Structural Switching of a Distorted Trigonal Metal-Organic Cage to a Tetragonal Cage and Singlet Oxygen Mediated Oxidations.

Construction of metal-organic cages with unique architecture and guest binding abilities is highly desirable. Herein, we report the synthesis of a distorted trigonal cage 1 from a twisted tetratopic ligand (L) and a Pd(II) acceptor. Surprisingly, 1 exhibited a complete structural reorganization of its building units in presence of C70 and C60 to form guest-encapsulated tetragonal cages, (C70)2@2 and (C60)2@2, respectively. These guest-bound cages were found to be potential 1O2 generators and the former effectively catalyzed two different varieties of 1O2-mediated oxidation reactions.