Ab Initio Study of Conformational Properties of Heteroatom-Containing 1,2-Bisketene Analogues |
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| Authors: | S. Zahra Sayyed-Alangi Mohammad T. Baei Javad Nejati Ali Varasteh Moradi |
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| Affiliation: | 1. Department of Chemistry, Azadshahr Branch , Islamic Azad University , Azadshahr , Golestan , Iran;2. Young Researchers Club, Aliabad Katool Branch , Islamic Azad University , Aliabad Katool , Golestan , Iran;3. Department of Chemistry , Gorgan Branch, Islamic Azad University , Gorgan , Golestan , Iran |
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| Abstract: | Abstract Minimum-energy and transition-state geometries of 4-oxobuta-1,3-diene-1-thione, buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, 4-selenoxobuta-1,3-diene-1-one, and buta-1,3-diene-1,4-diselenone were calculated using HF, B3LYP, and MP2 levels of theory and 6–31 + G* basis set by rotation around the related ?C?C? single bonds. In all of the above-mentioned molecules, the s-trans conformation was obtained as the most stable conformer with the 180° dihedral angle. In buta-1,3-diene-1,4-dithione, 4-selenoxobuta-1,3-diene-1-thione, and buta-1,3-diene-1,4-diselenone, the s-cis form of these compounds corresponded to the other energy-minimum geometry. Their skew geometries, with torsional angles approximately 100°, were a transition state for conformational interconversion between the two global minima forms. In 4-oxobuta-1,3-diene-1-thione and 4-selenoxobuta-1,3-diene-1-one, geometries with the C?C?C?C dihedral angles about 51 and 43° (respectively) were attributed to the second energy-minimum geometry. Transition-state structures from both molecules were found in the torsional angles at about 0 and 100°. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT |
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| Keywords: | Bisketenes bisselenoketenes bisthioketenes conformational analysis |
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