X-Ray Structure Determinations of Bromo- and/or Bromomethylsubstituted Benzenes: C–H···Br, C–Br···Br, and C–Br···π Interactions

Abstract

The structures of seven benzene derivatives [1,2,3-tri(bromomethyl)benzene, (1); 3,5- di(bromomethyl)bromobenzene, (2); 2,5-di(bromomethyl)bromobenzene, (3); 4-(bromomethyl)-2,5- dibromotoluene, (4); 4-(bromomethyl)bromobenzene, (5); 2,3-di(bromomethyl)bromobenzene, (6) and (bromomethyl)-p-dibromobenzene, (7)] with bromo and bromomethyl (and in one case methyl) substituents are presented and analysed in terms of Br···Br interactions up to 4.0 A° , supported by hydrogen bonds H···Br. Some interactions of the type Br···π and π···π are encountered and play a subordinate role in the packing. Despite the close chemical similarity of the compounds, some of which are isomers with permuted substituent positions, the packing motifs are highly variable. Compounds 2-5 are based on layer structures with Brn (n=3, 4) and/or mixed Br/C rings. Compounds 1, 6 and 7 display three-dimensional packings of differing complexity, but with interpretable substructures; 1 can be analysed in terms of ribbons of linked Br3 and Br4 rings; 6 displays chains of linked Br3 triangles; 7 consists of ribbons of linked Br4 quadrilaterals.