title: Crystal structure of tetra-butyl-ammonium bromide-1,2-di-iodo-3,4,5,6-tetra-fluoro-benzene-di-chloro-methane (2/2/1).
abstract: The crystallization of a 1:1 molar solution of 1,2-di-iodo-3,4,5,6-tetra-fluoro-benzene (o-DITFB) and tetra-butyl-ammonium bromide (n-Bu4NBr) from di-chloro-methane yielded pure white crystals of a halogen-bonded compound, C16H36N(+)·Br(-)·C6F4I2·0.5CH2Cl2 or [(n-Bu4NBr)(o-DITFB)]·0.5CH2Cl2. The compound may be described as a quaternary system and may be classified as a salt-cocrystal solvate. The asymmetric unit contains one mol-ecule of solvent, two o-DITFB mol-ecules, two cations (n-Bu4N(+)) and two crystallographically distinct bromide ions [θI ⋯ Br- ⋯ I = 144.18 (1) and 135.35 (1)°]. The bromide ion is a bidentate halogen-bond acceptor which inter-acts with two covalently bonded iodines (i.e. halogen-bond donors), resulting in a one-dimensional polymeric zigzag chain network approximately along the a axis. The observed short contacts and angles are characteristic of the non-covalent inter-action [d C-I⋯Br = 3.1593 (4)-3.2590 (5) Å; θC-I⋯Br = 174.89 (7) and 178.16 (7)°]. It is noted that iodine acts as both a halogen-bond donor and a weak CH hydrogen-bond acceptor, while the bromide ions act as acceptors for weak CH hydrogen bonds and halogen bonds.
authors.affiliation: Department of Chemistry, University of Ottawa, D'Iorio Hall, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Viger-Gravel
authors.affiliation: Department of Chemistry, University of Ottawa, D'Iorio Hall, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: Ilia
authors.initials: I
authors.lastname: Korobkov
authors.affiliation: Department of Chemistry, University of Ottawa, D'Iorio Hall, 10 Marie Curie Private, Ottawa, Ontario, K1N 6N5, Canada.
authors.forename: David L
authors.initials: DL
authors.lastname: Bryce
keywords: crystal structure; halogen bonds; noncovalent inter­action; short contacts