An Ab Initio Study of Conformational Energies in Dioxo-, Trioxo-, and Tetroxo-Dithianes |
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| Authors: | Issa Yavari Rahebeh Amiri Mina Haghdadi |
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| Affiliation: | 1. Chemistry Department, Science and Research Campus , Islamic Azad University , Ponak, Tehran, Iran;2. Chemistry Department , Tarbiat Modarres University , Tehran, Iran;3. Chemistry Department , Islamic Azad University, Tehran Central Branch , Tehran, Iran;4. Chemistry Department , Islamic Azad University , Amol, Mazandaran, Iran |
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| Abstract: | Ab initio Hartree–Fock calculations at the HF/6-31G* level of theory for geometry optimization and the MP2/6-31G*//HF/6-31G* and B3LYP/6-311G(2df,p)//HF/6-31G* levels for a single point total energy calculation are reported for the important energy-minimum conformations of 1,1-dioxo-thiane (2), 1,1-dioxo-1,2-dithiane (3), 1,1-dioxo-1,3-dithiane (4), 1,1-dioxo-1,4-dithiane (5), 1,1,2-trioxo-1,2-dithiane (6), 1,1,3-trioxo-1,3-dithiane (7), 1,1,4-trioxo-1,4-dithiane (8), 1,1,2,2-tetroxo-1,2-dithiane (9), 1,1,3,3-tetroxo-1,3-dithiane (10), and 1,1,4,4-tetroxo-1,4-dithiane (11). According to the MP2/6-31G*//HF/6-31G* calculations, compound 5 is more stable than 3 and 4 by 7.8 and 8.9 kJ mol?1, respectively. The axial geometries of 6 and 8 are more stable than the equatorial forms by 21.4 and 19.1 kJ mol?1, respectively, but the equatorial form of 7 is 4.1 kJ mol?1 more stable than the axial geometry. Compound 11 is more stable than 9 and 10 by 49.3 and 31.0 kJ mol?1, respectively. |
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| Keywords: | Conformational energies cyclic sulfoxides dioxo-dithiane stereochemistry |
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