Inorganica Chimica Acta最新文献

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.

A series of seven 1-isopropyl-5,6-dimethylbenzimidazolium chlorides with a range of benzyl substituents on their N3 position (1a–g) were synthesized and used as NHC ligand precursors to prepare the corresponding [PdCl₂(NHC)(Py)] complexes (2a–g). The structural analyses of all novel compounds were done by ¹H and ¹³C{¹H} Nuclear Magnetic Resonance Spectroscopy, Fourier Transform Infrared Spectroscopy, and elemental analysis was also performed to evaluate the purity of the complexes. Also, the solid state structures of complexes 2d and 2g have been determined by the X-ray crystallography technique. Under optimized reaction conditions, the catalytic activity of the palladium complexes was tested by direct arylation of 2-n-propylthiazole, 2-n-propylfuran, and 2-n-propylthiophene with various aryl halides at 120 °C for 1 h and 3 h. It was observed that palladium complexes gave high yields and were selective at the C5-position of heteroaryl derivatives. Complex 2g, with an NHC N3-substituted by a 2,3,4,5,6-pentamethylbenzyl group showed the highest conversion probably due to the flexibility, the electronic and mostly the steric effects of this group.

The reactivity of trimetallic clusters [Os₃(CO)₁₀(NCMe)₂], [M₃(CO)₁₀(µ-dppm)] [M = Os, Ru; dppm = bis(diphenylphosphino)methane] and [Os₃(CO)₈{µ₃-Ph₂PCH₂PPh(C₆H₄)}(µ-H)] with triphenylarsine (AsPh₃) has been investigated. The labile [Os₃(CO)₁₀(NCMe)₂] reacts with AsPh₃ at room temperature to give 1,2-[Os₃(CO)₁₀(AsPh₃)₂] (1) in good yield. Thermolysis of 1 in refluxing toluene affords the known clusters [Os₃(CO)₁₁(AsPh₃)] (2), [Os₃(CO)₉(µ-AsPh₂)(µ₃,η²-C₆H₄)(µ-H)] (3) and [Os₃(CO)₇(µ-AsPh₂)₂(µ_3,η²-C₆H₄)] (4). Treatment of [Os₃(CO)₁₀(µ-dppm)] with AsPh₃ in refluxing toluene affords [Os₃(CO)₉(AsPh₃)(µ-dppm)] (5) as the major product together with [Os₃(CO)₇(AsPh₃){µ₃-Ph₂PCH₂PPh(C₆H₄)}(µ-H)] (6). Control experiment shows that 5 is a precursor of 6 as the former converts to the latter under similar experimental conditions. The same reaction affords 5 as the sole product when it is carried out in refluxing benzene. Cluster 5 and 6 can also be obtained in similar yield by treating [Os₃(CO)₈{µ₃-Ph₂PCH₂PPh(C₆H₄)}(µ-H)] with AsPh₃ at room temperature. On the other hand, the reaction of [Ru₃(CO)₁₀(µ-dppm)] with AsPh₃ in refluxing toluene furnishes only [Ru₄(CO)₈(µ-CO)(μ₄-AsPh)(µ₄,η²-C₆H₄)(µ-dppm)] (7) in low yield. Cluster 7 can also be obtained by heating [Ru₃(CO)₉(AsPh₃)(µ-dppm)] in refluxing toluene. It contains a phenylarsinidene and a benzyne ligands that were formed by AsC bond cleavage during the reaction. The molecular structures of all the new products have been established by X-ray crystallography.

In search for antitumor metal-based drugs that would mitigate the severe side-effects of cisplatin, Ru(II) complexes are gaining increasing recent interest. Their cytotoxic effect is widely known, however mechanism of action, solution behavior, redox reactions within biological system are still focus of the new studies. Various experiments and approach techniques are used to better understand ruthenium chemistry. In this order their biological activity and the availability of reduction potential in the biological medium, it is necessary to know their electrochemical redox behavior and properties. In this work, we report the electrochemical activity on synthesized and characterized (¹H- and ¹³C NMR, FT-IR, MS) half-sandwich organometallic Ru(II) complexes of the general formula [Ru(η⁶-arene)(XY)Cl](PF6) where arene = benzene, toluene or p-cymene and XY = bidentates: dipyrido[3,2-a:2′,3′-c]phenazine (dppz derivatives) or 2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline (aip), which are bound to Ru(II) via two phenanthroline-N atoms in a characteristic “piano-stool” configuration of Ru(II)-arene complexes – as confirmed by vibrational and NMR spectra. It is shown that selected complexes can be divided in four groups, based on their electrochemical behavior. These behaviors are correlated with their structure and nature of ligands.

