Exploring the Properties of Organometallic Lactone-Containing Poly(benzofuran-co-arylacetic Acid): Traditional Synthesis Versus Mechanosynthesis.

Abstract

This work describes the synthesis and characterization of novel organometallic polymeric frameworks derived from lactone-based poly(benzofuran-co-arylacetic acid) (PBAAA) ligands complexed with 3d transition metal salts (Co²⁺, Cu²⁺, Zn²⁺). Two distinct synthetic approaches were investigated: conventional solution-based methods and mechanochemical ball milling. A comprehensive spectroscopic evaluation was performed utilizing FTIR, XRD, UV-Vis, and XPS techniques to detail the structural characteristics of the synthesized materials. The thermal assessments were conducted using TGA and thermal conductivity, demonstrating that the chosen synthesis method has a significant impact on the crystallinity, coordination environment, and thermal transport characteristics of the resultant complexes. Remarkably, using the mechanosynthesis, the resulting organometallic polymer materials exhibited enhanced chain ordering and improved thermal conductivity, with a value of 0.32 W/mK, almost double that of the starting polymer. A correlation was identified among thermal conductivity, metal ionic radius, coordination number, and the synthesis method utilized. XPS analysis revealed the presence of multiple oxidation states and varied electronic environments, particularly in copper complexes. These had a direct effect on how they behaved when heated. These results show that mechanochemical synthesis is a useful and long-lasting method to make complex organometallic polymers with thermal properties that can be changed.