European Journal of Inorganic Chemistry最新文献

The polypyrazole-containing ligands, N,N,N′,N′-tetrakis((5-tert-Butyl-1H-pyrazol-3-yl)methyl)-1,2-ethanediamine (L1) and N,N,N′,N′-tetrakis((5-Phenyl-1H-pyrazol-3-yl)methyl)-1,2-ethanediamine (L2) were synthesized and shown to form hexadentate monometallic coordination compounds with Co^II, Ni^II, Cu^II and Zn^II metal ions. Exchange studies with the metal ions show binding preference in the order of Ni^II>Co^II/Cu^II>Zn^II. The compounds were confirmed by NMR, UV-Vis studies and the X-ray crystals structures of [Co(L1)](PF₆)₂, [Ni(L1)](PF₆)₂, [Cu(L1)]ClPF₆, [Zn(L1)](PF₆)₂, and [Ni(L2)]Cl_2. In the solid state, the arrangement of the bulky pyrazole units leads to the formation of two distinct cationic pockets containing the N−H groups of the pyrazoles. These cationic pockets are found to bind Cl⁻ or PF₆⁻ counterions through hydrogen bonding and anions titrations revealed good affinity for Cl⁻ and Br⁻. The compounds can be dehydronated up to two times using mild organic bases, highlighting the potential of these ligands to tune the electronic properties of the metal center.

The novel isotypic hexagonal alkaline earth metal nitride chalcogenides Ca₆N₂Se₃, Sr₆N₂Se₃ and Sr₆N₂Te₃ (R$$ (No.167); Z=6) were synthesized from Ca(Sr)/Na flux at 1173 K. The compounds belong to the rare class of ternary metal nitride chalcogenides. The structures feature the shortest Ca/Sr−N bonds within the regular trigonal antiprismatic coordination (Ca−N: 235.17(8); Sr−N: 251.20(6) pm). Two crystallographic distinct nitrogen atoms are coordinated in a trigonal antiprism and a twisted trigonal prism, respectively, and are alternatively condensed via trigonal trans-faces to form one-dimensional chains $$. The chalcogenide ions in comparison realize rather ambiguous environments. Raman spectroscopic data are reported.

Herein, the influence of fluorine substituents on the structural and physical properties of MOFs with aromatic carboxylate ligands is investigated. To achieve this, the focus is limited to a few widely used ligand classes, e. g. terephthalates or trimesates. It is shown that the torsion angle between the phenyl ring and the carboxylate groups plays a decisive role. This can also be transferred to more complex ligands. These considerations clearly show why there are isostructural variants of some MOFs with perfluorinated ligands known (e. g. MIL-53), while for others no successful synthesis has been reported up to now (e. g. HKUST-1). In order to investigate the influence of the fluorination of the linker on the properties of the corresponding MOFs, isostructural systems were analysed more specifically. It was found that the thermal and chemical stability decreases with fluorination, while the absorption of CO₂ in particular is enhanced. With regard to the specific surface area (S_BET), the results are contradictory.

It took 78 years from Mendeleev's proposal of an existence of “eka-manganese” (1869) until it was finally named as technetium (Tc) in 1947. Another 78 years have passed since then. This provides a good occasion to pinpoint what we know and what we still do not know of this radioelement. Technetium is placed near the center of the Periodic Table, in the center of the groups 6, 7, and 8. Some chemical properties of the elements surrounding technetium show trends within the columns or along the rows of the Periodic Table, but a consistent interpretation of these trends is lacking as long as the knowledge on technetium remains incomplete. This is especially remarkable as, on the other hand, the isotope ^99mTc is applied on a daily basis in nuclear medicine. The aim of this paper is to review the fundamental understanding of technetium chemistry, mostly focusing on the research of the last decade, its implications, and its future perspectives. These developments show a picture of growing connections between physicochemical data, fundamental inorganic chemistry, organometallic and coordination chemistry, computational chemistry, and geochemistry.

As an element, cobalt has a very interesting coordination chemistry and great potential to participate in the formation of a variety of complex compounds, that play a significant role in the synthesis of catalytic systems. In the present work, a new cobalt(II) complex compound with an unusual and rare structure, not previously described in the literature, was synthesized. This complex has two 2,2′-bipyridyl ligands, a water molecule and, most interestingly, a sulfate(VI) anion in the Co(II) coordination sphere. Its use and catalytic properties were studied in the oligomerization of selected olefins, where it acted as a precatalyst. The achieved catalytic activity values were rather high (<100 g mmol⁻¹ h⁻¹ ⋅ bar⁻¹), except for the oligomerization process of 2,3-dibromo-2-propen-1-ol using MAO. The obtained oligomers were subjected to structural (FT-IR, SEM, MALDI-TOF-MS) and thermal (TG, DSC) analysis, and the results allowed to characterize their physicochemical properties. The conducted process allowed to determine the effect of the applied activator on the catalytic activity, as well as the structural and thermal properties of the obtained oligomers. In addition, the specific surface area and sorption properties of the oligomerization products were studied, and one of them showed very high CO₂ sorption values (<1.6 mmol g⁻¹).

Unlike most d-block metal complexes, group-12 metal complexes exhibit a lack of visible light absorption involving atomic orbital of metal center, despite the growing demand for visible light-driven photofunctional materials. To overcome this limitation, we previously developed a dinuclear Zn(II) complex that absorbs visible light through an empty σ orbital formed between two proximal Zn atoms and exhibits dual emission at 77 K. However, the roles of the central metal atom in influencing the structural and photophysical properties were not fully investigated. In this study, we synthesized a dinuclear Cd(II) complex, structurally analogous to the Zn(II) complex, to investigate the effects of the central metal atoms on these properties. Structural analyses revealed that both complexes are highly similar, with slightly elongated Cd–Cd distances because of Cd's larger van der Waals radius. Theoretical calculations indicated attractive intermetallic interactions between the central metal atoms in both complexes. Although both complexes displayed negligibly different visible light absorptions, the Cd(II) complex displayed a much higher intersystem crossing rate than the Zn(II) complex, generating distinctly different overall emission profiles. These findings emphasize the crucial roles of the central metal atoms in influencing the structural and photophysical behaviors of dinuclear complexes, providing deeper insights for designing group-12-element-based materials.

The Cu-SAPO-34 catalyst, a promising selective catalytic reduction (SCR) catalyst for the denitration of mobile sources, has attracted widespread research interest due to its wide temperature window, remarkable catalytic performance and good stability. In this study, a series of Cu-SAPO-34 catalysts with varying Cu contents were synthesized by the one-step hydrothermal method. The physicochemical properties of the catalysts were investigated by characterizations, and the reasons for the well-activity catalysts were analyzed. The acidic sites on the SAPO-34 zeolite can adsorb and activate NH₃, while the copper active sites can promote the activation and reduction of NO_x, accelerating the reaction process of SCR. In this study, Cu-SAPO-34 with Cu content of n(Cu)/n(C₉H₂₁AlO₃)=0.075 has good framework stability, which produced more free Cu²⁺ ions and the Cu species are evenly distributed on the carrier surface, and the appropriate amount of acid sites. Therefore, the Cu_0.075-SAPO-34 catalyst exhibits the highest NO conversion performance, maintaining a NO conversion rate above 90 % within the temperature range of 165–450 °C.

In this manuscript we report the synthesis of three methanol solvatomorphs of Fe(II) complexes with the 2-(2-phenyl)-5-[N,N-bis(2-pyridylmethyl)aminomethyl]-1,3,4-oxadiazole (L^Ph−ODA) ligand and three different NCE co-ligands where E=S, Se and BH₃ (C1–C3). The complexes obtained were characterized by single crystal X-ray crystallography and SQUID magnetometry between 2 and 300 K. Complexes C1 and C2 remain in the high spin state over the entire measured temperature window, whereas complex C3 exhibits a solvent dependent spin transition with a T_1/2 of 166 K. Upon heating the sample to 400 K and removing methanol, the complex exhibited a two-step spin transition with the first step having a T_1/2 of 215 K and a second step having a T_1/2 of 137 K.

The reactions of iodoanilines IC₆H₄NRR′-2 with [Pd(PPh₃)₄] gave complexes [Pd(C₆H₄NRR′-2}I(PPh₃)₂] [R=H, R’=H (1 a), Me (1 b); R=R’=Me (1 c)] while a mixture of 1 a, and the dimeric [Pd{μ-C,N-C₆H₄NH₂-2)I(PPh₃)]₂ (2 a) was obtained when the appropriate iodoaniline was reacted with [Pd(dba)₂] (dba=dibenzylideneacetone) and 1 equiv. of PPh₃. The phosphonium salts [Ph₃PC₆H₄NRMe-2]OTf [R=H (3 b), Me (3 c)] formed upon reacting complexes 1 b,c with TlOTf (OTf=CF₃SO₃). Complexes of the type [Pd(C₆H₄NRR′-2}I(N N)] (4) were obtained from the reaction of [Pd(dba)₂] with the appropriate iodoaniline and a N N bidentate ligand (N N=4,4′-di-tert-butyl-2,2′-bipyridine or N,N,N′,N′-tetramethylethylenediamine). Complexes 4 reacted with TlOTf and PPh₃ or XyNC (Xy=C₄H₄Me₂-2,6) to give [Pd(C₆H₄NRR′-2)(N N)(PPh₃)]OTf (5) or [Pd{C,N-C(=NHXy)C₆H₄NRR′-2)(N N)]OTf (6), respectively. In the absence of any added ligand, the reactions of complexes 4 with TlOTf produced the dimeric complexes [Pd{μ-C,N-C₆H₄NHR-2)(N N)]₂(OTf)₂ (7) or the four-membered palladacycles [Pd(κ²-C₆H₄NMe₂-2)(N N)]OTf (8), depending on the substitution degree of the aniline reagent.

The Front Cover illustrates a claw machine extracting a three-dimensional object, shaped to match its claw, from water. This visual symbolizes a Li₂([18]crown-6)₃[Ni(dmit)₂]₂(H₂O)₄ crystal, whose channel structure, formed by aligned [18]crown-6 molecules (orange rings), enables selective ion exchange. The crystal selectively incorporates MeNH₃⁺ from a mixture of organic cations (MeNH₃⁺, EtNH₃⁺, nPrNH₃⁺) in aqueous solution, maintaining its crystalline integrity. More information can be found in the Research Article by S. Nishihara and co-workers.