λ 5-Phospha[7]helicenes: Synthesis, properties, and columnar aggregation with one-way chirality

Abstract

One-way street: A new family of λ 5-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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.