigated with ab initio (HF) and density functional theory methods (B3LYP, B3PW91 and MPW1PW91) implementing the standard 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT methods show the best agreement with the experimental data. Comparison of the observed fundamental vibrational frequencies of title compound and calculated results by HF and DFT methods indicate that MPW1PW91 is superior to the scaled HF approach for molecular problems. Optimal uniform scaling factors calculated for the title compound are 0.8920, 0.9553, 0.9518 and 0.9452 for HF, B3LYP, B3PW91 and MPW1PW91 methods, respectively.
Keywords: HF; DFT; FT-IR spectrum; quantum chemical calculations; furans; sulfoxide.