Tuning the Properties of Metal-Organic Cages through Platinum Nanoparticle Encapsulation

摘要

Metal-organic cages (MOCs) are promising candidates for drug deliveries, catalysis, and host-guest systems. In addition, their own finite cavities can control to the sizes and shapes of metal nanoparticles (MNPs), leading to promote their catalytic performance. Herein, we used half-sandwich rhodium moieties with pyridyl ligands through coordination-driven self-assembly strategy and bridged-unit (tpphz)-mediated host-guest complex formation in concert to produce a sufficient cavity with about 2.0 nm of size that facilitate to prepare controllably sizes and shapes of MNPs. Specifically, a metal-organic cage 1, containing robust ligands (tpeb) and bridged units, has been successfully synthesized and fully characterized by several spectroscopic techniques. Its final structure was unambiguously confirmed by single-crystal X-ray diffraction (SCXRD). The pyridyl ligand units of 1 underwent noncovalent complexation with platinum nanoparticles to yield a Pt-NPs@1 under UV-visible irradiation of K2PtCl6. Moreover, UV and CV were carried out to determine the redox properties of 1 and Pt-NPs@1, finding that Pt-NPs@1 has a good redox property. Therefore, the supramolecular composites were used as catalysis for degradation of dye stuffs in aqueous solution, exhibiting good selectivity and activity.