Light-driven Hydrogen Evolution from Water by a Tripodal Silane Based Co^II₆L¹₈ Octahedral Cage

The octahedral cage assembly [Co^II₆L¹₈Cl₆(H₂O)₆]­Cl₆ has been synthesized in a single-step reaction by using a polypyridyl-functionalized tripodal silane ligand. The electrochemical behavior of the cage in water exhibits the pH dependence of potential as well as catalytic current indicating the possible involvement of proton-coupled electron transfer in H₂ evolution. Electrocatalytic hydrogen evolution from an aqueous buffered solution gave a turnover frequency of 16 h^–1. Further, this cage assembly has been explored as a photocatalyst (blue light irradiation λ 469 nm) for the evolution of H₂ from water in the presence of Ru­(bpy)₃²⁺ as a photosensitizer and ascorbic acid as a sacrificial electron donor. This catalytic reaction is found to be pseudo first order with a turnover frequency of 20.50 h^–1

Acetylcholinesterase and Aβ Aggregation Inhibition by Heterometallic Ruthenium(II)–Platinum(II) Polypyridyl Complexes

Two heteronuclear ruthenium­(II)–platinum­(II) complexes [Ru­(bpy)₂(BPIMBp)­PtCl₂]²⁺ (<b>3</b>) and [Ru­(phen)₂(BPIMBp)­PtCl₂]²⁺ (<b>4</b>), where bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, and BPIMBp = 1,4′-bis­[(2-pyridin-2-yl)-1H-imidazol-1-ylmethyl]-1,1′-biphenyl, have been designed and synthesized from their mononuclear precursors [Ru­(bpy)₂(BPIMBp)]²⁺ (<b>1)</b> and [Ru­(phen)₂(BPIMBp)]²⁺ (<b>2</b>) as multitarget molecules for Alzheimer’s disease (AD). The inclusion of the cis-PtCl₂ moiety facilitates the covalent interaction of Ru­(II) polypyridyl complexes with amyloid β (Aβ) peptide. These multifunctional complexes act as inhibitors of acetylcholinesterase (AChE), Aβ aggregation, and Cu-induced oxidative stress and protect neuronal cells against Aβ-toxicity. The study highlights the design of metal based anti-Alzheimer’s disease (AD) systems