Inorganica Chimica Acta最新文献

Seeing the frontier molecular orbitals (FMO) picture of β-d-glucopyranose–silver+ (1:1) complex ([Ag(C₆H₁₂O₆)]⁺) reported in a recent article (Mondal, 2024) [53], we used the FMO based approach to obtain inverted sandwich like organometallic complex comprising X₃ (X=Be, Mg) core, in silico. Thermodynamic feasibility of obtaining [(C₆H₁₂O₆)Ag-X₃-Ag(C₆H₁₂O₆)] (X=Be, Mg) complexes are explored. Conceptual density functional theory (CDFT) based reactivity descriptors guide to ascertain the stability order of such complexes. By the help of natural bond orbital analysis, Wiberg bond indices (WBI), bond critical point analysis, electron density descriptors, and gradient isosurface between selected contacts, the nature of interaction between the X₃ core and Ag metals are studied. FMO of the complexes further help in ascertaining the nature of binding. Energy decomposition analysis marks the interaction between X₃ and Ag metals in [(C₆H₁₂O₆)Ag-X₃-Ag(C₆H₁₂O₆)] (X=Be, Mg) as partially covalent. Negative values of nucleus independent chemical shift (NICS) at the triangular ring (X₃) centres [NICS(0)] indicate aromatic property.

The synthesis of original 6-(azol-1-yl)phenanthridine ligands and a copper(II) complex based on them is reported. Comprehensive studies of the structural, physicochemical, and electrocatalytic properties for the selected 6-(1H-pyrazol-1-yl)phenanthridine-containing coordination compound have been carried out. The latter has demonstrated pronounced electrochemical and electrocatalytic activities in the enzyme-free cholesterol oxidation in DMSO. A six-stage mechanism including electrocatalytic reduction of cholesterol and subsequent oxidation of its reduction products has been proposed and underpinned by quantum mechanical considerations. Obtained analytical characteristics of the enzyme-free cholesterol oxidation (LoD 0.0032 mM, detectable concentrations 0.01–0.40 mM) open a prospect towards the investigated complexes to be applied as sensitive elements of portable electrochemical platforms for the point-of-care diagnostics.

The depletion of traditional fossil fuels, as well as the increase in global energy demand, is currently driving the need for sustainable energy solutions. The primary challenge in the practical application of hydrogen fuel cells is to reduce or replace the use of platinum material in the electrode catalysts. In this work, by using density functional theory (DFT) we investigate the oxygen reduction reaction of Ag-based core-shell nanoclusters with 12 different 3d-5d transition metal (TM) cores (groups 8–11). The stability is assessed by calculating the binding, excess and segregation energies, indicating that the most stable mixing is found in the noble metal-encapsulated structures, such as Pd@Ag, Pt@Ag, Rh@Ag and Ir@Ag particles. The reaction barrier for OH formation is found to be the limiting step with values ranging from 0.59 to 1.36 eV among the core-shell Ag-based nanoclusters, which are comparable with the energy barrier of the Pt(111) surface (0.97 eV). However, the correlation of the d-band center and activation barriers indicate that Ru@Ag, Rh@Ag, and Os@Ag mixings are the most suitable for the oxygen reduction reaction. These results indicate that small Ag-based core-shell nanoclusters with transition metal cores are active for the ORR application in alkaline media.

This review centres on the synthesis of zirconium(IV) complexes using Schiff base ligands. The first section provides a brief introduction to Schiff bases and zirconium(IV) complexes. In the second section, the synthesis of Schiff base zirconium(IV) complexes is explored through literature spanning from 2001 to 2022. The most important third section is divided into four subsections covering these complexes’ physical, spectroscopic, X-ray, and thermal studies. The fourth section summarizes the broad range of remarkable catalytic (polymerization and condensation) and biological (antibacterial, antifungal, anti-inflammatory, larvicidal) properties exhibited by Schiff base zirconium(IV) complexes.

Acetate complexes of rare earth elements are extensively studied compounds known for their diverse properties and potential applications and lanthanum acetate hydrate is commercially available. In this work, a powdered anhydrous lanthanum acetate (La(CH₃COO)₃) sample was prepared by dissolving lanthanum oxide (La₂O₃) in an excess of acetic acid (CH₃COOH) and distilled water (H₂O), followed by direct evaporation at 150 °C. The decomposition of La(CH₃COO)₃ was studied, showing initiation around 300 °C and conclusion at ≥700 °C, with four distinct thermal events (I–IV) of mass loss. Gas phase identification revealed acetone and carbon dioxide as decomposition products, indicating pyrolytic decarboxylation. The final thermal effect (IV) is linked to the decomposition of La₂O₂CO₃ to La₂O₃. The DFT refinement of atomic coordinates of hydrogen atoms, which were unavailable from experiment, was successfully performed. Obtained structural data was checked using vibrational spectroscopy method. The calculated electronic band structure of La(CH₃COO)₃ indicates it as an indirect wide band gap material with values of direct transition close to indirect. The optical bandgap is found to be 5.49 eV, suggesting that the charge transfer in La(CH₃COO)₃ can be optically activated with wavelengths shorter than 226 nm, which falls within the deep UV (DUV) region.

