Zinc‐[7]helicenocyanine and Its Discrete π‐Stacked Homochiral Dimer

In this communication, we demonstrate a novel approach to prepare a discrete dimer of chiral phthalocyanine (Pc) by exploiting the flexible molecular geometry of helicenes, which enables structural interlocking and strong aggregation tendency of Pcs. Synthesized [7]helicene‐Pc hybrid molecular structure, zinc‐[7]helicenocyanine (Zn‐7HPc), exclusively forms a stable dimeric pair consisting of two homochiral molecules. The dimerization constants were estimated to be as high as 8.96×10(6) M(−1) and 3.42×10(7) M(−1) in THF and DMSO, respectively, indicating remarkable stability of dimer. In addition, Zn‐7HPc exhibited chiral self‐sorting behavior, which resulted in preferential formation of a homochiral dimer also in the racemic sample. Two phthalocyanine subunits in the dimeric form strongly communicate with each other as revealed by a large comproportionation constant and observation of an IV‐CT band for the thermodynamically stable mixed‐valence state.