European Journal of Inorganic Chemistry最新文献

The synthesis of the ethylenediamine-derived bisphosphine ligand, (o-PPh₂ (C₆H₄)C(O)NH(CH₂))₂ (1) (hereafter referred to as PN^HN^HP), is described via two methods distinct from previously reported procedures. Treatment of ligand 1 with Pd(COD)Cl₂ afforded the trans-dichloropalladium complex [PdCl₂(PN^HN^HP)-κ²-P,P] (2). In contrast, the reaction of 1 with Pd(COD)Cl₂ in the presence of a base led to the formation of the tetradentate cis-complex [Pd(PNNP)-κ⁴-P,N,N,P] (3). Similarly, ligand 1 reacted with Pt(COD)Cl₂ to yield the corresponding cis-complex [Pt(PNNP)-κ⁴-P,N,N,P] (4). Reaction of 1 with NiCl₂(DME) in the presence of a base resulted in the formation of [Ni(PNNP)-κ⁴-P,N,N,P] (5). Notably, exposure of the cis-palladium complex 3 to HCl gas led to its conversion to the trans-complex 2, while the cis-platinum complex 4 remained unaffected. Density functional theory (DFT) calculations confirm that the conversion of 3 to 2 is thermodynamically favorable, with a Gibbs free energy change (ΔG) of −29.7 kcal mol. Furthermore, treatment of ligand 1 with cuprous halides yield [CuX(PN^HN^HP)-κ²-P,P] (6: X = Cl; 7: X = Br; 8: X = I). Reaction with Cu(NCCH₃)₄BF₄ produced the dinuclear complex [Cu₂(PN^HN^HP)₂-κ⁴-P,O,O,P]BF₄ (9).

Due to the depletion of traditional fossil resources and the increasing environmental problems, the utilization of sustainable biomass resources has become imperative. The selective oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) has attracted much attention in recent years. However, the large-scale production of DFF remains a challenge given the low dosage of HMF in previous research. In this contribution, a desirable DFF yield of 90.5% is obtained from concentrated HMF (130 °C, 2.0 MPa oxygen, 8 h) over the prepared Ru/MnO₂ catalyst with abundant oxygen vacancies (O_V). The Ru/MnO₂ catalyst with high O_V exhibits a weak MnO bond intensity resulting in high lattice oxygen (O_L) reactivity, which promotes a high catalytic activity of HMF oxidation. Reusability studies show that the Ru/MnO₂ catalyst is stable and reusable. Furthermore, the direct production of DFF from fructose is also successfully realized via two consecutive steps, leading to a cost-efficient oxidation of HMF solution and facilitating the industrial production of DFF. This research provides profound insights into the selective oxidation of HMF to DFF, thereby fostering further investigations into the conversion of fructose into high-value chemicals.

The layered Zintl phase Li₂ZnSi is a structural analog of intercalated graphite with hexagonal layers of Zn and Si atoms separated by Li atoms (space group P6₃/mmc, a = 4.2458(2) Å, c = 8.224(1) Å). Single-crystal X-ray diffraction reveals Zn relocation into the center of the Zn₃Si₃ rings in 4% of the hexagonal layers. The Zn relocation is coupled with Li migration. The resulting 2D defects can be modeled either as 60° slab rotations or, alternatively, as layer translations by k = 1/3 [1,−1,0]. Li₂ZnSi shows metal-type electrical resistivity (ρ = 1.18 μΩ m at 300 K) and exhibits significantly enhanced diamagnetism, suggesting orbital contributions akin to those in graphite. This study demonstrates transition-metal mobility in a layered Zintl phase, generating localized 2D defects that leave the local coordination of each atom unchanged. This mechanism is relevant for understanding defect tolerance in structurally related electrode materials.

A series of organotin(IV) complexes featuring the pro-ligand 2,6-diacetylpyridine bis(2-methylbenzoylhydrazone) (H₂L^Me) and various axial ligands have been synthesized. The reactions of H₂L^Me with R₂SnO (where R = Me, n-Bu, n-Oct, or t-Bu) and n-BuSnCl₃ in anhydrous toluene yielded the seven-coordinate complexes [Me₂Sn(L^Me)] (1), [n-Bu₂Sn(L^Me)] (2), [n-Oct₂Sn(L^Me)] (3), [t-Bu₂Sn(L^Me)] (4), and [n-BuSn(L^Me)Cl] (5), respectively. Subsequent treatment of complex 5 with NaN₃ and NH₄SCN afforded the corresponding isothiocyanate and azide derivatives, [n-BuSn(L^Me)N₃] (6), and [n-BuSn(L^Me)NCS] (7), respectively. Single crystal X-ray diffraction studies confirmed that the tin centers in complexes 1, 2, 4, 6, and 7 adopt a seven-coordinate geometry with a pentagonal bipyramidal configuration. The κ-N³O² donor set of the ligand occupies the equatorial plane, while the axial positions are occupied by either two R groups, or one R group and one Cl, N₃, or NCS ligand, depending on the specific complex. In addition to X-ray diffraction analysis, all complexes 1−7 are characterized using Fourier transform infrared spectroscopy, high-resolution mass spectrometry , and solution-state Fourier transform nuclear magnetic resonance spectroscopy. The structural distortion within the SnN₃O₂ equatorial plane, attributed to positional shifts of the Sn(IV) center, are also discussed.

