Inorganica Chimica Acta最新文献

Synthesis of heterodinuclear 3d transition metal complexes in which two metal ions are introduced in equivalent coordination sites of a ligand is quite uncommon. We have previously shown that the application of the cis–trans isomerization of the oxamido group was able to furnish such a possibility. In the present paper we demonstrate that this synthetic pathway, relying on the possibility of changing the conformation (cis vs trans) of the oxamido group, can be extended to other ligands. Although we have not been able to characterize these complexes by structural determinations, FAB-MS, EPR and magnetic data do confirm the efficiency of this reaction pathway. We also demonstrate that the cis–trans isomerization of the oxamido group is not due to a particular property of the ion involved in the reaction. In fact, isomerization is governed by the basicity of the reaction medium. According to the reaction condition, it is possible to favor or not this phenomenon, and to increase the accessibility to a larger number of novel genuine complexes. But the oxophilic character of the lanthanide ions limits the use of this synthetic pathway because it impedes this isomerization. Eventually, the very weak magnetic interactions observed in these Cu-Gd complexes can be explained thanks to spin polarization.

Pseudo-polymeric double complexes of [Au{S₂CN(C₄H₉)₂}₂][AgCl₂] (1) and [Au{S₂CN(CH₂)₆}₂]₃[AgCl₂][Ag_0.59Au_0.41Cl₂]₂ have been obtained and chemically identified using solution (¹H, ¹³C{¹H}) NMR and FT-IR spectroscopy. According to XRD analysis, it was established that both of the above crystalline compounds form complicated supramolecular architectures. Self-assembly and structural stabilization of these supramolecular formations are achieved due to numerous secondary interactions: Ag⋯S, Cl⋯S (in 1, 2) and Au⋯Cl, Au⋯S (in 2), which arose between the ionic structural units of the complexes. The combined manifestation of these interionic secondary interactions leads to the construction of two types of pseudo-polymeric chains of (⋯[Au(S₂CNBu₂)₂]⋯[AgCl₂]⋯)_n (1) and (⋯[Au₂(S₂CNHm)₄]⋯ [AgCl₂]⋯)_n (2). To study the thermal behaviour of the prepared compounds, the simultaneous thermal analysis (STA) technique was used, which allowed us to determine the conditions for the quantitative recovery of bound metals. Moreover, a high in vitro biological activity for each of the prepared gold(III)-silver(I) compounds against the non-pathogenic strain Mycolicibacterium smegmatis was experimentally revealed.

Metal-organic frameworks (MOFs) have emerged as promising materials for photocatalytic applications due to their tunable structures and exceptional surface areas. Among various types of MOFs, those based on titanium (Ti) and iron (Fe) have garnered significant attention for their potential in environmental remediation, energy conversion, and organic synthesis. This review paper comprehensively examines the recent advancements in the photocatalytic applications and synthetic strategies of Ti and Fe-based MOFs. In the first part, we provide an in-depth analysis of the synthetic strategies employed for the preparation of Ti and Fe-based MOFs with tailored photocatalytic properties. The second part of the review highlights the diverse photocatalytic applications of Ti and Fe-based MOFs, including environmental remediation through the degradation of organic pollutants, hydrogen evolution reaction (HER) for renewable energy production, carbon dioxide reduction for greenhouse gas mitigation, and catalysis of organic transformations. Overall, this review paper offers valuable insights into the current state-of-the-art in the field of Ti and Fe-based MOFs for photocatalytic applications, providing researchers and practitioners with a comprehensive understanding of the potential and limitations of these materials. The synthesis strategies discussed herein serve as guidelines for the rational design and development of highly efficient photocatalysts for various environmental and energy-related applications.

In this study, we synthesized two novel metal–organic frameworks [Cd(C₄H₄N₂)(C₁₂H₁₉P₃O₉)]n (1) and {Ca[Cd(H₂O)₃]₂(C₂₄H₁₅N₆O₆)₂}n (2) distinguished by exceptional fluorescence properties. Focusing on 1, we innovatively combined it with hydroxypropyl cellulose (HPC) to create a pH-responsive, fluorescence-guided nanocarrier system (HPC-1@DOX) for targeted delivery of doxorubicin (DOX) in cancer treatment. We thoroughly evaluated the loading and release efficiency of DOX under varied pH conditions, demonstrating sustained and controlled drug release characteristics in vitro, along with substantial drug-loading capacity. Notably, HPC-1@DOX exhibited pH-responsive behavior, releasing DOX preferentially at pH 6.8, indicative of targeted delivery to tumor and inflammatory sites while minimizing release at higher pH values. Moreover, we explored its biological impact, confirming HPC-1@DOX’s ability to up-regulate miR-493-3p expression in lung carcinoma cells, thereby inhibiting proliferation, reducing invasiveness, and inducing apoptosis. This multifunctional nanocarrier system represents a significant advancement towards targeted and effective cancer therapy.

