Further insights into the chemistry of niobium and tantalum pentahalides with 1,2-dialkoxyalkanes: Synthesis of bromo- and iodoalkoxides, spectroscopic and computational studies

High-yield synthesis of heavy rare earth(III) anhydrous solvates: known, new, and unexpected products

Ten anhydrous rare-earth (RE) chloride solvates were prepared by dehydration of RECl3·6H2O with triethylorthoformate (teof) in O-donor solvents as an accessible and general synthetic route. Reactions are quick, safe, mild, easily reproducible, and cost-effective. They run at room temperature or under reflux to give high-yield, pure crystalline products that are either new, such as [Gd2Cl4(μ-Cl)2(PriOH)6] (1) and [{GdCl(μ-Cl)2(thf)2}∞] (2), or obtained for the first time from teof, such as [GdCl3(thf)4] (3), trans-[MCl2(thf)5]trans-[MCl4(thf)2], M = Gd (4), Dy (6), and Y (7), [YbCl3(thf)3] (8), and [MCl3(dme)2], M = Gd (5), Dy (9), and Er (10). Structural and spectroscopic characterization is presented for all products, and variable-temperature magnetic susceptibility data are discussed for the Dy3+ complexes 6 and 9. The latter behaves as a field-induced single-ion magnet for which theoretical (ab initio) and experimental data allowed a non-trivial assignment of overlapping high- (Orbach, Ueff 139 cm-1) and low-temperature (Raman, weff 46.8(2) cm-1) magnetic relaxation mechanisms (1 kOe field). Besides the main products, unanticipated Lewis and redox reactivity led to serendipitous 11, [({Gd3Cl4(μ-Cl)4(μ-H3CCOO)(C3H8O2)(PriOH)4}·PriOH)∞], and 12, [{(thf)2Cl2Gd(μ-Cl)2(μ3-O2)Gd(thf)3}2]·3thf, whose formation is discussed. The final RE3+ anhydrous complexes serve as valuable starting materials for numerous substitution reactions in coordination and organometallic chemistry.

Exploring the physical properties of the new MoX6 (X = Cl or Br) materials

In this study, we present a comprehensive investigation of the mechanical, electronic, optical, and thermodynamic properties of MoX6 (X = Cl or Br) using first-principles calculations within the Wien2k framework, which is based on the full-potential linearized augmented plane wave (FPLAPW) method. Our approach incorporates the GGA+SOC+U formalism, crucial for accurately capturing intricate electronic interactions and spin-orbit coupling (SOC) effects, alongside Hubbard U corrections. This rigorous methodology allowed us to thoroughly explore the mechanical robustness, electronic structure, and optical responses of the MoX6 compounds and their thermodynamic behavior under varying conditions. The results reveal the mechanical stability of the MoX6 compounds with significant insights into their electronic structure, characterized by unique band features that underline their potential utility in advanced optoelectronic devices. The optical analysis highlights key absorption properties, which could be harnessed in photonic applications. Furthermore, the thermodynamic properties suggest a strong stability profile, reinforcing their suitability for diverse materials science applications. To our knowledge, this study represents the first detailed examination of MoX6 compounds using this advanced computational framework. These findings provide a foundation for further theoretical and experimental investigations while offering promising avenues for exploring related compounds with analogous structural and electronic characteristics. This work contributes significantly to the broader understanding of transition metal halides and their potential technological applications.