Capturing a Square Planar Gold(III) Complex Inside a Platinum Nanocage: A Combined Experimental and Theoretical Study

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Platinum coordination cages (Pt₂L₄) are less explored than their palladium analogs.
• Coordination cages are investigated for their potential in host-guest chemistry and molecular recognition.
• Encapsulation of metal complexes within cages is a challenging but valuable area of research.

Purpose of the Study:

• To synthesize novel platinum coordination cages (Pt₂L₄) using a new procedure.
• To investigate the host-guest capabilities of the Pt₂L₄ cage, specifically for encapsulating metal complexes.
• To compare the encapsulation efficiency of the platinum cage with its palladium counterpart.

Main Methods:

• Novel synthetic procedure for Pt₂L₄ coordination cages.
• Host-guest encapsulation experiments using an Au(III) metal complex ([Au(bdt)₂]^-).
• Characterization using Nuclear Magnetic Resonance (NMR) spectroscopy and X-ray crystallography.
• Density Functional Theory (DFT) computational studies to analyze host-guest interactions.

Main Results:

• Successfully synthesized Pt₂L₄ coordination cages with a suitable cavity for guest encapsulation.
• Achieved the encapsulation of the [Au(bdt)₂]^- gold(III) complex within the platinum cage.
• The analogous palladium cage failed to encapsulate the gold complex, highlighting the unique properties of the platinum cage.
• This represents a rare instance of a metal complex with thio-ligands being encapsulated in a coordination cage.

Conclusions:

• The platinum coordination cage (Pt₂L₄) demonstrates superior host-guest capabilities compared to its palladium analog.
• The study highlights the importance of the metal center and the robustness of platinum cages in host-guest chemistry.
• This work encourages further research into platinum-based coordination cages for advanced applications.