In this work, pivalic acid (pivH) molecule is employed for an electrochemical sensing of copper cations in an aqueous medium. For sensitive as well as selective potential sensor application, pivH was fabricated onto a glassy carbon electrode (GCE) facilitated by adhesive conducting binder, nafion, so as make it selective and effective electrochemical probe (pivH/Nafion/GCE) towards specific heavy metal cations. This newly fabricated pivH/Nafion/GCE reveals enhance electrochemical activity toward copper ions in the presence of other interfering heavy metal cations in phosphate buffer solution (PBS) of pH=7. The calibration plot was linear (r² = 0.9879) across broad linear dynamic range (LDR) spanning Cu²⁺ concentration from 0.1 nM to 0.01 M. The sensitivity and detection limit was found to be 0.0212 × 10⁻² µAµM⁻¹cm⁻² and 0.014 nM, respectively. So, this newly fabricated GCE as selective electrochemical probe offers a sensitive as well as selective detection of Cu²⁺ cations in real environmental samples using a novel electrochemical, current–potential (I-V), approach, for the first time. Further, we explored pivalic acid for the preparation of new di-nuclear copper complex, [Cu₂(piv)₄(pivH)₂] (where piv = pivalate; pivH=pivalic acid) and characterized by Fourier transform infrared spectroscopy (FTIR) spectroscopy, elemental analysis and single crystal X-ray diffractometry. Density functional theory (DFT) calculations were carried out to confirm the interactions and these calculations well-support to experimental data. In case of deprotonated form of pivH, Molecular Electrostatic Potential (MEP) analysis exhibits electrostatic potential equals to −148.4 kcal/mol which suggest about the strong interaction of –COOH with copper centers. Similarly, interaction energies, the quantum theory of atoms in molecules (QTAIM) study and Natural Bond Orbital (NBO) analysis also favor to experimental work. Thus, this novel study demonstrates an excellent approach for highly selective and sensitive detection of Cu²⁺ cations in short response time with low detection limit and good reproducibility by using I-V method based on newly designed pivH/Nafion/GCE as selective Cu²⁺ cationic electrochemical sensor. The experimental data was compactable with theoretical calculations.

A new phosphorescent ruthenium-based receptor, designated as Ru-1, functionalized with imidazolium as an anion-binding moiety was synthesized and characterized for selective recognition and sensing of H₂PO₄⁻ and HP₂O₇³⁻. The binding affinity of Ru-1 towards numerous anions was assessed using UV–visible and phosphorescent spectroscopic techniques in CH₃CN solvents. Notably, phosphate and pyrophosphate exhibited superior binding constants compared to other anions, with measured binding constants (K_a) of 7.95 × 10⁴ and 4.78 × 10⁴ M⁻¹ respectively. Moreover, discernible blue shifts of 25 nm and 28 nm respectively, corresponding to H₂PO₄⁻ and HP₂O₇³⁻ and significant enhancements in photoluminescence intensities by ∼5-fold and ∼4-fold, respectively were observed with H₂PO₄⁻ and HP₂O₇³⁻. Despite the existence of excess other anions, Ru-1 demonstrated selectivity towards these ions, facilitating sensitive detection with a limit of detection (LOD) of 0.045 µM for H₂PO₄⁻ and 0.017 µM for HP₂O₇³⁻. In the presence of H₂PO₄⁻, the lifetime of Ru-1 was amplified noticeably from 0.2329 μs to 0.7914 μs, whereas exposure to HP₂O₇³⁻ resulted in an observed increase of 0.7465 μs. Furthermore, comparative photophysical studies revealed that the imidazolium moiety-based Ru-1 receptor outperformed the triazole-based Ru-2 receptor in terms of excited state lifetime, binding constant, and detection limit of the anions.

Different types of phenolic pollutants pose a major risk to the environment and the health of living things. It is therefore crucial for their selective recognition especially nitrophenols. In this work, yellow fluorescent carbon dots (C-dots) were used as selective nanoprobe to efficiently detect 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP). One-pot synthetic method was adopted for making C-dots from o-phenylenediamine and oleic acid mixture. The synthesized C-dots showed an excitation wavelength of 420 nm with Stokes shift of up to 135 nm. These C-dots exhibited instantaneous selective detection of 2-NP and 4-NP in aqueous solution with a detection limit of 6.4 nM and 4.8 nM respectively. Upon incubated with 2-NP and 4-NP, the C-dots’ fluorescence underwent quenching with a maximum extent of respective 80 % and 83 %. By comparing with other analogs of analyte, it was discovered that the emission intensity of the C-dots remained unchanged. Static quenching was proposed behind the changes of fluorescence after the treatment with 2-NP and 4-NP. Such type of C-dots will demonstrate the selective sensing platform in real field application.

