Search for: All records

Abstract The rare earth elements (REEs) are critical resources for many clean energy technologies, but are difficult to obtain in their elementally pure forms because of their nearly identical chemical properties. Here, an analogue of macropa, G‐macropa, was synthesized and employed for an aqueous precipitation‐based separation of Nd³⁺and Dy³⁺. G‐macropa maintains the same thermodynamic preference for the large REEs as macropa, but shows smaller thermodynamic stability constants. Molecular dynamics studies demonstrate that the binding affinity differences of these chelators for Nd³⁺and Dy³⁺is a consequence of the presence or absence of an inner‐sphere water molecule, which alters the donor strength of the macrocyclic ethers. Leveraging the small REE affinity of G‐macropa, we demonstrate that within aqueous solutions of Nd³⁺, Dy³⁺, and G‐macropa, the addition of HCO₃⁻selectively precipitates Dy₂(CO₃)₃, leaving the Nd³⁺−G‐macropa complex in solution. With this method, remarkably high separation factors of 841 and 741 are achieved for 50 : 50 and 75 : 25 mixtures. Further studies involving Nd³⁺:Dy³⁺ratios of 95 : 5 in authentic magnet waste also afford an efficient separation as well. Lastly, G‐macropa is recovered via crystallization with HCl and used for subsequent extractions, demonstrating its good recyclability. 

Ischemia-reperfusion injury (IRI), which describes the cell damage and death that occurs after blood and oxygen are restored to ischemic or hypoxic tissue, is a significant factor within the mortality rates of heart disease and stroke patients. At the cellular level, the return of oxygen triggers an increase in reactive oxygen species (ROS) and mitochondrial calcium (mCa2+) overload, which both contribute to cell death. Despite the widespread occurrence of IRI in different pathological conditions, there are currently no clinically approved therapeutic agents for its management. In this Perspective, we will briefly discuss the current therapeutic options for IRI and then describe in great detail the potential role and arising applications of metal-containing coordination and organometallic complexes for treating this condition. This Perspective categorizes these metal compounds based on their mechanisms of action, which include their use as delivery agents for gasotransmitters, inhibitors of mCa2+ uptake, and catalysts for the decomposition of ROS. Lastly, the challenges and opportunities for inorganic chemistry approaches to manage IRI are discussed. 

Abstract The mitochondrial calcium uniporter (MCU) mediates uptake of calcium ions (Ca²⁺) into the mitochondria, a process that is vital for maintaining normal cellular function. Inhibitors of the MCU, the most promising of which are dinuclear ruthenium coordination compounds, have found use as both therapeutic agents and tools for studying the importance of this ion channel. In this study, six Co³⁺cage compounds with sarcophagine‐like ligands were assessed for their abilities to inhibit MCU‐mediated mitochondrial Ca²⁺uptake. These complexes were synthesized and characterized according to literature procedures and then investigated in cellular systems for their MCU‐inhibitory activities. Among these six compounds, [Co(sen)]³⁺(3, sen=5‐(4‐amino‐2‐azabutyl)‐5‐methyl‐3,7‐diaza‐1,9‐nonanediamine) was identified to be a potent MCU inhibitor, with IC₅₀values of inhibition of 160 and 180 nM in permeabilized HeLa and HEK293T cells, respectively. Furthermore, the cellular uptake of compound3was determined, revealing moderate accumulation in cells. Most notably,3was demonstrated to operate in intact cells as an MCU inhibitor. Collectively, this work presents the viability of using cobalt coordination complexes as MCU inhibitors, providing a new direction for researchers to investigate. 

We have investigated the biological properties of the osmium analogue of a potent ruthenium-based mitochondrial calcium uniporter inhibitor and have found it to possess distinct properties.