Advances in the Biological Studies of Metal-Terpyridine Complexes: An Overview From 2012 to 2022

The compound 2,2′;6,2″ terpyridine has attracted significant interest in the fields of supramolecular chemistry, materials science, and coordination chemistry due to its unique properties, including intense non-radiative relaxation and low quantum yields. With its tridentate ligand capabilities stemming from three nitrogen atoms, terpyridine ligands have been extensively studied, particularly the 4′-functionalized variants. These ligands exhibit strong chelating and binding abilities towards various transition and rare earth metals, making them valuable in electrochemistry, biochemistry, and photophysical chemistry. However, their biological activity is the most intriguing aspect of metal-terpyridine complexes. These complexes have shown tremendous potential in biological systems, acting as anti-tumour and cell imaging agents. Their exceptional binding properties enable interactions with vital biological targets such as DNA, proteins, and enzymes, offering promising avenues for therapeutic interventions. Additionally, these complexes have proven to be effective sensors capable of recognizing biologically essential anions and amino acids. While numerous review articles have been published on metal-terpyridine complexes and their applications, there has been a notable gap in the literature since 2012, specifically focusing on the biological activity of these complexes. Hence, there is a need for an in-depth review article that explores the advancements in the biological activity of metal-terpyridine complexes over the past decade. Such a comprehensive overview would provide researchers in this field with valuable insights into the intricate interplay between terpyridine ligands and metal ions, shedding light on their potential for therapeutic applications and inspiring further investigations in this exciting area of research.