Two new coordination polymers ({[Ag(p-phda)₂](BF₄)} _n (1) and {[Ag₂(1,5-nds)(DMSO)₂] DMSO}_n (2) (p-phda: p-phenyldiacetonitrile, 1,5-nds: 1,5-naphthalene disulfonic acid, DMSO: dimethyl sulfoxide) were synthesized and characterized by IR, EA,TG and X-ray single crystal diffraction. 1 was revealed as a 2D “fishing net” assembled by AgN bonds with BF₄⁻ as equilibrium charge. IR and PXRD analysis showed the BF₄⁻ can be irreversibly exchanged by six anions varied in atomic numbers, sizes, configurations and coordination abilities. 2 is constructed by AgO bonds where DMSO function both as guest and bridging ligand. Further diffusion of NO into the solution of 1 and 2 generated two new compounds (1′ and 2′). All four compounds showed excellent broad-spectrum antimicrobial activities against gram-negative bacteria, gram-positive bacteria and yeast. The stronger antibacterial abilities of 1 against S. aureus and P. aeruginosa than those of 2 were evidenced by the smaller minimum inhibitory concentrations of silver ions (AgMICs) and the higher silver ion release rate in aqueous solution. It was concluded that the looser packing of 1 facilitate the silver ions releasing and play a more crucial role than binding mode and ligand-exchangeability. The enhanced P. aeruginosa inhibitions of 1′ and 2′ were elementarily ascribed to NO incorporation, supporting by their increased diameter of inhibition zones and decreased AgMICs.

A novel and highly selective reactive sulfur ions (S^2-) probe, 4′-(benzo[d]thiazol-2-yl)-3′-((7-nitrobenzo[c][1,2,5] oxadiazol-4-yl) oxy)-N, N-diphenyl-[1,1′-biphenyl]-4-amine (DBA), has been synthesized through covalent bonding of a 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) unit with 4-(benzo[d]thiazol-2-yl)-4′-(diphenylamino)-3-phenylphenol (BO-OH). The structure was meticulously characterized using a combination of IR, NMR, HRMS, and LC-MS techniques. Notably, upon the addition of S^2-, the fluorescence of the probe DBA solution underwent a marked enhancement, transitioning from nearly colorless to brilliant yellow-green luminescence. The Ultraviolet–visible absorption spectrum and fluorescence emission were utilized to assess the probe DBA efficacy in detecting and identifying S^2-. It exhibited a substantial fluorescence amplification, enabling quantitative detection within a concentration range of 0 to 17.1 μM, and possessed a low detection limit of 66.89 nM. Moreover, this method boasts a high recovery rate, excellent accuracy, and usefulness for analysis when tracking S^2- in real samples.

The innovative ligand H₂L, featuring a benzimidazole structure substituted with 8-hydroxyquinoline and equipped with N,O donor sites, underwent successful synthesis and meticulous characterization. Notably, this ligand was exclusively synthesized through catalysis under protonated conditions, accompanied by an in-depth exploration of the catalytic mechanism. Employing single-crystal X-ray diffraction, we acquired and authenticated four distinct asymmetric double-decker sandwich mononuclear transition metal complexes: [Cu(HL)₂]·2H₂O, [Co(HL)₂]·CH₃OH, [Ni(HL)₂] and [Zn(HL)₂]·CH₂Cl₂. Among these, complex 1 revealed an intriguing five-coordinate Cu(II) center adopting a distorted square pyramidal geometry, whereas the central metal ions in complexes 2–4 exhibited a six-coordinate configuration, characterized by a distorted octahedral geometry. Noteworthy is the observation that the dihedral angles within the crystal structures of complexes 2–4 approached approximately 90° to a significant extent. To delve deeper into the electronic properties and transitions, meticulous DFT and TD-DFT calculations were performed on both the ligand H₂L and complexes 1–4. Furthermore, a comprehensive investigation into the luminescence properties of both H₂L and its complexes was conducted, revealing a pronounced luminescence quenching effect in the complexes compared to the ligand. Through thorough analysis utilizing Hirshfeld surface examination and IRI analysis, various weak intermolecular interactions within the system were elucidated.