Journal of Organometallic Chemistry最新文献

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.

An admirable catalytic activity of as-prepared copper oxide decorated reduced graphene oxide nanocomposite (rGO/CuO NC) catalyst is reported in the synthesis of spiro[indoline-pyranothiazole]carbonitrile and thiazolopyranofuroindole derivatives. The excellent activity exhibited by hybrid nanocomposite is attributed to the synergistic effect of graphene oxide and copper oxide nanoparticles. The utilization of ultrasonication as energy source lead to enhanced mass transfer, and reaction rate expeditiousness in the presence of rGO/CuO NC forming spiro/condensed indole derivatives. 100% conversion is observed on Thin Layer Chromatography (TLC). The recovered rGO/CuO NC can be reused for four uninterrupted cycles without substantial loss in its catalytic activity. DFT (Density functional theory) studies, Mulliken atomic charge analysis and anti-inflammatory activity of the synthesized spiro/condensed indole derivatives have also been evaluated.

A tri-imidazolium salt LH₃·(PF₆)₃ and its NHC (N-heterocyclic carbene) Ag(I) complex 1 were prepared and characterized. The structures of LH₃·(PF₆)₃ and 1 were demonstrated by X-ray diffraction analysis. In LH₃·(PF₆)₃, two imidazoles lied on the same side of triazinetrione plane, and the third imidazole lied on another side of triazinetrione plane. Complex 1 was of a scorpion-like structure with a 12-membered macrometallocycle. Additionally, the selective recognition of 1 for H₂PO₄^- was studied on the basis of fluorescent spectra, ¹H NMR, MS and IR. The high association constant for 1·H₂PO₄^- (K = 3.3 × 10⁴ M^-1) showed that 1 had strong association ability to H₂PO₄^-. The low detection limit (2.54 × 10^-10 mol/L) indicated that the detection of 1 to H₂PO₄^- was sensitive.

We carried out this research was in order to evaluate the potency of guar gum (GG) hydrogel to conduct CuO NPs synthesis by adopting an eco-friendly approach as well as to study its role as catalyst and in relieving cancerous cell lines. In this context, we accomplished the CuO NPs/GG synthesis by employing a simple one-step approach and identified its characters through UV–Visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), transmission electronic microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDS), elemental mapping and ICP-OES analysis. XRD and TEM results of CuO NPs/GG showed the face centered cubic (fcc) structures and predominantly spherical shaped with a size of 20–30 nm. After the characterization, the prepared CuO NPs/GG nanocatalyst was used as catalyst in the N-arylation of amines (indole and imidazoles) through C(aryl)-N chemical bond arrangement from the related aryl halides (I, Br, Cl) by Ullmann-type coupling reactions. It is worth mentioning that the novel catalyst has the potential of being recycled seven times without much change in activity. Furthermore, the anti-kidney cancer properties of CuO NPs/GG nanocomposite were assessed by MTT assay about the cytotoxicity and anti-human on normal (HUVEC) and human kidney cell lines i.e. ACHN, CaKi-2 and HEC293. The corresponding IC₅₀ values were 18.5, 17.2, and 15.6 µg/mL, respectively. The viability of malignant human kidney cell line reduced dose-dependently in the presence of the nano bio-composite. After clinical study, CuO NPs/GG nano bio-composite can be utilized as an efficient drug in the treatment of human kidney cancer in human.

A series of stable mononuclear half-sandwich iridium(III) complexes of the general formula [(η⁵-C₅Me₅)Ir(L)Cl](BPh₄) has been synthesized in dry methanol using different imino pyridine ligands (L₁–L₆) and [(η⁵-C₅Me₅)₂Ir₂(µ-Cl)₂Cl₂] in a 2:1 molar ratio. All complexes were fully characterized by melting point, CHN analysis, FT-IR, UV–visible, ¹H NMR, ¹³C NMR spectroscopy and mass spectrometry. The structure of complex 3 [(η⁵-C₅Me₅)Ir(L₃)Cl](BPh₄) was determined by single crystal X-ray structure analysis, showing a chelating coordination mode of the imino pyridine L₃. One pot organic transformations of aldehyde to amide were carried out by complexes 1–6 in toluene at 110 °C in the presence of hydroxyl amine hydrochloride and sodium bicarbonate. The catalytic activity of complex 3 was found to be excellent, showing high conversion with catalytic turnover frequency up to 500.

