title: Crystal structure of 4'-bromo-2,3,5,6-tetra-fluoro-biphenyl-4-carbo-nitrile.
abstract: The title compound, C13H4BrF4N, synthesized from 1,4'-bromo-iodo-benzene and 4-bromo-2,3,5,6-tetra-fluoro-benzo-nitrile in a coupling reaction was found to crystallize in the ortho-rhom-bic space group P212121. The two phenyl rings are rotated with respect to each other by 40.6 (6)°. The mol-ecules inter-act via aryl-perfluoroaryl stacking [3.796 (2) and 3.773 (2) Å], resulting in inter-molecular chains along the a-axis direction. C-H⋯F contacts of about 2.45 Å connect these chains. In contrast to the structure of the parent compound 4'-bromo-biphenyl-4-carbo-nitrile, CN⋯Br contacts that could have given rise to a linear arrangement of the biphenyl mol-ecules desirable for non-linear optical (NLO) materials are not observed in the packing. Instead, several Br⋯F [3.2405 (17) and 3.2777 (18) Å] and F⋯F [2.894 (2) Å] contacts of side-on type II form an inter-molecular network of zigzag chains. The crystal studied was refined as an inversion twin.
authors.affiliation: Institut für Organische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, D-09596 Freiberg/Sachsen, Germany.
authors.forename: Ricarda
authors.initials: R
authors.lastname: Heckel
authors.affiliation: Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, CH-3012 Berne, Switzerland.
authors.forename: Jürg
authors.initials: J
authors.lastname: Hulliger
authors.affiliation: Institut für Organische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, D-09596 Freiberg/Sachsen, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Schwarzer
authors.affiliation: Institut für Organische Chemie, TU Bergakademie Freiberg, Leipziger Strasse 29, D-09596 Freiberg/Sachsen, Germany.
authors.forename: Edwin
authors.initials: E
authors.lastname: Weber
keywords: biphen­yl; bromo–cyano substitution; crystal structure; halogen inter­actions; tetra­fluoro substitution; π–πF stacking