A Molecular Transformer: A π‐Conjugated Macrocycle as an Adaptable Host
Junting Wang, Yang‐Yang Ju, Kam‐Hung Low, Yuan‐Zhi Tan, Junzhi Liu
Abstract
Abstract Here, we report a facile method to synthesize a series of macrocycles with different conformations. The planar macrocycle dimer ( 1 ), twisted macrocycle trimer ( 2 ) and “figure‐eight” tetramer ( 3 ) are clearly elucidated by X‐ray single‐crystal analysis, in which the electron‐rich phenanthrene units offer the possibility of supramolecular assembly. As expected, in the solid state, 1 and 3 assemble into a columnar stack and an interlocking dimer, respectively, via π–π interactions between the phenanthrene units. Compared to the rigid conformation of dimer 1 , the structure of tetramer 3 is more flexible due to its enlarged ring size. 3 can deform from a figure‐eight into a boat‐shaped geometry to host a planar electron‐deficient guest using its electron‐rich phenanthrene units. When assembled with spherical electron‐deficient C 60 , interestingly, 3 further undergoes a conformational transformation from a figure‐eight to a belt shape in order to host C 60 . These supramolecular assembly behaviors of 3 demonstrate that it is an adaptable macrocyclic host for both planar molecules and fullerenes.