Green Mechanochemical Routes to Synthesis, Catalysis, and Polymer Recycling

As the pursuit of environmentally friendly and sustainable methodologies intensifies, mechanochemistry is steadily emerging as a powerful and promising alternative, demonstrating that a wide range of chemical transformations can proceed efficiently with minimal or no solvent and significantly reduced waste generation. Unlike conventional solution-based approaches, mechanochemistry enables direct energy input through mechanical force, offering advantages in terms of efficiency, scalability, and environmental impact. Recognizing its growing importance in green chemistry and sustainable transformations, the International Union of Pure and Applied Chemistry has identified mechanochemistry as one of the top innovative technologies with the potential to revolutionize global sustainable development [1]. In parallel, complexes based on nitrogen- and phosphorus-donor ligands have been extensively investigated due to their broad applicability in medicine [2], catalysis [3], and advanced materials. Herein, [4] we present mechanochemistry as a unified and versatile platform that integrates complex synthesis, catalytic applications, and material degradation within a single sustainable framework. Mechanochemistry demonstrated remarkable potential in the efficient synthesis of a diverse library of metal–bipyridine complexes (Ru, Fe, Co, Pt, Pd, and Ir), consistently delivering near-optimal yields alongside excellent green metrics, including E-factor values approaching zero and environmental mass yields (EMY) close to 100. These results highlight the efficiency and sustainability of the mechanochemical approach compared to traditional synthetic routes. In a similar manner, mechanocatalysis was explored using Ru(PP)(NN)X2 complexes (where PP = diphosphines, NN = diimine ligands, and X = acetate or Cl), further demonstrating the applicability of mechanochemical protocols in catalytic transformations. Additionally, ongoing efforts are focused on the mechanochemical degradation of polymeric materials under basic conditions, including PLA, PBAT, PBS, and vitrimers. These studies have already yielded promising results, emphasizing the potential of mechanochemistry not only in synthesis and catalysis but also as an effective and sustainable strategy for polymer recycling and circular materials management.