Hybrid network formation via halogen bonding of the neutral bromo-substituted organic molecules with anionic metal-bromide complexes

摘要

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-BrBr-M contacts resulting from halogen bonding between electrophilic organic species and anionic metal-bromide complexes. In particular, halogen bondings of carbon tetrabromide with [MBr _4] ~(2-) complexes (M = Co, Zn, Cd) produce diamandoid networks in which nodes are occupied interchangeably by tetrahedral organic and inorganic counterparts. (NBu _4) _2[ZnBr _4]C _3Br _2F _6 structure comprises diamandoid-like network in which nodes are occupied by the tetrahedral [ZnBr _4] ~(2- species connected via pairs of bromine substituents in C _3Br _2F _6. Halogen bonding of planar [Pt _2Br _6] ~(2-)) complexes with CBr _4 and linear [CuBr _2] ~- complexes with CHBr _3 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.