European Journal of Inorganic Chemistry最新文献

Reaction of 4-methylphenylacetylide with the known chlorido platinum(II) complex bearing the cyclometalated 1,3-bis(pyridin-2-yl)-4,6-difluoro-benzene ligand afforded a novel alkynyl platinum(II) complex, 1, that was fully characterized by elemental analysis, NMR and UV-visible spectroscopies, by photoluminescence measurements, and by computational modelling. Its structure was determined by X-ray diffraction studies on a single crystal whereas its second-order nonlinear optical (NLO) properties were determined in solution by the Electric-Field Induced Second Harmonic generation method. The novel multifunctional complex 1 is characterized by good luminescence properties, like the related chlorido Pt(II) complex, but by a much higher second-order NLO response.

A novel series of isostructural lanthanide coordination polymers with the general formula [Ln₂(PDA)₃(DMF)₂] (where Ln³⁺= La, Nd, Pr, Tb, Sm and Eu, DMF= N,N’-dimethylformamide and PDA =1,3-phenylenediacetate) were hydrothermally synthesized and further characterized by vibrational spectroscopy, thermal analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, and powder and single-crystal X-ray diffraction techniques. In addition, from the crystallographic data, it was possible to determine the topology of the structure, finding that the network consists of 5-connected nodes with topological type: nov; 5/4/o8 and point symbol (4⁴.6⁶). To study the luminescence properties regarding potential energy transfers among the building blocks, lanthanum-based samples doped with Tb (III) and Eu (III) (1 %, 2 %, 5 % and 10 %) were analyzed in solid state. Upon ligand sensitization, 4 f transitions could be observed confirming an “antenna effect” of the PDA ligand. These new compounds are potential materials for the construction of photoluminiscent devices.

Cation-π interactions involve different metallic cations, where the bonding characteristics depend on the involved species. Here, we unravel the interaction nature features for Ga(I)-π interactions, where different contributing terms ensure an efficient coordination of one and two Ga(I)-atoms towards a common aromatic ring. Our results show a more balanced contribution of about ~70 % from electrostatic character and of ~30 % from orbital interaction for the prototypical GaCp, GaCp*, [Ga₂Cp]⁺ and [Ga₂Cp*]⁺ species. Such description strongly contrasts with the highly electrostatic character in alkali and alkaline-earth metals counterparts. The variation from mono to inverted sandwich complexes leads to a decrease in the interaction energy from −180.9 to −148.1 kcal/mol for Cp based species, and from −184.4 to −155.5 kcal/mol in Cp* counterparts, owing to a decrease in both electrostatic and orbital stabilizing contributions. Thus, the aromatic rings exhibit coordination versatility towards one or two Ga(I) cations, retaining a sizable stabilization of the Ga(I)-π interaction. Thus, cation-π interactions are able to exhibit different types according to the involved metal cation, which relies on a more electrostatic/orbital balanced interaction, which serves to evaluate further mono and inverted sandwich complexes sharing a common aromatic ring.

Metal-organic frameworks of the CPO-27 (MOF-74) series are known for their high adsorption capacities for nitrogen oxides. On the other hand, significantly varying and partly contradictory results were reported regarding their stability to moisture. This aspect has hampered the use of these MOFs in air filtration applications. Here, we show that the stability of CPO-27 materials towards moisture and CO₂ crucially depends on the synthesis parameters. By precisely adjusting the synthetic parameter-property relationship, it is possible to prepare a highly stable CPO-27(Ni) MOF by a simple precipitation in water. To demonstrate the capacity for NO₂, breakthrough experiments were performed under dry and wet conditions (55% relative humidity). Extremely high values of nearly 0.74 g/g in dry conditions and 1.23 g/g under wet conditions were achieved. These results pave the way for the toxicologically safe and cost-effective preparation of a moisture-stable CPO-27(Ni), bridging the gap to a potential industrial application of the material for the selective adsorption of toxic gases, such as NO₂.

The Front Cover shows the electrocatalytic activity of a cobalt corrole for CO₂ reduction. In their Research Article, A. Aukauloo, G. Canard and co-workers report how they designed an electron-deficient A₂B-type corrole featuring two −CF₃ groups and a cyanobenzene at the meso positions, along with its cobalt complex. When adsorbed on a carbon electrode, the A₂B cobalt corrole exhibited excellent catalytic performance for CO production and demonstrated the ability to convert CO₂ to methanol.

