👤 Somnath Maji

Many heavy transition metal compounds are active redox catalysts. Their redox potentials can be offset by differential spin-orbit coupling (SOC) effects in the case of strong perturbation of the ground-state energy of the oxidized or the reduced state. However, SOC effects are often considered negligible in the case of organometallic species, anticipating energetically well-separated, nondegenerate spin ground states for metal ions in strong ligand fields with low symmetry. We here report a rhenium(III) aminodiphosphine complex that undergoes proton-coupled electron transfer with a phenoxyl radical as a hydrogen abstractor. Experimental derivation of the PCET thermochemistry shows a deviation from coupled-cluster computations in the range of 6 kcal·mol^-1. The deviation can be attributed to a sizable SOC contribution by the amine precursor, which is largely quenched in the rhenium(IV) amido product. Our case study emphasizes potential pitfalls for coupled-cluster benchmarking of the reaction energetics of heavy d-block catalysts. Show less

Tetrazoles are nitrogen-rich heterocycles that have attracted interest because of their numerous applications in pharmaceutical and medicinal chemistry. Four nitrogen atoms and one carbon atom make up these five-membered rings, which have special physicochemical and electrical characteristics, including acidity, resonance stabilization, and aromaticity. This article highlights the structure, spectroscopic characteristics, and physical and chemical characteristics of tetrazoles. It also describes how overlapping mechanisms, such as DNA replication inhibition, protein synthesis disruption, and oxidative stress induction, as well as similar therapeutic targets, enable inhibitors to serve as both antibacterial and anticancer agents. Tetrazole moieties have been fused with a range of pharmacophores, such as indoles, pyrazoles, quinolines, and pyrimidines, yielding fused derivatives that display substantial inhibitory activity against bacterial, fungal, and cancer cell lines, with certain compounds exhibiting efficacy comparable to or exceeding that of established therapeutic agents. The rational design of more efficacious tetrazole-based therapies is facilitated by structure-activity relationship analysis, which further highlights significant functional groups and scaffolds that contribute to increasing activity. We investigate the relationship between microbial inhibition and anticancer efficacy, opening up new avenues for the creation of multifunctional therapeutic agents. We hope that this study will offer significant guidance and serve as a valued resource for medicinal and organic researchers working on drug development and discovery in multifunctional therapeutics. The review involves a thorough investigation of tetrazole in recent years. Show less

Platinum-based anticancer drugs represented by cisplatin play important roles in the treatment of various solid tumors. However, their applications are largely compromised by drug resistance and side effects. Much effort has been made to circumvent the drug resistance and general toxicity of these drugs. Among multifarious designs, monofunctional platinum(II) complexes with a general formula of [Pt(3A)Cl] + (A: Ammonia or amine) stand out as a class of “non-traditional” anticancer agents hopeful to overcome the defects of current platinum drugs. This review aims to summarize the development of monofunctional platinum(II) complexes in recent years. They are classified into four categories: fluorescent complexes, photoactive complexes, targeted complexes, and miscellaneous complexes. The intention behind the designs is either to visualize the cellular distribution, or to reduce the side effects, or to improve the tumor selectivity, or inhibit the cancer cells through non-DNA targets. The information provided by this review may inspire researchers to conceive more innovative complexes with potent efficacy to shake off the drawbacks of platinum anticancer drugs. Show less