Journal of Organometallic Chemistry最新文献

Undoubtedly, pyrimidine and selenophene stand as invaluable heterocyclic compounds pivotal in the quest for novel drug development. The fusion of selenophene and pyrimidine motifs into hybrid architectures has ushered in a realm of promising pharmacological potentialities. This amalgamation has given rise to selenophenopyrimidine derivatives, such as selenopheno[2,3-d]pyrimidine, selenopheno[3,4-d]pyrimidine, and selenopheno[3,2-d]pyrimidine, each boasting intriguing properties. Synthesizing selenophenopyrimidines encompasses diverse chemical pathways, including one-pot multi-component reactions, Vilsmeier-Haack reactions, Gewald reactions, and Suzuki cross-coupling methodologies.

A new series of heterobimetallic complexes of the type [Cu(L)(PPh₃)₂]X (1–4) [where L = trans-4-(ferrocenylideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one; PPh₃ = triphenylphosphine, X = NO₃⁻(1), ClO₄⁻ (2), BF₄⁻ (3) , PF₆⁻ (4)] were prepared by reaction of L with [Cu(MeCN)₂(PPh₃)₂]X and characterized by elemental analysis, FTIR, ¹H NMR, ³¹P NMR and UV–visible spectral studies. The thermal stability of (1–4) has been investigated by using thermogravimetric analysis (TGA). X-ray powder diffraction of the representative complex 1 used to clarify the crystal structure of the complex. The electrochemical behaviour of complexes (1–4) displayed quasireversible redox behaviour corresponding to Cu(I)/Cu(II) and Fe(II)/Fe(III) couples. All complexes show red emission as a result of ligand-ligand charge transfer (LLCT) and metal-ligand charge transfer (MLCT) or admixture of them. The catalytic efficiency of the complexes (1–4) was tested and it was found that the complex 4 worked as an effective catalyst for the C-N coupling reaction of aromatic amines and aryl halides.

In the present work, Cu‐Ni mixed nanoparticles immobilized in magnetic clay (MMT-BAC@Fe₃O₄@CuNi) nanocatalyst were successfully synthesized using a simple method for the first time. In the design of this catalyst, nickel and copper ions were reduced and deposited on clay layers using a benzalkonium chloride directing group. The proposed method offers a safe, sustainable, and selective approach for the synthesis of 2-substituted benzimidazole and 3,4-dihydropyrimidin-2(1H)-ones using an environmentally friendly nanocatalyst. The solid catalyst was distinguished using a diversity of methods, including EDX (Energy Dispersive X-Ray), XRD (X-ray Diffraction), ICP (Inductively Coupled Plasma), VSM (Vibrating Sample Magnetometer), FT-IR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy) and FE-SEM (Field Emission Scanning Electron Microscopy). The significant features of this new protocol include good to excellent efficiency, oxidant-free conditions, low catalyst loading, inexpensive and non-toxic catalyst, simple procedure, moderate conditions, straightforward work-up, short reaction times, and easy reuse of the nanocatalyst.

Phosphorescent transition metal complexes are considered as promising probes for oxygen sensing in living cells and tissues. Red light-emitting complexes are more valuable because the red irradiation better penetrates into biological tissues. In the present study, far-red light-emitting iridium(III) complexes PnIr1-PnIr4 on polyoxanorbornene platform were synthesized and their oxygen sensing properties were tested in water and in cells in vitro. Iridium(III) complexes incorporated into polymeric platform contained 1-(thien-2-yl)isoquinoline cyclometalating ligands and norbornene-substituted picolinate (PnIr1) and diimine (PnIr2-PnIr4) ancillary ligands. The quantum yields and phosphorescence lifetimes of the synthesized polymeric iridium probes in degassed water solutions were 1.5–2 times higher than in aerated solutions demonstrating oxygen-dependent quenching of phosphorescence. Of the four probes, PnIr1 easily penetrated into cultured cancer cells grown as monolayer and 3D spheroids and showed reliable response to hypoxia with increase of lifetime from 1.31 to 3.06 µs. Good water solubility, far-red oxygen-sensitive emission and low cytotoxicity make the new probe a promising tool for intracellular oxygen assessments in cancer research.

Cu(dmamp')₂ (1) (dmamp' = 2-(dimethylamino)-2-methyl-1-propoxide) was synthesized for comparison according to the position of the substituent of aminoalkoxide. When comparing the properties such as structure, thermal stability, and usability with 1 and the previously reported Cu(dmamp)₂ (dmamp = 1-dimethylamino-2-methyl-2-propoxide), other properties were similar, but 1 had better thermal stability. Consequently, 1 is thought to be a better precursor for thin films and nanomaterials containing Cu.

