Journal of Organometallic Chemistry最新文献

A kind of magnetic hybrid organic-inorganic nanoparticles containing Ru metal (Fe₃O₄@SiO₂-FPBA-Ru) was prepared. It was spherical with the characteristic lattice fringe of ruthenium atom. The size was in the range of 5–15 nm and it contained 0.30 mmol/g Ru. Its saturation magnetization value was 15.95 emu/g, which could be easily and efficiently recovered from solution through an external magnet. It was also stable below 240°C and hot filtration experiment proved Ru wasn't leaked from Fe₃O₄@SiO₂-FPBA-Ru in 70°C oxidation reaction. It could be recovered and reused at least 7 cycles. The low amount of Fe₃O₄@SiO₂-FPBA-Ru (75 mmol%) could convert the 99 % of 1-phenylethanol to acetophenone under solvent-free system, which verified its green and environment-friendly properties. The yield was exceed that of homogeneous (RuCl₃, 85 %). Beside this, the TON (5181), TOF (7430 h⁻¹) in oxidation of 1-phenylethanol and high conversion yields for a series of oxidation reactions of aromatic secondary alcohols proved the high catalytic ability of Fe₃O₄@SiO₂-FPBA-Ru. These laid a foundation for its industrial applications.

The current study highlights on the synthesis and characterization of aqua-complexes of the fac-[M(CO)₃]⁺ (M = Re and ^99mTc) core with pyrimidine-4,6-dicarboxylic acid (H₂pmdc) and its monoester 6-(ethoxycarbonyl)pyrimidine-4-carboxylic acid (Hetpmdc), which are the model for future design of imaging and therapeutic radiopharmaceuticals. Complexes [M(CO)₃(OH₂)(Hpmdc)] (M = Re (1) and ^99mTc (2)) were formed from the reaction of H₂pmdc with [Re(CO)₅Br] in water and aqueous solution of [^99mTc(CO)₃(OH₂)₃]⁺ respectively. The reaction of [Re(CO)₅Br] with H₂pmdc in ethanol (EtOH) has also studied and led to the complex [Re(CO)₃(OH₂)(etpmdc)] (3), where etpmdc⁻is 6-(ethoxycarbonyl)pyrimidine-4-carboxylate anion which was formed from the mono-esterification of H₂pmdc in parallel with its coordination to the fac-[Re(CO)₃]⁺ unit. The complex [^99mTc(CO)₃(OH₂)(etpmdc)] (4) was formed in parallel with 2 by reacting H₂pmdc with aqueous solution of [^99mTc(CO)₃(OH₂)₃]⁺ and ethanol. The chemical identification of 1 and 3 was achieved by using ¹H NMR, ¹³C NMR, IR, ESI-MS and elemental analysis. Complex 3 was furtherly identified by using single crystal X-ray crystallography. The structural similarities of 1 and 2 was assessed by coinjection of both complexes in the HPLC with UV/Vis detection coupled with a γ-detector followed by comparison of retention times of the γ-peak of 2 and the UV-peak of 1 which allowed unambiguous identification of 2. Similarly, the formation of complex [^99mTc(CO)₃(OH₂)(etpmdc)] (4) in parallel with 2 was assessed by coinjection of complexes 1 and 3 with the product from the reaction of H₂pmdc with aqueous solution of [^99mTc(CO)₃(OH₂)₃]⁺ and ethanol in the same HPLC as one used for the structural identification of 2 followed by comparison of retention times of the γ-peaks of 2 and 4 and the UV-peaks of 1 and 3.

We present the synthesis and structural characterization of a novel dimeric sodium complex with the chemical composition [{Ph₂Si(H)PhN}Na(THF)₂]₂ (Na-1) supported by N,1,1-triphenylsilanamine fragment. The single-crystal X-ray diffraction analysis of complex Na-1 in the solid state reveals the coordination of sodium ion with N and O atoms of the triphenylsilanamine unit, forming a four-membered ring. The sodium complex also demonstrates excellent activity as a pre-catalyst towards the cyanosilylation of a wide array of ketones with trimethylsilyl cyanide (TMSCN) to afford trimethylsilyloxypropanenitriles in excellent yield (up to 99 %) in a shorter time under mild and solvent-free reaction conditions and exhibits a greater tolerance to a variety of ketones bearing electron-withdrawing and electron-donating functional groups. The plausible mechanism of cyanosilylation of ketones catalyzed by the complex Na-1 is also proposed.

In the present work, Ni-Fe₂O₃@SiO₂-Pr-DBU was synthesized as a novel magnetically separable nano-catalyst and characterized by various techniques like Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Vibrating-sample magnetometry (VSM), Transmission electron microscopy (TEM) and Elemental analysis by energy dispersive X-ray (EDX). The catalytic efficiency of NiFe₂O₃@SiO₂-Pr-DBU was explored in the synthesis of dihydropyrano[3,2-c] chromenes through a one-pot multicomponent reaction of 4-hydroxycoumarin, malononitrile, and aryl aldehydes in aqueous solution at ambient temperature condition. An external magnet easily removed the nano-sized magnetic core catalyst from the synthesized reaction mixture. It was recycled for five successive runs while maintaining its potential and adhering to our green synthesis approach. We used dihydropyrano chromene, a highly biologically active commercial compound, to prepare some novel derivatives.

In this study, Fe₃O₄ was modified with a biocompatible carbohydrate D-(+)-ribonic γ-lactone (RL) followed by immobilization with CuO nanoparticles (CuO NPs) to produce Fe₃O₄-APTES-RL-CuO as a Lewis acid catalyst. The sustainable RL can be utilized as a novel support for CuO NPs with increased catalytic activity. RL with plenty of hydroxyl groups not only catch the CuO NPs and prevents them from agglomeration but also, prevails upon immobilization of CuO NPs making the nanohybrid RL-supported CuO NPs significantly stable. This green and effective heterogeneous catalyst can be used for one-pot ultrasound-assisted synthesis of 1,4-dihydropyridines (1,4-DHPs) with high yield (95٪) and short time (15 min). The catalyst can be separated easily and cleanly by using an external magnet. This nanomagnetic catalyst is reused five times without any remarkable reduction in its activity. To illustrate the structure of the catalyst and characterize its physicochemical properties, different techniques like FT-IR, XRD, FE-SEM, EDS, TGA, and VSM were applied.

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.