Crystal structures of methyl 3,5-dibromo-4-cyanobenzoate and methyl 3,5-dibromo-4-isocyanobenzoate

Abstract

The title crystals, C9H5Br2NO2, are the first reported 2,6-dihalophenyl cyanide–isocyanide pair that have neither three- nor two-dimensional isomorphism. Both crystals contain contacts between the carbonyl O atom and a Br atom. In the crystal of the cyanide,R22(10) inversion dimers form based on C[triple-bond]N...Br contacts, a common packing feature in this series of crystals. In the isocyanide, the corresponding N[triple-bond]C...Br contacts are not observed. Instead, the isocyano C atom forms contacts with the methoxy C atom. RNC was refined as a two-component pseudo-merohedral twin.