European Journal of Inorganic Chemistry最新文献

While the collision-induced dissociation (CID) of the mass-selected cation [(Ph₃P)₂Pt(CH₂SCH₃)]⁺ causes the selective liberation of PPh₃, the diphosphine complex [(dppe)Pt(CH₂SCH₃)]⁺ (dppe=1,2-bis(diphenylphosphino)ethane) ejects C₂H₄, CH₂S, and (CH₃)₂S upon CID. The analogous palladium complexes [(Ph₃P)₂Pd(CH₂SCH₃)]⁺ and [(dppe)Pd(CH₂SCH₃)]⁺ show similar reactivity, except that C−H-bond activation is completely lacking. For other bidentate diphosphine ligands such as dppm, dppv, dppp, dppb, dppbz, dppf, and xantphos, a correlation of the dominant reaction channels with the bite angle is observed. For bite angles > 90°, hydrogen-atom transfer is favored, as evidenced by an increase in dimethyl-sulfide loss. For smaller bite angles (< 90°), intramolecular activation of the thiomethoxymethyl ligand predominates, thus resulting in increased losses of thioformaldehyde and ethene. The results of the CID experiments are compared with those for [(bipy)Pt(CH₂SCH₃)]⁺, for which the loss of C₂H₄ is observed as the main process. DFT calculations for the complexes [(dppe)Pt(CH₂SCH₃)]⁺ and [(bipy)Pt(CH₂SCH₃)]⁺ together with the experimental findings uncover subtle differences in the underlying reaction mechanisms.

To develop proton exchange membranes (PEMs) with robust structure stability and remarkable proton conductivity and explore their application in PEMs fuel cells have significant implications for realizing reduced carbon emission and environmental pollution. Covalent organic frameworks (COFs), as crystalline porous polymer material composed of organic monomers and connected by covalent bond, possess specific framework, inherent porosity, adjustable functional group and eminent thermal/chemical structure stability. Therefore, COFs display prominent superiorities in constructing rigid ordered proton transfer channels and improving fuel cell performance long-term durability. In this review, the proton conduction properties of extrinsic proton-conductive COFs (incorporating carriers into the pore), intrinsic proton-conductive COFs (introducing conductive groups on the backbone) and combined extrinsic/intrinsic proton-conductive COFs in the form of pressed pellets are discussed in detail. Meanwhile, proton-conductive COFs related PEMs, including COFs-related polymer-based composite membranes, COFs-based composite membranes and self-supporting COFs membranes are also systematically summarized. In addition, the existing challenges are analyzed and future outlooks are addressed.

Novel electrode materials with unique architectures are always favored to improve the capacity and energy density of supercapacitors. Herein, we have designed a composition of transition metal and reduced graphene oxide (rGO) as advanced electrode for enhanced-performance supercapacitors. Particularly, a facile one-pot hydrothermal approach was applied for in-situ growth of NiCo/rGO composite. It displayed the best electrochemical performance attributing to the three-dimensional flower-like architecture in combination with conductive rGO. Among all the electrodes, NiCo/rGO exhibited impressive areal capacitance of 2565 mF/cm² at a current density of 1 mA/cm², and a high energy density of μWh/cm² at a power density of 200 μW/cm². The electrochemical impedance spectroscopy confirms feasible charge transfer kinetics at the interface with small internal resistance and rapid diffusion, resulting an improved electrochemical performance.

Extraction of uranium from seawater is considered to be an effective way to solve the shortage of uranium resources, and the development of efficient adsorption functional groups is the key to uranium extraction. In this work, the complexation of uranyl cations with a series of diamidoxime and bifunctional (amidoximate-carboxylate, amidoximate-phosphate) ligands has been probed by quantum chemical calculations. For most of the uranyl complexes, the amidoxime groups adopt η² mode to uranyl cations. Based on bonding analyses, we found that the uranyl complexes with methyl-substituted ligands (H₂L′) possess stronger covalent interactions than those with phenyl-substituted ligands (H₂L). Consequently, the uranyl complexes with H₂L’ are more stable in the extraction process according to thermodynamic analysis. The amidoximate-phosphate bifunctional ligand (H₂L₃′) has stronger extraction capacity to uranyl cations than other ligands, which is related to the relatively lower decomposition energy, and it shows selectivity in seawater for uranyl cations over vanadium ions, which may be a potential ligand for uranium extraction. Therefore, the introduction of synergistic functional groups, i. e. the bifunctional ligands, enhance the extraction properties of uranyl cations. This work improves understanding of synergistic ligands, and may contribute to design and development of efficient ligands for recovery of uranium from seawater.

Pyrene-functionalized silicon hybrid porous polymer (TAPPy-HPP). The hybrid polymer was successfully prepared via a Schiff base reaction using tetra(4-aminophenyl)pyrene (TAPPy) and tetra(4-formylphenyl)silane (TFS) as the building blocks.. This hybrid polymer was characterized using IR, solid-state ¹³C and ²⁹Si NMR, and elemental analysis. Its morphology was analyzed by PXRD and SEM. Thermal analysis using Thermal analysis using TGA shows that the synthetic polymer has greater thermal stability than its monomers at a temperature of 5 % weight loss (T_d5 %) of 392 °C. Although TAPPy-HPP has a Brunauer-Emmet-Teller surface area of 45.4 m² g⁻¹, it adsorbed dyes with high efficiency, particularly the anionic dye Congo Red (CR), with an adsorption capacity of up to 358 m² g⁻¹. Moreover, TAPPy-HPP showed excellent recycling and regenerative properties. This polymer is a promising candidate for a fluorescent chemical sensor for the absorption of dyes due to its exceptional physiochemical stability and intense luminescence.

