Aquation

About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.

A [ ¹ H, ¹⁵ N] Heteronuclear Single Quantum Coherence NMR Study of the Solution Reactivity of the Ruthenium‐Based Mitochondrial Calcium Uniporter Inhibitor Ru265

Abstract: The synthesis and characterization of the 15N-labeled analogue of the mitochondrial calcium uptake inhibitor [Cl(NH3)4Ru(μ-N)Ru(NH3)4Cl]3+ (Ru265) bearing [15N]NH3 ligands is reported. Using [1H,15N] HSQC NMR spectroscopy, the rate constants for the axial chlorido ligand aquation of [15N]Ru265 in pH 7.4 buffer at 25 °C were found to be k1=(3.43±0.03)×10−4 s−1 and k2=(4.03±0.09)×10−3 s−1. The reactivity of [15N]Ru265 towards biologically relevant small molecules was also assessed via this method, revealing that this complex can form coordination bonds to anionic oxygen and sulfur donors. Time-based studies on these ligand-binding reactions reveal this process to be slow relative to the time required for the complex to inhibit mitochondrial calcium uptake, suggesting that hydrogen-bonding interactions, rather than the formation of coordination bonds, may play a more significant role in mediating the inhibitory properties of this complex.

Studies on the kinetics and mechanism of redox decomposition of 1,2,6-trinitrotriamminecobalt(III) and 1,2,6-trinitrodiethylenetriaminecobalt(III) complexes in aqueous acid

Abstract: In aqueous acid media the title complexes undergo decomposition ultimately forming cobalt(II). Detailed analysis of the kinetic data reveals that the reactions proceed in two consecutive stages, the initial step being the faster one. Evidence has been presented that the initial faster step involves aquation releasing one NO 2 − ligand and forming an aquodinitro complex, which subsequently undergoes a slower intramolecular redox decomposition into Co2+. Each step, on the other hand, has been found to consist of two concurrent paths,viz. spontaneous and acid catalysed, respectively. Activation parameters corresponding to all these specific rate constants have been evaluated and a plausible mechanism for the overall reaction has been proposed.