Inorganic Chemistry最新文献

Utilizing CO₂ for the synthesis of value-added chemicals offers an economically viable route while contributing to reducing greenhouse gas emissions. In this study, three ligands with N₂O₂ binding sites were designed and used to synthesize mononuclear three cobalt(III) complexes, 1–3, for catalytic activity in the N-formylation reaction. A comparative study was conducted using DMAB as a greener hydrogen donor compared to triethylsilane in the presence of CO₂ as a C1 source. All complexes were characterized by UV–Vis, FT-IR, and single-crystal X-ray analysis. Although complex 2 showed the highest activity, all three homogeneous complexes displayed comparable efficiency and were thus employed to develop magnetically separable nanocatalysts for improved recoverability and reusability. Immobilizing the Schiff base complexes onto graphene oxide, Fe₃O₄, and APTES yielded three magnetically separable GO@Fe₃O₄@APTES@CoL^1/2/3 nanocatalysts. The heterogeneous catalyst obtained from complex 2, i.e., GO@Fe₃O₄@APTES@CoL² (GOFeTESCoL²), was catalytically more efficient than the other two. This new heterogeneous magnetically separable nanocatalyst, GOFeTESCoL², was then characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, BET analysis, and X-ray photoelectron spectroscopy, which confirmed successful surface modification. GOFeTESCoL² is magnetically separable and can be reused for six cycles without any loss of catalytic activity or product yield. This reusability offers a cost-effective nonprecious metal-based catalytic approach that minimizes potential reaction losses.

Biaryl motifs are central in pharmaceutical drug design, yet conventional synthesis via palladium-catalyzed cross-coupling poses increasing sustainability and cost concerns. The study presented herein explores a greener alternative to palladium using iron(II) complexes supported by tetra-aza macrocyclic ligands for direct arylation of pyrrole with phenylboronic acids. Under aerobic conditions, the optimized [Fe²⁺L1(Cl)₂] complex of ligand Me₂Cyclam (L1; 1,8-dimethyl-1,4,8,11-tetraazacyclotetradecane) showed broad substrate compatibility across 23 derivatives, achieving yields up to 66%, and excellent tolerance for functional groups including halides, esters, and strong electron-deficient substituents. Systematic analysis of these results suggests that meta-substitution and mild electron-withdrawing effects favor reactivity, while bulky ortho-steric hindrance suppresses coupling. Mechanistic studies ruled out outer-sphere radical pathways and high-valent iron complexes but do suggest iron(III)-hydroperoxo species as the operative oxidant. Density functional theory (DFT) analysis was carried out on the boronic acid substrates to show that electron-withdrawing substituents enhance the boron electrophilicity and promote the proposed transmetalation step, positioning this step as a key target for mechanistic activation of the substrate. These findings highlight the potential of earth-abundant iron catalysts as sustainable, cost-effective platforms for C–C bond formation in complex molecular scaffolds.

The solid electrolyte Li₂ZrCl₆ has attracted significant attention due to its low cost and good compatibility with high-voltage cathode materials. Although it exhibits considerable ionic conductivity at room temperature, it still falls short of the requirements for widespread application. Doping has proven effective in enhancing the ionic conductivity of Li₂ZrCl₆. In this work, the potential of Li_2.5Zr_0.75Zn_0.25Cl₆, Li_2.25Zr_0.75Ga_0.25Cl₆, and Li₂Zr_0.75Ge_0.25Cl₆ as solid electrolytes is investigated using density functional theory and ab initio molecular dynamics simulations based on first principles, with the doping-induced enhancement mechanism analyzed at the atomic scale. Moreover, the electrochemical window and phase stability of these materials are examined by using the Pymatgen tool. Results indicate that the nature of the dopant and a lithium-rich strategy are key factors influencing the Li⁺ conductivity of Li_2.25Zr_0.75Ga_0.25Cl₆. Compared to pristine Li₂ZrCl₆, Li_2.25Zr_0.75Ga_0.25Cl₆ shows significantly improved ionic conductivity, attributed to a reduced migration energy barrier and additional migration pathways in the ab plane. Furthermore, more isosurfaces at the interface suggest that Ga³⁺ incorporation enhances Li⁺ conduction between Li₂ZrCl₆ and Li₂S. This study provides a microscopic understanding of how elemental doping improves ion transport, contributing to the development of advanced solid electrolytes and all-solid-state batteries.

The efficient separation of acetylene (C₂H₂) and carbon dioxide (CO₂) is of major practical importance but remains difficult because of their analogous physical properties. The dual-ligand strategy provides an effective approach to tailor pore structure and chemical microenvironments for enhanced functionality. Nevertheless, the structural controllability of metal–organic frameworks (MOFs) assembled from tetracarboxylic acids and azole ligands remains challenging. Herein, we report a unique pillar-layered MOF, Zn-TCPB-dmtrz, constructed based on a dual-ligand strategy, demonstrating the efficient separation of C₂H₂/CO₂. The coordination of different ligands generates 1D [Zn₄N₆]_n chains, which function as pillars to interconnect 2D layers into a rare pillar-layered structure. The combination of abundant N/O sites and hydrophobic pore environment achieves high C₂H₂ adsorption capacity and excellent C₂H₂/CO₂ separation ability. Furthermore, its relatively low C₂H₂ Q_st, competitive thermal stability, and recyclability underscore its practicality for C₂H₂/CO₂ separation. This study enriches the structural diversity of pillar-layered MOFs and demonstrates the controllable dual-ligand strategy based on tetracarboxylic acid and dmtrz ligands for advanced gas separation.