“Conformational” Solvatochromism: Spatial Discrimination of Nonpolar Solvents by Using a Supramolecular Box of a π‐Conjugated Zinc Bisporphyrin Rotamer

Boxing clever: A cyclic tetramer of the dialkynylene-bridged zinc bisporphyrin rotamer [ZnP()2] shows a unique solvatochromic response to nonpolar solvents with equally low dielectric constants (2.23–2.57). This solvatochromism originates from the π conjugation of [ZnP ()2]. The tetramer [{ZnP()2}4] can discriminate spectroscopically benzene from CCl4 (see picture) and even the regioisomers of xylene.