M. Sugino, H. Takeuchi, T. Egawa
May 31, 1991
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Influential Citations
15
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract The molecular structure and conformation of ethyl acetate, , have been determined by gas electron diffraction. The result of ab initio calculations reported by Manning was used as an aid to the analysis. The torsional vibrations of C 3 (acetoxy) methyl and ethyl groups were treated as large amplitude motions and the potential function was obtained for the ethyl torsion. The O 2 C 1 O 4 C 5 dihedral angle was fixed at O° and the C 6 methyl group was assumed to take the staggered conformation against the C 5 C 6 bond. Two stable conformers, trans and gauche, are found to have the dihedral angles C 1 O 4 C 5 C 6 , of 180° and 79°, respectively. The abundance of the trans conformer is derived to be 38 ± 7%. The structural parameters of the trans conformer are determined as follows (the numbers in parentheses represent estimated limits of error): r g (C 3 H 7 = 1.105(3)A, r g (C 1 O 2 ) = 1.203(2)A, r g (C 1 C 3 = 1.508(2) A, r g (C 1 O 4 ) = 1.345(3) A r g (O 4 C 5 ) = 1.448(3) A, r g (C 5 C 6 ) = 1.515(2) A, ∠ α O 2 C 1 C 3 = 124.1(10)°, ∠ α O 2 C 1 O 4 =124.0(3)°, ∠ α C 1 O 4 C 5 = 115.7(5)°, ∠O 4 C 5 C 6 =108.2(11)°, ∠ α C 1 C 3 H = 107.7(13)° and ∠ α C 5 C 6 H = 108.1(13)°.