Ln (Ln = La and Ce) atom reactions with ethylamine are conducted in a pulsed laser vaporization supersonic molecular beam source. Dehydrogenation and association metal-containing species are observed with time-of-flight mass spectrometry, and the dehydrogenated Ln ethylimido species in the formula Ln(NC₂H₅) are characterized by single-photon mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and a scalar relativity correction, electron correlation, and spin-orbit coupling through multiconfiguration quasi-degenerate second-order perturbation theory for the Ce species. The MATI spectrum of lanthanum ethylimido La(NCH₂CH₃) has a single vibronic band system from the ionization of the doublet ground state with the La 6s¹ configuration, whereas that of the cerium ethylimido Ce(NCH₂CH₃) displays two vibronic band system from the ionization of the two lowest-energy spin-orbit coupling states with the Ce 4f¹6s¹ configuration. Both Ln ethylimido complexes are formed by the thermodynamically and kinetically favorable concerted dehydrogenation of the amino group. Two additional isomers of Ln(NC₂H₅) include a four-membered metallacycle Ln(NHCH₂CH₂) from the dehydrogenation of the amino and methyl groups and a three-membered cycle Ln(NHCHCH₃) from the dehydrogenation of the amino and methylene groups. The cyclic isomers are not observed experimentally as they are not populated under the experimental conditions.

Telluropyran and telluropyrylium derivatives are organotellurium compounds featuring a tellurium atom integrated into a pyran or pyrylium ring system. These compounds are of interest due to their unique electronic properties and potential applications in various fields such as materials science, catalysis, and medicine.

When benzene, indene and/or thiophene are fused with the b edge of 4H-telluropyran, four distinct condensed telluropyrans structures can be identified. These include 7H-telluropyrano[3,2-b]thiophene, 4H-tellurochromene, 9H-telluroxanthene and 9-dihydroindeno[2,1-b]telluropyran and 9H-tellurochromeno-[3,2-b]thiophene. The synthesis of telluropyran derivatives is achievable through various chemical pathways, encompassing Suzuki coupling reactions, Stille coupling reactions, and Sonogashira coupling reactions.

Hydrogen transfer reduction methods are attracting increasing attention from synthetic chemists in view of their operational simplicity. Therefore, the novel Ni(II) and Fe(II) tetra substituted metallophthalocyanines containing resorcinol and guaiacol groups were synthesized using microwave irradiation and characterized via elemental analysis, UV-Vis and FT-IR spectroscopy, and TGA. The comparison of the catalytic features of phthalocyanine based on metals is discussed in detail. These phthalocyanine-complexes were tested in transfer hydrogenation (TH) of ketones in the existence of KOH, utilizing 2-propanol as a hydrogen source. Examination of different carbonyl substrates revealed that Nickel (II) phthalocyanine, (Ni2) complex was a remarkable catalyst for the catalytic reduction of acetophenones (1.0 mol % of catalyst, 99 % conversion). Furthermore, we have discovered that the catalytic characteristics of this class of molecules are significantly influenced by both steric and electronic variables.

Controlling the site-selectivity in the C-H functionalization of anilines is one of the great challenges in synthetic chemistry. Considering the numerous applications of aniline derivatives in pharmaceuticals, agrochemicals and advanced materials, the para-selective functionalization of these scaffolds has received much attention. Various synthetic methods on the para-selective functionalization of primary, secondary and tertiary anilines, including electrophilic aromatic reactions, nucleophilic aromatic reactions, oxidative addition, radical addition, and carbenoid addition are highlighted in this review.