Inorganica Chimica Acta最新文献

The rapid detection of pollutants in the environment is of great significance. In this work, a novel MOF, namely [Zn(TPPA)(L)]_n (1) has been synthesized based on a π-electron rich triangular ligand TPPA (TPPA=tris(4-(pyridin-4-yl)phenyl)amine and H₂L=2,3-dihydrothieno[3,4-b][1,4]dioxine-5,7-dicarboxylic acid). Compound 1 is a 3-fold interpenetrating (3,5)-connected 3D framework. Photoluminescence studies indicate that the emission of 1 result from the charge transfer transition between ligands (π → π*). 1 with excellent luminous performance can be applied as a multi-functional chemical sensor for nitroaromatic compounds (NACs), toxic metal ions and antibiotics, and quick response. In addition, 1 exhibits photocatalytic activity for the degradation of methyl orange (MO) in the visible regions and is stable during the photocatalysis process. The effective detection of NACs and antibiotics was rationalized by density functional theory (DFT) calculation of the energy bands of NACs and antibiotics, which revealed that photoinduced electron transfer (PET) mechanism is largely responsible for the sensing of NACs. PET mechanism and resonance energy transfer play significant roles in the exclusive sensing of tetracycline hydrochloride (TCH).

Rare homoleptic divalent chromium complexes have been isolated by reacting two equivalents of sterically bulky deprotonated 2–aminopyridine ligands, N–(2,4,6–trimethylphenyl)–[6–(2,4,6–trimethylphenyl)–pyridine–2–yl]–amine (1), N–(2,6–diisopropylphenyl)–[6–(2,6–dimethylphenyl)–pyridine–2–yl]–amine (2) and N–(2,6–diisopropylphenyl)–[6–(2,4,6–trimethylphenyl)–pyridine–2–yl]–amine (3) with CrCl₂ in tetrahydrofuran (THF). Reaction of deprotonated 1 proceeds smoothly at room temperature while that of sterically more bulky 2 and 3 at reflux temperature. The respective bis(aminopyridinate) Cr complexes (4–6) are monomeric and show different orientations of the coordinated ligands. For compound 5, two isomers were identified. For 4 and 5a the two ligands show head to tail arrangement while in 5b and 6 the two ligands adopt the unknown head to head arrangement of aminopyridinato ligands. All the complexes show distorted square planar geometries around the chromium center. For 4 and 5a in which the ligands are coordinated in transoid manner the pyridine rings and amido nitrogen atom lie in the coordination plane of chromium. Hirshfeld analyses showed that H∙∙∙H and H∙∙∙C/C∙∙∙H π–interactions were the main and at times the strongest contributions for the intermolecular interactions.

In this work, we have synthesized six coordination polymers using the organic ligand 3-carboxy-1-(3′-carboxybenzyl)-2-oxidopyridinium (H₂L). The compounds, named [Co(L)(H₂O)₂]_n (1), [Co(L)(2,2′-bpy)(H₂O)]_n (2), [Co(L)(4,4′-bpy)_0.5]_n (3), [Mn₂(L)₂(H₂O)₂]_n (4), [Mn(L)(2,2′-bpy)(H₂O)]_n (5) and [Mn(L)(phen)(H₂O)]_n (6), where 2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine and phen = 1,10-phenanthroline, were prepared under hydrothermal conditions and characterized using various physical measurements. The single-crystal X-ray diffraction analyses show that compounds 1–6 possess different structures because of multiple coordination modes and weak interactions. The Hirshfeld surface analyses of compounds 1–6 have also been studied in detail.

