Multicomponent Porphyrin-Based Tetragonal Prismatic Metallacages and their Photophysical Properties.

Multicomponent coordination-driven self-assembly has proved to be a convenient approach to prepare advanced supramolecular coordination complexes (SCCs), especially for those with three-dimensional structures. Herein, we report the preparation of three tetragonal prismatic cages via the self-assembly of Pt(PEt)(OTf), three different linear dipyridyl ligands and porphyrin-based sodium benzoate ligands. Due to the efficient charge separation in the coordination process of Pt(PEt)(OTf) with pyridine and carboxylic acid and the directionality of metal-coordination bonds, these cages were prepared in high isolated yields (more than 90%). The absorption and emission properties as well as the singlet oxygen quantum yields of these cages were also studied, showing their potential applications as contrast agents for bio-imaging and photosensitizers for photodynamic therapy.