The redox properties of organic molecules like quinones are generally tuned by substitutions at the π-conjugated system or by changing the size of the π-conjugated core. Here, it analyzes the change of the redox properties within a series of isomeric molecules, differing only in the substitution pattern of the groups responsible for the redox activity. The seven redox-active molecules studied in this work, all composed of two guanidino and two thiolato substituents attached to a benzene core, can be reversibly oxidized to the dications, with the radical monocations as intermediate redox states, but the redox potentials and the potential separations between the first and second redox steps vary significantly with the substitution pattern. Distinct hyperfine coupling patterns observed in the EPR spectra of the radical monocations, in alliance with quantum-chemical calculations are used to show that, depending on the substitution pattern, semiquinonato-type or allyl radical–allyl cation-like structures are adopted. Reactions with Cu^II salts give different results depending on the substitution pattern, the copper coligands, and the guanidino group. Paramagnetic dinuclear Cu^II complexes with the neutral molecule as bridging ligand or diamagnetic Cu^I compounds with the redox-active molecules in their oxidized, dicationic redox state are formed.

The oxidation of Au powder with UF₆ in anhydrous hydrogen fluoride (aHF) under a CO atmosphere yields the previously reported nonclassical carbonyl [Au(CO)₂][UF₆], with AuC bond lengths of 1.971(10) and 1.973(10) Å and CO bond lengths of 1.146(15) and 1.088(13) Å. Its composition is now proven by the determination of its crystal structure and powder X-ray diffraction on the bulk phase. A Raman spectrum is successfully recorded and the CO vibration is observed at 2250 cm⁻¹. The nonclassical carbonyl compound [Au(CO)₂][UF₆] is synthesized by reacting Au powder, CO, and UF₆ in aHF. Its crystal structure is determined by single-crystal X-ray diffraction for the first time. Quantum-chemical calculations with the PBE0 hybrid density functional theory method (DFT-PBE0) for the crystal structure of [Au(CO)₂][UF₆] and the [Au(CO)₂]⁺ cation in the gas phase are carried out to allow for a comparison and assignment of the Raman bands.

Selective peptide ligands for lanthanides (Ln) have multiple applications in, for example, Ln-separation and recycling or as lanthanide-binding tags. Optimizing peptides for Ln-binding can be cumbersome and many techniques need high sample volumes. Here short 12-aminoacid peptides are investigated based on the metal-binding loops of the natural Ln-binding protein lanmodulin with advanced gas-phase techniques such as ion mobility spectrometry, collision-induced dissociation, and electrospray ionization to gain insight into binding residues and possible differences between sequences. Both the natural sequences as well as peptides that are synthesized in “reverse” order are investigated and it is found that the trends observed in solution measurements are well reproduced by gas-phase measurements.

The Front Cover demonstrates how a nickel pincer catalyst was used to hydrogenate CO₂ into methanol at moderate temperatures in both aqueous and solid–gas phases. Compared to the aqueous phase, the solid-gas phase demonstrated greater efficiency. By hydrogenating tagged CO₂ in the presence of base, GC-MS verified the production of methanol. More information can be found in the Research Article by B. S. Mallik, E. Nordlander, S. K. Padhi and co-workers (DOI: 10.1002/ejic.202500138).

The Cover Feature presents a vibrant cyclic flowchart illustrating the catalytic research workflow. It begins with X-ray diffraction (XRD) data, followed by Rietveld refinement and extraction of structural parameters. These insights guide catalyst design/modification, which is then tested in catalytic reactions, culminating in catalytic activity results, thus completing the research cycle. More information can be found in the Review by L. G. Possato and co-workers (DOI: 10.1002/ejic.202500051).

The design of micellar catalysts is instrumental in transferring metal-catalyzed organic reactions into aqueous reaction media and enabling catalyst reuse. Herein, it is reported that phosphinoferrocene amidosulfonate Ph₂PfcC(O)NHCH₂SO₃(HNEt₃) (1, fc = ferrocene-1,1′-diyl) and its chlorogold(I) complex [AuCl(1-κP)] (8) form stable micelles in water. The latter compound is found to be an efficient, self-activating catalyst for the gold-catalyzed cyclization of N-propargyl benzamide into 4,5-dihydro-5-methylene-2-phenyloxazole in a water-ethyl acetate mixture. Structure determination of 8·½CH₂Cl₂ reveals extensive hydrogen bonding between the polar amidosulfonate pendants, in line with the compound's surfactant-like behavior. Density functional theory calculations of the plausible LAu⁺ type catalyst suggest a possible in situ self-activation of complex 8 in water via chloride loss, possibly facilitated by the amidosulfonate group and the formation of Au(I)-aqua species.