caa a22 4500 469072423 CHVBK 20180323132925.0 cr unu---uuuuu 170328e19920401xx s 000 0 eng 10.1007/BF00671807 doi (NATIONALLICENCE)springer-10.1007/BF00671807 Relative Stability of cis and trans conformers of 2- and 3-fluorostyrene: An ab initio SCF-MO study [Elektronische Daten] [J. Teixeira-Dias, P. Ribeiro-Claro] Ab initio SCF-MO calculations, mainly at the 6-31G F* level with 3-21G F* fully optimized geometries, were performed for 2- and 3-fluorostyrene in different comformations. Structures and conformational preferences of these molecules are compared with available data and discussed. It was found that the 2-fluorostyrene molecule has acis-trans energy difference of ca. 2.4 kJ mol−1, showing a small barrier to planarity of 0.26 kJ mol−1 in thetrans form. While the reduced stability of thecis form is mainly ascribed to a repulsive F ... vinyl group interaction, the partial loss of resonance stabilization between the ring and the vinyl group in the trans form and the H6 ... Hc repulsive interaction in this form are taken to explain the local maximum atθ=180‡. In the 3-fluorostyrene molecule, thecis form is favored over thetrans by ca. 0.5 kJ mol−1. An appreciable asymmetry of charge distribution found for thetrans form is assumed to slightly overweigh the difference in nuclear repulsion energy favorable to this conformation, thus explaining the observed relative stability. Plenum Publishing Corporation, 1992 Teixeira-Dias J. University Chemistry Department, P-3049, Coimbra, Portugal aut Ribeiro-Claro P. University Chemistry Department, P-3049, Coimbra, Portugal aut Structural Chemistry Kluwer Academic Publishers 3/2(1992-04-01), 95-101 1040-0400 3:2<95 1992 3 11224 https://doi.org/10.1007/BF00671807 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00671807 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Teixeira-Dias J. University Chemistry Department, P-3049, Coimbra, Portugal aut NATIONALLICENCE 700 1- Ribeiro-Claro P. University Chemistry Department, P-3049, Coimbra, Portugal aut NATIONALLICENCE 773 0- Structural Chemistry Kluwer Academic Publishers 3/2(1992-04-01), 95-101 1040-0400 3:2<95 1992 3 11224 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer