λ⁵‐Phospha[7]helicenes: Synthesis, Properties, and Columnar Aggregation with One‐Way Chirality

One-way street: A new family of λ5-phospha[7]helicenes which form one-dimensional columnar stacks in the solid state were synthesized (see scheme). Neighboring stacks have opposite dipole directions and, in the case of the racemic phosphole sulfide based helicene, columns with a given dipole direction consist of one enantiomer, whereas columns with the opposite dipole direction consist of the other enantiomer.