Multiaddressable molecular rectangles with reversible host-guest interactions: modulation of pH-controlled guest...

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Platinum(II) complexes are investigated for therapeutic potential.
• Host-guest chemistry offers precise molecular recognition and encapsulation.
• Molecular rectangles provide defined cavities for guest molecules.

Purpose of the Study:

• Synthesize multiaddressable platinum(II) molecular rectangles with tunable properties.
• Investigate host-guest interactions with various metal complexes, including potential anticancer agents.
• Explore pH-responsive functionalities for controlled drug delivery applications.

Main Methods:

• Synthesis of platinum(II) molecular rectangles using U-shaped diplatinum(II) terpyridine and bis-alkynyl ligands.
• Host-guest association studies with square planar and low-dimensional metal complexes.
• Spectroscopic analysis (2D NMR) and van't Hoff analysis for binding thermodynamics.
• Computational studies to support experimental findings.

Main Results:

• Achieved excellent guest confinement and selectivity using the rectangular architecture.
• Demonstrated pH-responsive reversible guest release and capture.
• Observed spectroscopic changes influenced by metal-metal, π-π, and electrostatic interactions.
• Determined binding modes and thermodynamic parameters of host-guest complexes.

Conclusions:

• Multiaddressable platinum(II) molecular rectangles exhibit high selectivity for guest encapsulation.
• pH-responsive systems show promise for controlled therapeutics delivery.
• Intermolecular interactions significantly influence host-guest complex stability and recognition.