Structural and functional insights into metal complexes of 1,2,4-triazole Schiff bases: a review

Among five-membered nitrogen-rich heterocycles, 1,2,4-triazoles are known for their coordination and significant biological activity. It is observed that triazole-based Schiff bases exhibit enhanced antimicrobial, antifungal, anticancer, and other medicinal properties upon coordination with metal ions. Strong metal-binding ability of these heterocycles also led to wide-range applications in materials science, medicine and agriculture. These metal complexes display remarkable structural diversity, from the variable coordination modes of the ligands and the multiple oxidation states of the metal ions, which govern their geometry, nuclearity, and reactivity. Owing to their stability and versatile coordination behavior, these complexes are promising candidates for functional materials, catalysts, as well as biological and environmental applications. In this context, the present review focuses on the structural diversity and practical applications of metal complexes derived from 1,2,4-triazole Schiff bases reported over the past 15 years, highlighting their unique coordination features and multifunctional applications.