Inorganic Chemistry最新文献

Sodium dehydroacetate (Na-DHA) is widely employed asa food preservative;excessive intake poses potential risks to human health, and the accuratedetection of Na-DHA in food is very important. Herein, we developa dual-emission Tb-MOF and its rhodamine B (RhB)-encapsulatedderivative (Tb-MOF@RhB) with triple-emission properties,which achieves the ratiometric fluorescence sensing of Na-DHA. Tb-MOF enables highly selective and sensitive ratiometricfluorescence detection of Na-DHA with a low limit of detection (LOD= 3.64 μM) and satisfactory recoveries (96.12–106.71%)in food samples. Taking advantage of hydrogen-bonding interactionswith Na-DHA, Tb-MOF@RhB displays a distinct ratiometricand colorimetric fluorescence response via three emission channels,accompanied by a visible color change from yellow to green, with LODsof 2.20 μM (I₅₄₆/I₄₃₉) and 6.17 μM (I₅₈₅/I₄₃₉). Moreover, Tb-MOF@RhB can also enable quantitative detection of Na-DHA in food sampleswith high recoveries of 95.10–105.45%. Furthermore, portablesmartphone-assisted detection platforms were developed to facilitatehigh-precision on-site sensing of Na-DHA.

A number of Pd(II)- and Pt(II)-diimine complexes weresynthesizedby reacting [Pd(bpy)Cl₂], [M(phen)Cl₂] (M =Pd, Pt), and [Pd(phenpz)Cl₂] with dithiocarbamates (L1and L2). Complexes 1, 3a, and 3b show respective intramolecular Pd(II)···Pd(II) contactsof 3.576, 3.529, and 3.430 Å, whereas complex 4 displaysintra- and intermolecular Pd(II)···Pd(II) contactsof 3.640 and 3.667/4.404 Å, respectively. Complex 6 also exhibits respective intra- and intermolecular Pt(II)···Pt(II)contacts of 3.510 and 4.160 Å. Moreover, complexes 2 and 3b have Na⁺ encapsulated inside theazacrown cavities, and two ClO₄^– anionswith trans- or cis-coordinationto the Na⁺ ions. Besides, complexes 4 and 5b also have two encapsulated Na⁺ or K⁺ ions, respectively, leading to a syn- or anti-form structure through bridging ClO₄^– anions. Unlike complexes 2, 3b, 4, and 5b with encapsulated Na⁺ or K⁺ anions, complex 6 has two encapsulatedAg⁺ and bridging NO₃^– ionsto form a syn-form structure. Remarkably, grindingcomplex 2 with CH₃OH generally led to a similarframework of {[Pt₂(bpy)₂(NaL2)₂(ClO₄)₂](ClO₄)₂}_n as a 1D coordination polymer, and complex 3b can actually be rearranged into complex 3a while grindingwith CH₃OH. Furthermore, complexes 5b and 6 show the respective low-energy emissions at 593 and 555nm at room temperature.

In six-coordinate complexes with S ≥1,deviations from perfect O_h geometry lead to magnetic anisotropy. We have studied (NBuⁿ₄)₂[Re^IVX₆] (Re–X; X = Cl, Br, I; S = 3/2), including zero-fieldsplitting (ZFS) in Re–I, by advanced spectroscopies[far-IR magneto-spectroscopy (FIRMS), high-frequency and -field EPR(HFEPR), and inelastic neutron scattering (INS)]. AC susceptibilityof Re–I shows field-induced SMM (single-moleculemagnet) properties. Unlike Re–I with one unique[ReI₆]^2– center, there are four and threedifferent [ReX₆]^2– centers in the crystallographicunit cells of Re–Cl and Re–Br, respectively. Ab initio calculations determineZFS parameters and show that magnetic anisotropies are influencedby deviations from the O_h geometry and by increased covalency from Re–Cl to Re–Br to Re–I. AlthoughRe–X bond lengths increase from Re–Cl to Re–Br to Re–I, the calculationsreveal that the longer Re–I bonds are compensated by the diffuse,better-overlapping orbitals of I^– ligands. The diffusenessin ligand orbitals likely contributes to the SMM performance of Re–I. The calculations also indicate that deviationsfrom the O_h geometryin [ReX₆]^2– ions are the sole sourceof magnetic anisotropy and that there is no heavy-atom effect fromthe halide ligands. Spin-phonon couplings in Re–I have been probed by FIRMS using results from DFT phonon calculations.