A novel N,N’-dimethylethylenediamine derivative of substituted bis(phenol)diamine ligands, namely 2-(tert-butyl)-4-methylphenol in H₂L¹, was synthesized by a convenient green procedure. Nickel)II) complex [NiL¹] 1 has been synthesized and characterized by various methods along with crystal structure determined. Ni(II) coordination center in a mononuclear complex is surrounded by two phenolate oxygen atoms and two amine nitrogen atoms of the ligand in a square planar arrangement. The magnetic susceptibility of the title complex indicates a paramagnetic behavior above 150 K, while strong ferromagnetism below 100 K. Furthermore, the cyclic voltammetry studies show two ligand-centered oxidation of the phenolate groups to phenoxyl radical and the metal-centered reduction of Ni(II) to Ni(0). The Glaser coupling reaction of phenylacetylene was also studied. A strong catalytic activity at room T in THF solvent is observed for 1 in the presence of zinc powder as a reducing agent. A full conversion rate was achieved after 7 h at 25 °C. The DFT analysis corroborates with the square-planar NiO₂N₂ chromophore of 1 being reduced in catalytically active Ni(0) by applied Zn. The calculated Gibbs free energy of the reaction leading to the formation of the substrate Ni-complex is favorable endothermic. Most of the data for 1 were obtained also for the very similar previously reported [NiL²] 2, with 2,4- di tert-butylphenol in H₂L², which were than compared.

Reactions of N‚N’-bis(3-methylpyridyl)oxalamide (L¹), N‚N’-bis(3-methylpyridyl)adipoamide (L²) or N‚N’-bis(3-methylpyridyl)sebaamide (L³) with 1,2,4,5-benzenetetracarboxylic acid (1,2,4,5-H₄BETC) and metal salt yield four coordination polymers: {[Cu₂(L¹)₂(1,2,4,5-BTEC)(H₂O)]·5H₂O}_n, 1, [Cu₂(L²)(1,2,4,5-BTEC)(H₂O)₄]_n, 2, [Cu₂(L³)(1,2,4,5-BTEC)(H₂O)₄]_n, 3, and [Ni(L²)(1,2,4,5-BTEC)_0.5(H₂O)₂]_n, 4. These polymers have been structurally characterized using single crystal X-ray crystallography. Complex 1 forms a 3D framework adopting a new (4.6²)₂(4².6².8²)(4².6⁴.8⁴)₂(6³.8³) topology, whereas the others display 2D layers with the bex topology for 2 and 3, and a rare 4,4L88 topology for 4. The structural diversity of these coordination polymers is influenced by the combined effects of metal identity and ligand flexibility, supported by the 1,2,4,5-BTEC^4- ligand. Their thermal properties have also been investigated.

Three Cu(II) complexes (CTS1-CTS3) of acenaphthene quinone thiosemicarbazone with various N-terminal substitutions were synthesized. The prepared compounds were characterized via different spectroscopic analyses. The square planar structure formed by the ligands with Cu(II) (tridentate manner, ONS donor) is confirmed through EPR spectral analysis. The DNA binding studies performed using UV–visible and fluorescence spectroscopy point out that, all complexes showing significant interaction with DNA and CTS2 were the strongest (K_b = 6.46 × 10⁶ M⁻¹ & K_app = 2.5 × 10⁶ M⁻¹). A similar binding trend is observed towards the BSA protein (CTS2 with high K_b value, 1.76 × 10⁵ M⁻¹). The docking studies with EGFR protein (PDB ID: 5EDQ) reveal that CTS2 has the highest affinity towards them with a docking energy of − 7.41 Kcal/mol. The DFT investigations account for the stability (CTS3 has better structural stability with a high band gap, 0.10634 eV) and biological activity of complexes (CTS2 has a stronger biological activity due to its low ω value, 0.5864 eV). The lipophilicity (LogP ˃ 5) values obtained via Swiss-ADME studies are satisfactory and indicate that all 3 complexes have the potential to function as good oral drug candidates. The MTT assay results showed that CTS2 was the most effective against human breast (MCF-7), lung (A549), and cervical (HeLa) cancer cell lines, with IC₅₀ values of 11.5, 43.9, and 19.6 μM, respectively. Conversely, CTS2 showed the least cytotoxicity (IC₅₀ = 79.7 μM) when it came to normal (Vero) kidney epithelial cells.

