1,3-Dibromo-2,4,6-trinitrobenzene (DBTNB). Crystal engineering and perfect polar alignment of two-dimensional hyperpolarizable chromophores

1,3-Dibromo-2,4,6-trinitrobenzene (DBTNB), a two-dimensional charge transfer hyperpolarisable chromophore, crystallises in the non-centrosymmetric space group C2 in perfect polar order leading to an intense powder SHG signal at 1.06 mum.