Prepared and characterized complexes formed by imine from 2,2,6,6-tetramethyl-3,5-heptanedione, involving samarium and zinc as the metal centers

A Schiff base ligand was prepared by reacting 2,2,6,6-tetramethyl-3,5-heptanedione (a diketone) with primary amines in both aliphatic and aromatic forms. The process employed was microwave-assisted, which is considered environmentally friendly because it eliminates the needed for solvents, lowers chemical hazards, and greatly accelerates reaction times compared to conventional methods. The resulting compounds were characterized using a comprehensive set of nuclear magnetic resonance (NMR) techniques, including ¹H-NMR, ¹³C-NMR, HSQC, and COSY experiments. These spectroscopic methods were crucial due to the structural ambiguity caused by tautomerism. The detailed analysis confirmed the successful formation of the imine (–C=N–) group, verified the ligand structures, and established a solid basis for their further use in coordination chemistry and potential biological activity testing. Overall, the results indicated that microwave-assisted synthesis provides a simple, energy-efficient, and environmentally friendly approach for preparing Schiff base ligands derived from diketones. This method can be extended to design a wide range of Schiff bases with tailored properties for use in catalysis, materials, and pharmaceutical applications.