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Divinylketone: Conformational preferences. Molecular geometry and vibrational force field in the ground state
Author(s) -
Skancke Per N.
Publication year - 1983
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.540040204
Subject(s) - saddle point , conformational isomerism , ground state , ab initio , force field (fiction) , potential energy surface , chemistry , field (mathematics) , molecular orbital , maxima and minima , homogeneous space , molecule , molecular physics , geometry , computational chemistry , energy minimization , potential energy , atomic physics , physics , quantum mechanics , mathematics , mathematical analysis , organic chemistry , pure mathematics
The conformational preferences of the molecule 1,4‐pentadien‐3‐one (divinylketone) have been studied by ab initio molecular orbital calculations and discussed in terms of interaction between molecular fragments. The calculations predict a molecular ground state having a fully coplanar s ‐cis, s ‐cis conformation. In addition, we find three other structures that represent local minima on the energy surface. These are a fully coplanar s ‐cis, s ‐trans form, and two nonplanar s ‐trans, s ‐trans forms having symmetries C 2 and C 1 h , respectively. The energies of these forms relative to the ground state are 7.5, 19.2, and 35.9 kJ/mol, respectively. The coplanar s ‐trans, s ‐trans form represents a saddle point on the energy surface. All conformers and the saddle point have been completely geometry optimized by the gradient technique. For the ground state a complete in‐plane harmonic force field has been evaluated.