Highly luminescent octa-coordinated samarium(III) complexes including [Sm(TFDH)₃(Bpy)] (Sm1), [Sm(TFDH)₃(S₁)] (Sm2), [Sm(TFDH)₃(S₂)] (Sm3) and [Sm(TFDH)₃(S₃)] (Sm4) were synthesized utilizing fluorinated β-diketone i.e. 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFDH) and bidentate auxiliary ligands. Here, S₁ is 5,5ʹ-dibromo-2,2′-bipyridine; S₂ is 5-bromo-5ʹ-(3,4-(ethylenedioxy)thien-2-yl)2,2′-bipyridine and S₃ is 5,5′-bis(3,4-(ethylenedioxy)thien-2-yl)2,2′-bipyridine. Different properties of prepared complexes were examined using numerous characterization techniques such as elemental, FT-IR, ¹H NMR, absorption and thermogravimetric analyses. Nuclear magnetic resonance (NMR) data affirms the coordination of three TFDH units and one bidentate ligand with metal ion in each complex. Sm(III) complexes exhibit thermal stability up to 250 °C when subjected to an inert atmosphere composed of nitrogen (N₂) gas. The luminescent characteristics of the powdered Sm1-Sm4 complexes were also investigated. Each complex displays distinct peaks at around 564, 605, 648 and 707 nm in their emission profiles. The orange-red emission of these complexes was observed via colorimetry which strongly aligns with the highly intense peak observed at 648 nm (⁴G_5/2→⁶H_9/2). The strong luminosity and color coordinates suggest that the complexes could serve as potential candidates for use in OLEDs and display panel.

Owing to the biological importance of copper(II) coordination complexes, herein, a new mononuclear complex, [Cu(Eta)₂(CNBz)₂], where CNBz = 4-chloro-3-nitrobenzoate, Eta = ethanolamine, was isolated using an appropriate stoichiometric ratio of reactants under ambient reaction conditions. The newly synthesized complex was substantiated by applying various analytical methods such as elemental analysis, and FT-IR. The complex crystallized in monoclinic crystal system with P2₁/n space group. Single X-ray crystal structure elucidation delineate the formation of layer by layer fashion of complex molecules which was further stabilized by multitude of non-covalent ineteractions especially hydrogen bonding. The quantitative estimation of these interactions was carried out using Hirshfeld surface analysis and theoretical calculations. The potential antibacterial activity of the complex was demonstrated by in-vitro and in-silico antibacterial experiments. The attained significant results delineate the crucial role of various functionalities in the complex in rendering interactions with various amino acid units in the protein thereby influencing the biological activities. In nutshell, coordination complexes, when ligands employed were endowed with various donor and acceptor functional groups will influence the lattice stabilization as well as biological efficacy of such complexes.

Two imidazolidine grafted Schiff bases H₃L₂ and H₃L₃ have been utilized to fasten the Cu₂ core in four new complexes [Cu₂(μ-L₂)(μ-O₂CMe)]·H₂O (1·H₂O), [Cu₂(μ-L₂)(μ-O₂COMe)]·H₂O (2·H₂O), [Cu₂(μ-L₂)(μ-NO₃)]·H₂O (3·H₂O) and [Cu₂L₃(μ-OAc)]·5H₂O (4·5H₂O). Room temperature solution reaction of H₃L₂ with Cu₂(OAc)₄·2H₂O provided 1·H₂O in good yield. Follow-up reaction of 1·H₂O with Et₄NOH in air replaces μ-O₂CMe (acetato) bridge by MeOCO₂⁻ (monomethyl carbonato) linker in 2·H₂O. Single crystal X-ray structure established the individual complexes and confirmed the fixation of atmospheric CO₂. Variable temperature (2 to 300 K) magnetic susceptibility measurements recognized the antiferromagnetic exchange interactions between the adjacent copper(II) centers in complexes 2 and 3. The amount of spin–spin interactions are found to be higher for ancillary NO₃⁻ bridge (−284  cm⁻¹) compared to the in situ transformed MeOCO₂⁻ bridged (−1.64  cm⁻¹).

In this review article, we present a brief survey of the recent contributions (2018–2024) appeared in the scientific literature, describing the use of the cage-like water-soluble monodentate phosphine 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane (also known as 1,3,5-triaza-7-phosphadamantane, PTA), some of its derivatives and a higher homologue as stabilizing ligands for precious and non-precious metal complexes, with various applications in homogeneous catalytic processes in water and biphasic media.

Two coordination polymers (CPs), [Cd₃(L)₃(phen)₂]_n (1) and [Mn(L)(phen)]_n (2), [H₃L=3,3′-(1,4-phenylenebis(methylenoxy)dibezoic acid] were synthesized via hydrothermal method. 1 features a 2D layered structure with the potential for 3D network formation through weak interactions, 2 exhibits a 1D waved chain capable of forming 3D polymeric chains via intra- or intermolecular hydrogen bonding (OH···O) interactions. Both CPs demonstrate promising photocatalytic activity against antibiotics, including chloramphenicol (CAP), metronidazole (MDZ), nitrofurazone (NFZ), oxytetracycline (OXY), and sulfamethazine (SMZ). Notably, CP 1 shows superior photocatalytic activity for NFZ degradation. Systematic investigations revealed that under optimized conditions, CP 1 achieves a remarkable ∼ 92.21 % photodegradation of NFZ at a concentration of 40 ppm NFZ with a photocatalyst dosage of 25 mg/L within 50 min. Radical quencher experiments identified h⁺ (positive holes) and O₂^•- as the primary active species driving the photodegradation process. Additionally, CP 1 maintained consistent performance over five cycles, indicating its stability and reusability for NFZ degradation.