The series of titanium (IV) complexes trans-[TiCl₄(OPPh₃)₂] (1), trans-[TiBr₄(OPPh₃)₂] (2) and trans-[TiI₄(OPPh₃)₂] (3) were obtained as polycrystalline powders by heating the corresponding metal tetrahalides with triphenylphosphine oxide in evacuated sealed glass ampoules. The crystal structures were determined by single crystal X-ray diffraction. Compounds 1 and 2 were isolated as yellow and brown crystalline powders, with yields 70 and 75%, respectively. This paper discusses the synthesis of these coordination compounds 1–3 and their crystal structures, and analyzes the geometric parameters of the related molecular complexes of niobium and rhenium for use in the design of magnetically diluted systems.

In this paper, the coordination of 4-methylpyrazole (L) to Ni(II) and Zn(II) ions is studied through the reactions of Ni(OAc)₂·4H₂O and Zn(OAc)₂·2H₂O with 4-methylpyrazole in a 1:2 metal-to-ligand molar ratio in ethanol at room temperature. From the reaction mixtures, new complex compounds of formulae: [Ni(OAc)₂L₄] and [Zn(OAc)₂L₂] were crystallized. The crystal and molecular structure of the synthesized complexes were determined by single-crystal X-ray structure analysis. The coordination environment of Ni(II) in its complex is octahedral, while that of Zn(II) is tetrahedral. The compounds are characterized by IR spectra and elemental analysis. Their thermal stability, a crucial property, is analyzed by thermogravimetry. To get a better insight into the decomposition mechanism coupled TG-MS measurements were carried out, too. The tests of the antioxidative activity of the new complexes on DPPH radical showed that the Zn(II) complex is more effective than the Ni(II) complex.

Halochromism has a plethora of uses in the textile industry, including wound treatments and protective apparel. Reactive dye’s fastness and a wide variety of hues, from bright to dull, make it ideal for coloring cotton and other regenerated cellulose fibers. It is also fundamentally paramount importance to determine the freshness of packaging foods. In this study, a halochromic probe, 4,4′-((1E,1′E,3E,3′E)-hydrazine-1,2-diylidenebis(prop-1-en-1-yl-3-ylidene))bis(N, N-dimethylaniline), HDBD, has been introduced utilizing a simple condensation reaction. Through the protonation and deprotonation process with the addition of acid and base in the non-aqueous medium, HDBD shows visual colorimetric as well as ratiometric UV–visible absorption spectral change. A colorimetric paper strip-based experiment has been demonstrated to detect trace amounts of acid and its reversibility with bases in non-aqueous solvents. Further, a dip-stick experiment was also carried out for the detection of acid-base vapor in a wide range of concentrations. Furthermore, the overlapping indicator method is explored to estimate acid dissociation constants in the non-aqueous medium. Moreover, we have constructed the INHIBIT (INH) and IMPLICATION (IMP) molecular logic gates exploring the reversibility of HDBD due to the cascade introduction of acid-base as chemical encoded inputs. Utilizing a reversible and reproducible detecting method, we have constructed a molecular-scale additional memory device that demonstrates binary logic “Writing-Reading-Erasing-Reading” and “Multi-write” functions. This finding provides a new way for designing acid-base indicators, which could estimate the acid dissociation constants of various acids in the non-aqueous environment which is fundamentally important in the field of acid-catalyzed organic synthesis.

The geometrical and stability properties of Ru-doped silver clusters (Ag_nRu with n  = 1–13) are investigated by density functional theory (DFT) calculations. The results show that the Ru dopant adopts central positions in the lowest-energy structures of Ag_nRu clusters. The most stable structures found are planar and curved for n = 3–6, while for n = 6 onward the structures follow a pentagonal growth pattern. Interestingly for n = 10, we found a cage structure with fulfills the 18 electron rule. The relative stability of the clusters is further evaluated through energetic parameters such as ionization energy, electron affinity, second order energy difference and HOMO–LUMO gap. The results show that the most stable structures in this series are Ag₃Ru, Ag₆Ru and Ag₁₀Ru, as supported by electronic structure analyses. The plausible formation of the Ag₁₀Ru cluster as a superatomic species is rationalized with 1.64 eV of HOMO–LUMO gap and 6.23 eV of adiabatic ionization energy.