Five NNN type pincer-metal complexes NNN-CuCl₂ (6a), (R,R)-NNN-CuCl₂ (6b), NNN-NiCl₂⋅H₂O (6c), (R,R)-NNN-NiCl₂⋅H₂O (6d), and (R,R)-NNN-CoCl₂ (6e) were synthesized in reasonable yield and characterized by HRMS, and/or single crystal X-ray diffractions. The ORTEP drawing of complexes 6b, 6e shows that the coordination geometry around the metal center is approximately square pyramidal. The cytotoxicities of these compounds were evaluated in vitro against K562, 293T, MCF-7, SiHa, and SH-SY5Y cell lines. The pharmacological results showed that most of the prepared compounds displayed good selective cytotoxicity toward K562 cells. Among them, compounds 6a and 6b possessed good anticancer activity against all cancer cells with less cell toxicity on 293T cells, even superior to cisplatin.

A method has been developed to prepare previously inaccessible substituted 1,3-benzotellurazoles following an efficient two-step process, consisting of the tellurination of electron rich phenyl ureas with tellurium tetrachloride and subsequent ring closure of the resulting aryl tellurium trichlorides. Tellurination occurs regiospecifically ortho to the urea moiety due to intramolecular Te–O coordination, producing highly crystalline solids that are readily isolated in yields up to 83 %. Subsequent ring closure, accomplished by heating with phosphorus trichloride and subsequent reduction with hydrazine hydrate, provides access to 1,3-benzotellurazole derivatives. Selected products were characterized by X-ray crystallography.

A new 1,10-phenanthroline-functionalized MCM-41-immobilized copper(I) complex [MCM-41-Phen-CuCl] was prepared from 1-(1,10-phenanthrolin-5-yl)-3-(3-(triethoxysilyl)propyl)urea via immobilization on MCM-41, followed by reacting with copper(I) chloride. It was found that this heterogenized copper(I) complex is a highly efficient catalyst for the oxidation of a wide variety of alcohols into aldehydes and ketones using molecular oxygen as the stoichiometric oxidant and 5 mol% of di-tert-butyl hydrazine-1,2-dicarboxylate (DBAD-H₂) as additive, and can be recycled more than eight cycles with almost consistent activity.

This study investigated the catalytic activity of the magnetic Fe₃O₄@Bio-R-Pd (Bio = biochar, R = epichlorohydrin and guanidine) for the reduction of nitro compounds. The structural and magnetic properties of the synthesized nanocatalyst were characterized using a suite of techniques including inductively coupled plasma spectrometry (ICP), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier Transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). The recyclability of the synthesized nanocatalyst was confirmed by its complete reversibility upon testing with a vibrating magnetometer, further supporting its paramagnetic nature. Analysis of the SEM images revealed the presence of spherical magnetite particles within the composite. Using these optimized conditions, various aromatic nitro compounds were successfully reduced in the presence of the Fe₃O₄@Bio-R-Pd catalyst. The results demonstrate the advantageous properties of the synthesized nanocatalyst, including high product yield, stability and resistance at high temperatures, easy separation from the reaction medium, high efficiency with short reaction times, and economic viability. Notably, the synthesized sample exhibited nearly the same initial efficiency after 5 reuses, indicating almost complete recovery and minimal change in its catalytic activity.

An overview of bis(trialkylsilyl) polyynediyl adducts R₃Si(CC)_nSiR₃ with n ≥ 5 is followed by syntheses of TESC_xTES where x = 8, 12, 16, and 24 (TES = SiEt₃; x = 2n). In a seminal 1972 study, the last three were presented as too unstable to isolate and thus only characterized by UV-visible spectroscopy. Although not a rational route, TESC₂₄TES is consistently obtained from the reaction of trans-(C₆F₅)(p-tol₃P)₂Pt(CC)₅SiEt₃ and crude HC₈TES under Hay oxidative cross coupling conditions. The latter contains some HC₈H and TESC₈TES. Hay oxidative homocouplings of HC₄TES and crude HC₈TES afford TESC₈TES (83%) and TESC₁₆TES (5%). A Cadiot-Chodkiewicz reaction of BrC₄Br and HC₄TES (2 equiv) yields TESC₁₂TES (11%). All of these compounds are crystalline, and the crystal structures of TESC₈TES and TESC₁₆TES are determined. The ¹³C{¹H} NMR and UV-visible properties are also compared.