Birefringent materials play indispensable roles in modulating the polarization of light and are vital in laser science and technology. Units with π-conjugation are regarded as potential functional modules for large optical anisotropy, such as planar [BO₃]³⁻, [B₃O₆]³⁻, and [B₃O₃(OH)₃]. However, the discovery of deep-ultraviolet (DUV, λ ≤200 nm) birefringent materials still faces a serious challenge due to the limited band gap. Replacing hydroxyl anions [OH]⁻ with fluorine anions F⁻ in borates can cause the blueshift of the ultraviolet (UV) cutoff edge, however, the effect of this replacement on π-conjugation units has not been systematically studied. Herein, based on template materials metaboric acid α-B₃O₃(OH)₃ with planar [B₃O₃(OH)₃] units, we proposed an OH/F substitution strategy designing potential DUV birefringent materials. The designed B₃O₃(OH)₂F, B₃O₃(OH)F₂, and B₃O₃F₃ exhibit large birefringence from 0.123 to 0.146 at 546 nm with DUV transparency based on first-principles calculations, exceeding the performance of traditional α-BaB₂O₄. Further electronic structure analysis reveals the band edge and bonding difference between [OH]⁻ and F⁻, indicating the corresponding designed novel [BO₂F], [B₃O₃(OH)₂F], [B₃O₃(OH)F₂] and [B₃O₃F₃] units can act as potential DUV birefringent-active functional modules with large structure anisotropy. This work offers the chemical difference of F⁻ and [OH]⁻ anions, and design-strategy of new DUV birefringent materials.

The intercalation chemistry is essential in the application of anion-exchangeable layered metal hydroxides. However, much of the key information regarding intercalated anions, such as the degree of ordering and arrangement is still not clear or missing to date, due to the difficulty in probing the local environment of anions by routine characterization techniques. Herein, we employed solid-state NMR (ssNMR) spectroscopy to offer valuable complementary insights into the ordering and arrangement of a series of monocarboxylate anions (RCOO⁻: R=HO, H, CH₃, C₂H₅, and C₃H₇) within the interlayer space of two layered yttrium hydroxides (LYH-Cl and LYH-Br). The results imply that the two smaller carboxylate anions (R=HO and H) are disordered after intercalation, while the larger carboxylate anions (R=CH₃, C₂H₅, and C₃H₇) are relatively ordered. We further explored if the intercalated anions are parallel arranged as those in sodium salts or antiparallel arranged as those predicted in the majority of previous reports. We uncovered that the intercalated anions are antiparallel arranged based on the formation energy obtained in density functional theory calculations and ssNMR data. Our results therefore contribute to a deeper and comprehensive understanding of the intercalation chemistry of layered rare earth hydroxides.

A surrounding matrix is known to alter nanoparticle spin transitions, the solid state structural phase changes associated with transitions between high spin (HS) and low spin(LS) states. To better quantify how the spin transition solid and surrounding matrix interact, several series of core-shell particles were prepared based on Rb_xCo[Fe(CN)₆]_z ⋅ nH₂O, RbCoFe-PBA, as spin transition core with isostructural shells of different compositions and thicknesses. Synchrotron PXRD through the thermal high HS to LS, the LS to photoexcited high spin (PXHS), and thermal PXHS to LS transitions, show the activation energy is lowered as shells become thicker and stiffer. Calorimetry data coupled with transition state theory analysis indicate the core stiffens in the core-shell particles relative to the uncoated particles. The conclusion is supported by microstrain analysis that shows stiffer shells limit the extent to which the core distorts as individual sites transition, leading to the lower activation energy. Finally, differences in lattice mismatch with different shell materials are shown to alter the mechanism by which the transition progresses.

Here, we report the preparation, structures and reactivity of iron(II) PNP pincer complexes bearing one, two or three η¹-acetylide ligands bound to the metal center. The described complexes are accessible through the reaction of either one, two or ≥3 equivalent of LiCCR (R=SiMe₃, Ph) with the dibromide complex [Fe(PNP)Br₂] (1). Through increasing the number of η¹-acetylides the overall ligand field strength can be modulated resulting in S=2, S=1 and S=0 spin states for mono-, bis- and tris-acetylated complexes, respectively. These findings are supported by DFT calculations on the spin state spitting in these complexes and appear to affect their binding affinity towards additional co-ligands. The Fe(II) mono-, bis- and tris-acetylides were tested as catalyst in the catalytic dimerization of terminal alkynes. These test reactions revealed that only the bis-acetylated complexes are catalytically competent while mono-acetylated species are inactive. The tris-acetylated complexes were found to be off-cycle intermediates in the presence of lithium acetylides.

M₉- and M₁₂-metal clusters appear as face-sharing double-clusters in (Pb₉Br₁₉)₂(Pb_1.5Br₂)₂(melem)₃ (6) and as triple-clusters in (Pb₁₂Br₂₅)₄(Pb_1.67Br₂)₃(melem)₄ (7). All compounds are characterized by single-crystal and powder X-ray diffraction, and further validated by infrared (IR) spectroscopy and ²⁰⁷Pb and ^79/81Br NMR studies on (5). Photoluminescence studies on compound (6) reveal emission at 430 nm while the emission of (5) is completely quenched.