Two new polyoxotungstate (POT)-templated metal-organiccomplexes(MOCs) with various architectures, namely, {[Co₄(3-dpap)₄][W₁₀O₃₂](OH)₄}·12H₂O (1) and {[Co₂(3-Hdpap)₂(H₂O)₄][TeW₆O₂₄]}·3H₂O (2), were synthesized with an N³,N⁵-bis(pyridin-3-ylmethyl)-4H-pyrazole-3,5-dicarboxamide(3-dpap) ligand via solvothermal methods. Complex 1 isa two-dimensional (2D) layer constructed from 2D [Co₄(3-dpap)₄]⁸⁺ architectures and free [W₁₀O₃₂]^4– anions. Conversely, a 1D supramolecularchain is generated for complex 2 via the hydrogen bondinteraction, where the butterfly-like metal-organic units exist inthis architecture. The templating effect from POTs played a crucialrole in leading to the different architectures and spatial distributionof metal-organic units, as well as their electrocatalysis activity.The electrocatalytic properties of the carbon cloth electrodes decoratedwith the title complexes (1–2/CC) were studied,and the hydrogen evolution reaction (HER) was systematically evaluatedin both alkaline and simulated seawater media. Notably, 1/CC demonstrated superior activity, requiring an overpotential ofonly 41.67 mV to achieve a current density of 10 mA cm^–2 for HER in alkaline solution. Furthermore, at the current densityof 100 mA cm^–2, 1/CC also showed enhancedactivity for the oxygen evolution reaction overpotential (η)of 0.5498 V. Density Functional Theory (DFT) calculations indicatedthat the POT species and the 2D [Co₄(3-dpap)₄]⁸⁺ architectures have a pronounced impact on the electrocatalyticperformance.

Metal–organic frameworks (MOFs) have promisingapplicationsowing to their exceptional tunability and ultrahigh porosity. However,the intrinsic microporosity and powdery form cause large mass transferresistance, pipeline clogging, and poor recyclability, which greatlyrestrict their engineering applications. In this work, a hierarchicalporous UiO-66-NH₂-anchored phosphotungstic acid catalyticmembrane (denoted as m-HPW/HP-UNX, where X represents the volume ofadded water) was successfully fabricated via a cast-coating methodusing a casting solution blended with HPW/HP-UNX and poly(vinylidenefluoride) (PVDF) solutions. Among them, hierarchical porous HP-UNXwas synthesized through template-free competitive nucleation in H₂O/acetic acid systems. This solvent-regulated strategy yieldsHP-UNX nanoparticles smaller than 20 nm, which possess a tunable mesoporousstructure and –NH₂ sites, making them ideal supportsfor anchoring bulky phosphotungstic acid (HPW). The resultant m-HPW/HP-UNXcatalytic membrane retains the mesoporous structure of HP-UNX andresolves the separation difficulty of the powdery MOFs. Notably, m-HPW/HP-UN9achieves a desulfurization efficiency of 92%, far exceeding the microporoussamples UiO-66-NH₂ and m-HPW/UiO-66-NH₂. Moreover,the oxidative desulfurization efficiency of the membrane remains approximately90% after cycles, demonstrating a favorable cycling stability. Thestrategy of introducing hierarchical pore structures into moldingmaterials provides a feasible pathway for industrial applicationsof desulfurization catalysts.

Metaldoping provides an effective means of regulating the structure,defect chemistry, and functional properties of ZnO. Here, we reporta tartrate-assisted hydrothermal-calcination strategy for preparingmetal-doped ZnO with tunable compositions. Zn and dopant metal saltsare reacted in the presence of tartrate under hydrothermal conditionsto generate tartrate-derived precursors, which are subsequently convertedinto doped ZnO by calcination in air. Using Mn, Fe, Co, Ni, and Cuas representative dopants, the method was demonstrated for five single-element-dopedZnO samples and representative binary, ternary, quaternary, and quinarycompositions. X-ray diffraction confirmed the formation of hexagonalwurtzite ZnO without detectable secondary crystalline phases, whileenergy-dispersive X-ray spectroscopy and elemental mapping verifiedthe incorporation and distribution of dopant elements. Oxygen evolutionreaction measurements were used to evaluate dopant-dependent catalyticbehavior. Among the tested samples, Fe-ZnO exhibited the highest activity,requiring an overpotential of 297 mV at 10 mA cm^–2 with a Tafel slope of 36.81 mV dec^–1. Structuraland spectroscopic analyses indicate that Fe incorporation induceslattice distortion, oxygen-related defects, and improved interfacialcharge transfer. This work provides a flexible, precursor-based approachfor constructing compositionally tunable doped ZnO materials.

