Ring-opening polymerization of cyclic esters by phenoxy-thioether complexes derived from biocompatible metals.

Area of Science:

• Organometallic Chemistry
• Polymer Chemistry
• Catalysis

Background:

• Development of efficient catalysts for ring-opening polymerization (ROP) is crucial for producing biodegradable polymers.
• Phenoxy-thioether ligands offer unique coordination environments for metal complexes.

Purpose of the Study:

• To synthesize and characterize novel magnesium(II) and zinc(II) complexes supported by phenoxy-thioether ligands.
• To evaluate the catalytic performance of these complexes in the ring-opening polymerization of cyclic esters.

Main Methods:

• Synthesis of novel Mg(II) and Zn(II) complexes using various precursors and ligands.
• Characterization using techniques such as NMR spectroscopy and Diffusion Ordered SpectroscopY (DOSY).
• Evaluation of catalytic activity in ring-opening polymerization of ε-caprolactone and lactide.

Main Results:

• Successfully synthesized and characterized six novel Mg(II) and Zn(II) complexes.
• Variable temperature NMR and DOSY experiments indicated the dimeric nature of the complexes in solution.
• All synthesized complexes demonstrated catalytic activity in ROP.
• Magnesium complexes exhibited superior performance in terms of activity and control over molecular weights and distributions for ε-caprolactone and lactide ROP.

Conclusions:

• The novel phenoxy-thioether supported Mg(II) and Zn(II) complexes are effective catalysts for ROP.
• Magnesium complexes display enhanced catalytic properties, making them promising for biodegradable polymer synthesis.