The treatment of metal chlorides MCl₂ or metal chlorido complexes M(bpy)Cl₂ (M = Mn, Ni, Cu, bpy = 2,2′-bipyridyl) with TlPF₆ in acetonitrile to precipitate TlCl, followed by addition of excess nitrosobenzene, yielded monometallic or bimetallic azodioxide complex salts of the form [M(az)₄](PF₆)₂, [M(bpy)₂(az)](PF₆)₂, and [{M(bpy)(az)(μ-Cl)}₂](PF₆)₂ (az = cis-N,N′-diphenylazodioxide), which have been structurally characterized via single-crystal X-ray diffraction. The method of activation of chloride salts or chlorido complexes by chloride abstraction with Tl⁺, followed by the addition of nitrosobenzene, continues to be an effective strategy for the synthesis of azodioxide complexes, and it has enabled the synthesis of the first structurally characterized azodioxide complexes of any metals of Groups 7, 10, or 11.

The coordination ability of Ag₂[B₁₂Cl₁₂] in the presence of S-containing ligands (tetrahydrothiophene, tetramethylthiourea, 1,3-diisopropyl-2-thiourea, 1,3-dithiole-2-thione) was studied. Mononuclear silver(I) complexes [Ag(L₁)₄]₂[B₁₂Cl₁₂] (L₁ is tetrahydrothiophene) and [Ag(L₂)₃]₂[B₁₂Cl₁₂] (L₂ is tetramethylthiourea) as well as binuclear silver(I) complexes [Ag₂(L_x)₆][B₁₂Cl₁₂] (x = 3, 4; L₃ is 1,3-diisopropyl-2-thiourea, L₄ = 1,3-dithiole-2-thione) were isolated and studied by NMR, IR spectroscopy and single-crystal X-ray diffraction. In all complexes isolated, the perhalogenated boron cluster [B₁₂Cl₁₂]^2– plays the role of a counterion.

This work describes the synthesis, characterization, crystal structure, and computational analyses of the zinc porphyrin [ZnT(4-Cl)PP], 1 and its pyrazine bound analogue, [ZnT(4-Cl)PP(pyz)], 2, (where T(4-Cl)PP stands for 5,10,15,20-tetrakis-(4-chlorophenyl)porphyrin and pyz represents pyrazine). Both compounds were structurally characterized by UV–visible spectroscopy, infrared spectroscopy, ¹HNMR spectroscopy, ¹³CNMR spectroscopy and single crystal XRD. The crystal structure of the 2 consists of a zinc porphyrin with an axial pyrazine ligand forming a penta-coordinated complex with Zn1-N5(pyz) distance 2.228(3) Å. To investigate the key insights into their photophysical properties, fluorescence emission spectral analysis of the synthesized compounds has been studied. Theoretical calculations like optimization of geometry, the energy of frontier orbitals, Hirshfeld surface analysis and simulation of electronic spectra were performed which supports the experimental results.

This study involves designing through DFT, synthesis, and characterization of three benzimidazolium salts (AL1-AL3) and their corresponding selenium adducts (AC1-AC3). The compounds were characterized theoretically as well as experimentally through FT-IR and ¹H & ¹³C NMR. Theoretical calculations were performed using the B3LYP/6–31 G (d, p) levels of theory to determine various optical and chemical properties of the designed molecules. The HOMO/LUMO energies and their energy gaps were also calculated to assess the structure–activity relationships. In vitro testing against the Human breast Adenocarcinoma cell line (MCF-7) was conducted using the MTT assay and 5-Fluorouracil (standard) was used for the comparison of results. The ligand AL3 showed maximum inhibitory potential (66.51 ± 0.82) even approaching the standard 5FU while the complex AC3 showed maximum viability with the least inhibition value as (21.7 ± 0.73) against MCF7 cell line. The antioxidant potential for scavenging DPPH radicals was also assessed, revealing that AL1 has the greatest potential, with a value of 62.01 ± 0.9. The interactions of the complexes with various proteins were also assessed via molecular docking studies, revealing strong binding energies and ligand affinities towards angiogenic factors such as VEGF-A, EGF, HIF, and COX-1. This suggests that the anticancer activities of the complexes AC1-AC3 may be attributed to their potent anti-angiogenic effects. Moreover, selenium-NHC adducts exhibited more significant anticancer potential as compared to their ligands. Furthermore, the antibacterial and antifungal potential of compounds AC1-AC3 was assessed. Notably, the ligand AL2 exhibited significant antibacterial activity against E. coli, as evidenced by a zone of inhibition (ZI) value of 17.5 ± 0.29 mm, whereas AL3 demonstrated the highest activity against P. multocida showing the ZOI value of 18.5 ± 0.38. Among all the synthesized compounds, AL1 displayed the most significant antifungal activity against F. avenaceum (27 ± 0.51 mm), surpassing even the standard drug gentamycin (13 ± 0.23 mm), which was tested under the same conditions. However, its corresponding Se-NHC, AC1, adduct was found to be inactive. Overall, AL3 and its corresponding Se-NHC adduct (AC3), demonstrated superior biological potential against the majority of the tested strains.