Novel mononuclear mixed ligand complexes of heavy lanthanide trifluoroacetates with diethylenetriamine

Diverse Coordination Chemistry of the Whole Series Rare-Earth L-Lactates: Synthetic Features, Crystal Structure, and Application in Chemical Solution Deposition of Ln2O3 Thin Films

Rare-earth (RE, Ln) carboxylates are widely studied as precursors of RE oxide-based nanomaterials; however, no systematic studies of RE L-lactates (HLact = 2-hydroxypropanoic acid) have been reported to date. In the present work, a profound structural investigation of RE L-lactates is carried out. A family of RE lactate complexes of the general formula LnLact3∙nH2O (Ln = La, Ce-Nd, Sm-Lu, Y; n = 2-3) are synthesized and characterized by CHN, TGA, and FTIR as well as by powder and single-crystal XRD methods.The existence of four novel structural types (1-Ln-4-Ln) is revealed. Compounds of the 1-Ln type (Ln = La, Ce, Pr) exhibit a chain polymeric structure, whereas 2-Ln-4-Ln compounds are molecular crystals consisting of dimeric (2-Ln; Ln = La, Ce-Nd) or monomeric (3-Ln-Ln = Sm-Lu, Y; 4-Ln-Ln = Sm-Gd, Y) species. The crystal structures of 1-Ln-4-Ln compounds are discussed in terms of their coordination geometry and supramolecular arrangement. Solutions of yttrium and lanthanum lactates with diethylenetriamine are applied for the chemical deposition of Y2O3 and La2O3 thin films.

Multifunctional Electrolyte Additive Enables Highly Reversible Anodes and Enhanced Stable Cathodes for Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) are charming devices for large-scale power grid energy storage because of their characteristics of environment friendliness, low cost, high abundance, and safe operation. However, the inferior reversibility of the anode and the loss of cathode capacity always hinder the application of AZIBs. Herein, we propose a simple multifunctional electrolyte additive, diethylenetriamine (DETA), which can inhibit the formation of zinc dendrites and the occurrence of side reactions on the anode, reconstruct the solvated structure and uniform ion flux in the electrolyte, restrain the dissolution of active materials, and induce the crystal transformation on the cathode concurrently. Molecular dynamics Simulation and density functional theory both verified the extraordinary efficacy of DETA. With the assistance of DETA, the Zn anode gained a life of up to 2000 h, and the cathode with commercial V₂O₅ retained a capacity of 125.2 mA h g^-1 at the 1000th discharge process. From the perspective of practical application, this work can open up the application prospect of AZIBs in large-scale energy storage and provide reference for the subsequent works. The findings will greatly promote the application of AZIBs in large-scale energy storage and provide more inspiration for future research.

Quick and robust PDF data acquisition using a laboratory single-crystal X-ray diffractometer for study of polynuclear lanthanide complexes in solid form and in solution

Self-assembled polynuclear lanthanide hydroxo complexes are important objects in the reticular chemistry approach to the design of various functional materials. Revealing their structure in the solid state and understanding the molecular mechanism of self-assembly in solution require a universal and reliable structural method. Pair distribution function (PDF) analysis is a powerful technique which enables structural insight for a wide range of crystalline and amorphous materials on the nanoscale, but commonly measurements are performed at synchrotron X-ray sources or on specially designed laboratory diffractometers. In the present paper, a standard Bruker D8 QUEST single-crystal X-ray diffractometer equipped with a micro-focus Mo tube and CMOS Photon III detector was adapted to measure PDF data of high quality with Q max = 16.97 Å–1 for solid and liquid samples. An improved data collection strategy and the original data reduction software FormagiX enable calibration and azimuthal full-frame integration of 2D frames, delivering reliable PDFs up to 80 Å with instrumental parameters Q damp = 0.018 Å−1 and Q broad = 0.010 Å−1. The effectiveness of the developed approach was demonstrated with reference samples and real-case studies of tetranuclear lanthanide hydroxocarboxylates in solid form and in solution.

Single-Source Precursors for Chemical Solution Deposition of Up-Converting NaLnF4 Thin Films

Novel single-source precursors based on sodium and lanthanide pentafluoropropionates have been developed for chemical solution deposition of NaLnF4 thin films (Ln = Y, Yb, Er, Tm). A series of [Ln2(pfp)6Qn] (Q = H2O, diglyme) and mixed-metal NaLn(pfp)4Qn were synthesized and characterized by X-ray diffraction (XRD) and thermogravimetric analysis (TG-DTA). Thermal decomposition of individual Na(pfp) and Ln(pfp)3 occurs at different temperatures while single-source NaLn(pfp)4 decomposes with the transformation to NaLnF4 in a single stage at 280 °C. Further crystallization of NaLnF4 was studied by variable-temperature powder XRD, which shows two phase transformations from cubic NaLnF4 to hexagonal NaLnF4 at 310 °C and back to a high-temperature cubic phase at 560 °C. The thin films of NaY0.78Yb0.2Er0.02F4 prepared by the dip-coating technique on Al2O3 substrates showed intense up-converting luminescence in green and blue regions under 980 nm excitation.

Tetranuclear Hydroxo Complexes of Rare-Earth Elements with the Cubane Core as Products of Self-Controlled Hydrolysis

Abstract

Tetranuclear hydroxo complexes [La4(Deta)4(OH)4(Tfa)3(DetadcH)2](HTfa)(H2O)7(Tfa)3 (I) and [Nd4(Deta)4(OH)4(Tfa)3(DetadcH)2](H2O)n(Tfa)3 (II) with diethylene-N,N′-dicarbamate anions (DetadcH–) are synthesized for the first time by the reactions of lanthanum trifluoroacetate and neodymium trifluoroacetate with a solution of diethylenetriamine (Deta) in air under the self-controlled hydrolysis conditions and are characterized by X-ray diffraction, powder X-ray diffraction, IR spectroscopy, and elemental analysis. Compounds I and II contain the same-type complex cationic fragment with the cubane metal–oxygen core stabilized due to four chelate Deta ligands and two bridging DetadcH– ligands. The DFT calculations of the geometry and vibrational spectrum of the [La4(Deta)4(OH)4(Tfa)3(DetadcH)2]3+ complex cation are performed.