Comparison between mechanochemical and solution synthesis of Zn and Cu complexes containing pyridine and p-halogen substituted benzoates†

Mechanochemistry can be an essential tool for coordination chemistry, demonstrating significant advantages over solution protocols, enabling highly selective, efficient, and rapid syntheses with conversion of the reagents achieved within minutes of grinding. The mechanochemical synthesis of heteroleptic Zn(II) and Cu(II) complexes containing non-chelating ligands like pyridine and p-halogen-substituted benzoates showcased the potential of this technique, with a detailed comparison to solution-based synthetic methods. Structural analyses via X-ray diffraction confirm that the crystalline phases produced mechanochemically are identical to those obtained in solution. The synthesis of anhydrous complexes under dry mechanochemical conditions was also achieved without specialized equipment, highlighting the versatility of this approach even for moisture-sensitive compounds.