A phenanthroline-bearing sulfonamide ligand (L) andits half-sandwich rhodium(III) and iridium(III) complexes, [(η⁵-Cp*)RhCl(L)]PF₆ (1) and [(η⁵-Cp*)IrCl(L)]PF₆ (2), were synthesizedto determine how metal coordination and metal identity influence structure,solution properties, and anticancer responses. Single-crystal X-raydiffraction established closely related piano-stool geometries withbidentate N,N-coordination of L, while spectroscopicanalyses confirmed the complexes in solution. All compounds were spectroscopicallystable for 72 h under the tested conditions. Coordination shiftedthe lipophilicity of L (log P = 0.78)to hydrophilic values for 1 and 2 (−0.65and −0.91, respectively). The complexes weakly inhibited carbonicanhydrase II and displayed low-affinity binding to human serum albumin;the CT-DNA UV–vis experiment was inconclusive because of substantialspectral overlap and was not used to assign a DNA-binding mode. L showed submicromolar-to-low-micromolar cytotoxicity acrossfour cancer cell lines and pronounced time-dependent mitochondrialdepolarization in NALM-6 cells. Complex 2 retained micromolarpotency but showed weak overall cancer/nonmalignant discrimination,whereas 1 showed a marked preference for NALM-6 cells(IC₅₀ = 4.41 μM; HEK-293 IC₅₀ > 100μM).In NALM-6 cells, 1 produced a pronounced ROS increaseat 6 h that preceded prominent γH2AX signaling, caspase-3/7activation, and apoptosis at 24–48 h, while mitochondrial depolarizationremained comparatively limited. This temporal ordering is consistentwith a redox-associated cellular response but does not by itself establishROS causality or exclude mitochondrial involvement. These matchedanalogs demonstrate that Rh(III) versus Ir(III) coordination can reprogramphysicochemical and cellular response profiles within the same ligandscaffold and identify 1 as a candidate for further mechanism-guidedoptimization.

InNi(II) complexes, spin-state switching is governed by changesin the coordination number and the nature of the ligand field. Wereport the ultrafast photorelaxation of an axial-pyridine-coordinatedoctahedral Ni(II) complex with a phenazine fluorophore using multi-configurationalelectronic structure calculations and quantum wavepacket dynamics.Potential energy surfaces for 20 states of high-spin and low-spinmetal-centered (MC), ligand-centered, and charge-transfer (CT) characterswere computed using the CAS(12,9)/NEVPT2 method and incorporated intoa spin-vibronic Hamiltonian that was propagated using the multiconfigurationaltime-dependent Hartree method. Axial ligation stabilizes a dense manifoldof ³MC states and enhances intersystem crossing via strongspin-orbit coupling. Two Ni-ligand stretching modes drive ultrafastpopulation transfer from bright intraligand CT states into a predissociativeMC state. This promotes fluorescence quenching and predissociativeaxial pyridine bond weakening that can potentially facilitate a coordination-inducedspin-state switch from an octahedral to a square-planar geometry.

The n = 1 Ruddlesden–Popper perovskite LaSrCoO_3.5-δH_x has been exploredas an oxygen ionconductor and catalyst due to its ability to contain both oxygen vacanciesand anionic hydrogen. Here, we compare the phase selectivity and formationof LnSrCoO_3.5-δH_x from LnSrCoO₄ (Ln = La, Pr, Nd, Sm, Eu, and Gd) usingtwo distinct topochemical methods, CaH₂ hydride reductionand the recently reported amalgam-based hydrogen-free reduction─A_xAlGa, with A = Li, Na, and K─witha focus on the A = Na case in particular. These methods are coinedas amalgam-based for their inspiration and similarities to sodium–mercuryamalgams. At T = 300 °C, both techniques yield LnSrCoO_3.5-δ, and at T = 350 °C, hydrogen-free reduction continues to yieldLnSrCoO_3.5-δ, whereas hydride reduction resultsin mixed-phase LnSrCoO_3.5-δ and LnSrCoO_3.5-δH_x. Temperature-dependentmagnetization measurements show that the hydrogen-free reductionshave less parasitic ferromagnetic contributions than those preparedby the CaH₂ method. Powder X-ray diffraction demonstratesthat the amalgam-based method produces pure phase LnSrCoO_3.5-δ over a greater than 50 °C temperature range, whereas the CaH₂ technique results in mixed phase products within that range.In addition to extending the range of known LnSrCoO_3.5-δ and LnSrCoO_3.5-δH_x materials to the smaller rare-earth ions Ln = Sm, Eu, andGd, our results demonstrate the solid-state chemical control thatis possible with emerging topotactic methods.