Anthracene-induced formation of highly twisted metallacycle and its crystal structure and tunable assembly behaviors

Polycyclic aromatic hydrocarbons (PAHs) continue to attract increasing interest with respect to their applications as luminescent materials. The ordered structure of the metal-organic complex facilitates the selective integration of PAHs that can be tuned to function cooperatively. Here, a unique highly twisted anthracene-based organoplatinum metallacycle was prepared via coordination-driven self-assembly. Single-crystal X-ray diffraction analysis revealed that the metallacycle was twisted through the cooperation of strong π···π stacking interactions and steric hindrance between two anthracene-based ligands. Notably, the intramolecular twist and aggregation behavior introduced restrictions to the conformational change of anthracenes, which resulted in increased emission intensity of the metallacycle in solution. The emission behaviors and suprastructures based on the highly twisted metallacycle can be modulated by the introduction of different solvents. This study demonstrates that this metallacycle with highly twisted structure is a promising candidate for sensing and bioimaging applications.