Crystal structures of the 2:2 complex of 1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) and tetra-butyl-ammonium chloride or bromide.

ABSTRACT: The title compounds, tetra-butyl-ammonium chloride-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C₁₆H₃₆N⁺·Cl^-·C₂₂H₂₂N₄O₂ or [(n-Bu₄N⁺·Cl^-)(C₂₂H₂₂N₄O₂)] (I) and tetra-butyl-ammonium bromide-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C₁₆H₃₆N⁺·Br^-·C₂₂H₂₂N₄O₂ or [(n-Bu₄N⁺·Br^-)(C₂₂H₂₂N₄O₂)] (II), both comprise a tetra-butyl-ammonium cation, a halide anion and an ortho-phenyl-ene bis-urea mol-ecule. Each halide ion shows four N-H?X (X = Cl or Br) inter-actions with two urea receptor sites of different bis-urea moieties. A crystallographic inversion centre leads to the formation of a 2:2 arrangement of two halide anions and two bis-urea mol-ecules. In the crystals, the dihedral angle between the two urea groups of the bis-urea mol-ecule in (I) [defined by the four N atoms, 165.4?(2)°] is slightly smaller than that in (II) [167.4?(2)°], which is probably due to the smaller ionic radius of chloride compared to bromide.

SUBMITTER: Huang C 

PROVIDER: S-EPMC5588570 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature