Highly Selective On-Surface Reactions of Aryl Propiolic Acids via Decarboxylative Coupling

Area of Science:

• Surface chemistry
• Polymer science
• Organic synthesis

Background:

• On-surface chemistry enables precise material synthesis.
• Classical Glaser coupling of aryl alkynes has selectivity limitations.

Purpose of the Study:

• Introduce aryl propiolic acids as novel monomers for on-surface polymerization.
• Investigate the mechanism and efficiency of decarboxylative Glaser coupling.
• Explore the synthesis of unsymmetric metal-organic polymers.

Main Methods:

• On-surface decarboxylative Glaser coupling of aryl propiolic acids.
• Scanning tunneling microscopy (STM) for analyzing transformations.
• Density functional theory (DFT) calculations for mechanistic studies.

Main Results:

• Aryl propiolic acids undergo decarboxylative Glaser coupling at lower temperatures with high selectivity.
• Successful polymerization of bis(propiolic acids) demonstrated.
• Compatibility with aryl bromide functionalities allows sequential reactions for unsymmetric polymers.

Conclusions:

• Decarboxylative Glaser coupling offers a superior alternative to traditional methods for on-surface polymerization.
• This approach facilitates the creation of complex, unsymmetric polymers with controlled architectures.
• The findings open new avenues in surface-confined polymer synthesis.