Hybrid Network Formation via Halogen Bonding of the Neutral Bromo-Substituted Organic Molecules with Anionic Metal–Bromide Complexes

2012-08-01T00:00:00Z (GMT) by Sergiy V Rosokha Michael K. Vinakos
X-ray measurements revealed that cocrystallization of various bromocarbons and tetraalkylammonium bromometallate salts lead to the formation of hybrid 3D-networks, which show short intermolecular C–Br···Br–M contacts resulting from halogen bonding between electrophilic organic species and anionic metal–bromide complexes. In particular, halogen bondings of carbon tetrabromide with [MBr4]2– complexes (M = Co, Zn, Cd) produce diamandoid networks in which nodes are occupied interchangeably by tetrahedral organic and inorganic counterparts. (NBu4)2[ZnBr4]·C3Br2F6 structure comprises diamandoid-like network in which nodes are occupied by the tetrahedral [ZnBr4]2– species connected via pairs of bromine substituents in C3Br2F6. Halogen bonding of planar [Pt2Br6]2– complexes with CBr4 and linear [CuBr2] complexes with CHBr3 produces 3D-networks consisting of interconnected ladders. The structural characterization of this series of hybrid networks demonstrates that halogen bonding is strong enough to bring together disparate partners such as neutral aliphatic molecules and ionic salts and is able to accommodate a variety of geometries of the interacting species. Comparison of the intermolecular contact locations with the surface electrostatic potentials and molecular orbital shapes of the bromometallates suggests the importance of the covalent component in halogen bonding.