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.

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

“…Additionally, analysis of Pr 4 single-crystal data shows that the crystal structure is isomorphous to the recently reported La 4 and Nd 4 analogs (Tsymbarenko et al, 2022) and is composed of isolated tetranuclear complex cations, [Pr 4 (OH) 4 (tfa) 3 (deta) 4 (detadcH) 2 ] 3+ , with a cubane-like Pr 4 (OH) 4 core (Fig. 8 and Fig.…”

“…Polynuclear lanthanide complexes can be synthesized by controlled hydrolysis in the presence of organic bases. We have previously reported on the isolation of crystalline polynuclear hydroxo complexes composed of hexa-and tetranuclear molecular clusters (Grebenyuk et al, 2019;Tsymbarenko et al, 2022). The presence of strongly scattering Ln atoms and the high solubility of their trifluoroacetates (Htfa -trifluoroacetic acid) in common organic solvents allows us to study the process of polynuclear core assembly in solution using the PDF technique.…”

“…The Pr2 atom is coordinated by a bichelating deta ligand (N4-N6), three 3 -OH groups (O1, O2, O1 i ), one chelatobridging detadcH À (O6 and O8) and one bridging tfa -(O5). The detadcH À ligand forms in situ due to CO 2 absorption from air by deta during the slow crystallization of the reaction mixture (Tsymbarenko et al, 2022). The Ln 4 family is the first example of structurally characterized complexes with the detadcHligand and is of high interest from the viewpoint of their application in technologies in carbon dioxide trapping and storage (Septavaux et al, 2020;Poisson et al, 2016;Kadota et al, 2021).…”

Tuning the Cerium-Based Metal–Organic Framework Formation by Template Effect and Precursor Selection

“…Recently, we have elaborated the synthetic routes for tetranuclear {Ln 4 (OH) 2 }, {Ln 4 (OH) 4 } and hexanuclear {Ce 6 O 8 }, {Ln 6 (OH) 8 } lanthanide carboxylate complexes. − The intent of the current study was to examine the possibility of creating new MOFs by linking the di-, tetra-, and hexanuclear Ce complexes into an extended 3D framework via the terephthalate linker.…”