A water-soluble copper catalyst (NH₄)₈[Cu₂(H₂O)₈W₁₂O₄₂] ⋅ 4H₂O is prepared by the generated paratunngstate B in situ, which can catalyze the H₂O₂ oxidation of cyclohexanol to cyclohexanone with a yield above 98 % in water under much milder conditions of 35 °C and atmospheric pressure, and the substrate can be extend to other secondary alcohols, potentially leading to an economical, green, and efficient ketone production method for industrial use.

A series of six disubstituted diacylthioureas 1,3- and 1,4-C₆H₄[C(O)NHC(S)NR¹R²]₂ (L^1–6) were synthesized with varied Rⁿ substituents (R¹=R²=Et for L^1,2; R¹=R²=Bn for L^3,4; R¹=iPr and R²=Ph for L⁵ (1) and L⁶ (2)). Treatment of Lⁿ with Cu(I) halide precursors CuX(PPh₃)₃ (X=Cl, Br, I) produced the discrete binuclear adducts Lⁿ[CuX(PPh₃)₂]₂ (3–11 and 14–16; n=1–3 and 6) by binding to Cu(I) centres via the monodentate-S mode. In contrast, L⁴ and L⁵ yielded only the chloride products of binuclear L⁴[CuCl(PPh₃)₂]₂ (12) and mononuclear L⁵CuCl(PPh₃)₂ (13), respectively, with one S arm in the latter remaining dangling, while bromide or iodide analogues were not available for L⁴ and L⁵, possibly due to the steric hindrance imposed by larger halide anions or bulky isopropyl substituents. The reactions of Lⁿ with nitrate [Cu(NO₃)(PPh₃)₂] led to the double-deprotonation of ligand protons to generate dianions Lⁿ′ (1,3-/1,4-C₆H₄[C(O)NC(S)NR¹R²]₂²⁻) and led to the consequent formation of binuclear diacylthioureato Cu(I) complexes Lⁿ′[Cu(PPh₃)₂]₂ (n=1 (17), 2 (18), 4 (19)) via the κ-O,S-bidentate mode. The obtained ligands and complexes were spectroscopically and structurally characterized. These Cu(I) products (3–19) were experimentally used as catalysts for the oxidation of 1-phenylethanol.

A ruthenium(II) aquo complex [Ru(dipic)(PPh₃)₂(OH₂)], (1 A), bearing O,N,O-coordinated 2,6-dipicolinate was synthesized via reaction of [Ru(PPh₃)₃Cl₂] with 2,6-dipicolinic acid. Crystal structure of 1 A was determined. Utilizing 1 A as a synthon, three new complexes were synthesized. Reaction of 1 A with a bidentate NHC-ligand, viz. 1-methyl-3-(2′-pyridyl)imidazole (IMe^CN), afforded [Ru(dipic)(IMe^CN)(PPh₃)], (2 A). Similar reactions of 1 A with two pincer ligands, viz. 2,6-bis(1′-methyl imidazolyl)pyridine (IMe^CNC) and 2,2′;6′,2“-terpyridine (trpy), respectively yielded [Ru(dipic)(IMe^CNC)(PPh₃)], (3 A) and [Ru(dipic)(trpy)(PPh₃)], (3 B). Structure of 2 A was optimized by DFT method. Structures of 3 A and 3 B were determined by X-ray crystallography. In both 3 A and 3B the 2,6-dipicolinate ligand was found to be N,O-coordinated with one carboxy end remaining unbound to the metal center. Anticancer property of 2 A, 3 A and 3 B was studied and compared. Cytotoxicity of 3 A, studied against three selected cancer cell lines, viz. chronic myelogenous leukemia cell line (K562), hepatocellular carcinoma cell line (HepG2) and breast adenocarcinoma cell line (MCF7), was found to be the most promising. It displayed the best activity against K562, while it did not have any appreciable effect on its normal counterpart, viz. the human peripheral blood mononuclear cells (hPBMC). The comparative cytotoxicity studies indicated that presence of the C,N,C-coordinated pincer NHC ligand in 3 A, together with presence of the free carboxylate end of N,O-coordinated dipic ligand, are presumably responsible for its superior cytotoxic behavior.

The photoirradiation to the Zn complex crystal having N-(4-pyridylmethylene)aniline (4-pma) ligand with a central –C=N- bond led to no photodimerization reaction but only partial trans-cis isomerization of 4-pma. The reason why no photodimerization reaction occurred may be due to the stable twisted structure of 4-pma causing the prevention from proper approaching of neighboring 4-pma ligands.

CO₂ capture technology has been widely used to reduce CO₂ emissions, resulting in a variety of capture methods and materials. Among them, the more widely used is the chemical absorption method. However, the chemical absorption method has problems such as high energy consumption and slow absorption rate. In order to solve the above problems, we prepared an effective catalyst to improve the CO₂ absorption rate. ZIF-8 and hydrophilic ZIF-8-DA were prepared by in situ synthesis under ambient conditions. The catalytic effect of the hydration reaction of ZIF-8 and ZIF-8-DA was tested using CO₂ absorption regeneration experiments under aqueous and alkaline conditions, respectively. The results showed that the synthesized catalysts could significantly enhance the CO₂ absorption in water and alkaline solution. The addition of 0.1 wt % of ZIF-8 in alkaline solution increased the average CO₂ absorption by 1.80–15.84 %, respectively, while the addition of 0.1 wt % of ZIF-8-DA increased the CO₂ absorption by 7.01–25.36 %. In addition, both catalysts had excellent reusability and maintained high performance even after five absorption and regeneration cycles. Polymer dispersibility index (PDI) results showed that ZIF-8-DA dispersed more uniformly in aqueous solution.