Dalton Transactions

doi: 10.1039/d4dt90079kpmid: N/A

doi: 10.1039/d4dt90080dpmid: N/A

doi: 10.1039/d4dt90081bpmid: N/A

Kitagawa, Yuuki; Ueda, Jumpei; Tanabe, Setsuhisa

doi: 10.1039/d4dt00191epmid: 38686957

Trivalent europium (Eu3+) ions show red luminescence with sharp spectral lines owing to the intraconfigurational 4f–4f transitions. Because of their characteristic luminescence properties, various Eu3+-doped inorganic compounds have been developed to meet the demands of optoelectronic devices. Regardless of shielding by the outer 5s and 5p orbitals, the properties of the Eu3+:4f–4f transition depend on the local environment, such as the shapes of the coordination polyhedra, site symmetry, nephelauxetic effects, crystal field effects, and bonding character. Mixed-anion coordination, where multiple types of anions surround a single Eu3+ ion, can directly affect the optical properties of Eu3+. We review the luminescence properties of Eu3+ ions in mixed-anion compounds of the oxynitride YSiO2N and oxyhalides YOX (X = Cl or Br). Oxynitride and oxyhalide coordination results in characteristic transition probabilities and branching ratios of the 5D0 → 7F0–6 transitions due to distorted structural environments and red-shifted charge transfer excitation bands due to an upward shift of the valence band. The expected and experimentally observed features of Eu3+ luminescence in mixed-anion compounds are outlined based on band and Judd–Ofelt theories. Future applications of the intense red luminescence at ∼620 nm under near-ultraviolet light illumination in Eu3+-doped mixed-anion compounds are introduced, and material design guidelines for new functional Eu3+-doped phosphors are presented.

Song, Xueling; Li, Xiaoman; Song, Yuxuan; Bi, Jingyi; Wang, Lei; Wang, Jigao; Liu, Junjie; Li, Yanyan; Wang, Hui

doi: 10.1039/d3dt04144apmid: 38685829

The photocatalytic technique has been widely recognized as a feasible technological route for sustainable energy conversion of solar energy into chemical energy. Photocatalysts play a vital role in the whole catalytic process. In particular, organolead halide perovskites have become emerging photocatalysts, owing to their precisely tunable light absorption range, high carrier diffusion mobility, and longer carrier lifetime and diffusion length. Nevertheless, their intrinsic structural instability and high carrier recombination rate are the major bottlenecks for further development in photocatalytic applications. This Frontier is focused on the recent research about the instability mechanism of organolead halide perovskites. Then, we summarize the recently developed strategies to improve the structural stability and photocatalytic activity of organolead halide materials, with an emphasis on the construction of organolead halide crystalline catalysts with high intrinsic structural stability. Finally, an outlook and challenges of organometal halide photocatalysts are presented, demonstrating the irreplaceable role of this class of emergent materials in the field of photo-energy conversion.

Charles-Blin, Youn; Hatim, Oumaima; Clarac, Mélissa; Perbost, Anne-Marie; Liminana, Solveine; Lopez, Laura; Gimello, Olinda; Guérin, Katia; Dubois, Marc; Deschamps, Michael; Flahaut, Delphine; Martinez, Hervé; Monconduit, Laure; Louvain, Nicolas

doi: 10.1039/d4dt00600cpmid: 38695771

Volkov, Sergey; Yukhno, Valentina; Banaru, Alexander; Deyneko, Dina; Aksenov, Sergey; Charkin, Dmitri; Povolotskiy, Alexey; Savchenko, Yevgeny; Antonov, Andrey; Krzhizhanovskaya, Maria; Ugolkov, Valery; Firsova, Vera; Vaitieva, Yulia; Boldyrev, Kirill; Bubnova, Rimma

Ma, Ying-Zhao; Yu, Lian; Zhou, Qi; Fu, Wensheng

doi: 10.1039/d4dt00724gpmid: 38690725

Treatment of Yb(ii) complex [L2Yb(THF)2] (L = PhC(NSiMe3)2) with elemental sulfur, selenium or tellurium resulted in the isolation of a series of dinuclear Yb(iii) complexes featuring side-on bound S32− (1), Se22− (2) or Te22− (3) moieties, respectively. Magnetic study on these complexes revealed that 3 is a rare lanthanide telluride single-molecule magnet (SMM).

Taniguchi, Ayano; Fujita, Takeshi; Kobiro, Kazuya

doi: 10.1039/d3dt04131jpmid: 38536113

A high-entropy porous spinel oxide [(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4] was synthesized via a solvothermal method and calcination. Solvothermal conditions yielding homogeneous precursor composites with five metals were optimized. Low-temperature calcination of the amorphous composites at 500 °C for 60 min yielded porous spheres formed by small primary particles, with crystal structures attributed to single-phase spinels. The homogeneity of the five elements in the spheres was verified via scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy analysis. The high-entropy (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4 spheres exhibited superior catalytic activity and long-term stability for the reverse water–gas shift reaction at 700 °C for at least 15 h. The importance of the Cr component in stabilizing the spinel structure was demonstrated. Mn, Fe, Co, and Ni served as active sites in the reaction. The advantage of solvothermal synthesis for porous high-entropy materials was discussed.

Prus, A.; Owarzany, R.; Jezierski, D.; Perkowski, K.; Fijalkowski, K. J.

doi: 10.1039/d4dt00682hpmid: 38700116

Thermal decomposition of NH3BH3 and Li(BH3NH2BH2NH2BH3) was investigated at temperatures up to 1000 °C under various conditions with an inert atmosphere. It was found that complete dehydrogenation of ammonia borane towards amorphous boron nitride (a-BN) occurs at 850 °C when using monel reactors or at 1000 °C with the hot isostatic pressing method (HIP), which is significantly lower than was earlier reported. Li(BH3NH2BH2NH2BH3) was found to decompose towards hexagonal boron nitride (h-BN) at 1000 °C with the HIP method but at 850 °C in monel reactors towards a mixture of a-BN and h-BN. The findings are confirmed by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM).