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 [?I ? 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; ?C-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.

SUBMITTER: Viger-Gravel J 

PROVIDER: S-EPMC4420043 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature