Том 50, № 3 (2024)

The reaction of tris((2-dimethylaminomethyl)phenyl)methanol ((2-Me₂NCH₂C₆H₄)₃COH) with potassium hydride in THF at –35°C affords dimeric alkoxide {[(2-Me₂NCH₂C₆H₄)₃CO]K(THF)}₂ (I) in a yield of 90%. The reaction of compound I with YbI₂(THF)₂ (1 : 1, 25°C) gives the Yb(II) alkoxyiodide complex {[(2-Me₂NCH₂C₆H₄)₃CO]Yb(μ-I)(THF)₂}₂ (II) in a yield of 57%. Complex II in the crystalline state is dimeric due to two bridging iodide ligands. Unlike the Yb(II) compound, the exchange reaction of complex I with SmI2(THF)2 (1 : 1, 25°C) in THF followed by the addition of dimethoxyethane (DME) involves the oxidation of the metal to form the trivalent samarium complex [(2-Me₂NCH₂C₆H₄)₃CO]₂SmI (III), which is isolated in a yield of 60%. The molecular structures of the complexes are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2259700 (I), 2259701 (II), and 2259702 (III)).

The coordination and extraction properties of two related tripodal ligands differed by types of addition of the triazole fragment and linker length in the {2-[(4-Ph-1,2,3-triazol-1-yl)CH₂CH₂O]C₆H₄}₃P(O) (L¹) and {2-[(1-Ph-1,2,3-triazol-4-yl)CH₂O]C₆H₄}₃P(O) (L²) are compared. The structures of the complexes [Lа(NO₃)3L¹] (I) and [Lu(NO₃)3L¹] (II) are studied in the solid phase (elemental analysis, IR and Raman spectroscopy) and in solutions (IR and multinuclear ¹H, ¹³C, and ³¹P NMR spectroscopy). A normal coordinate analysis at the TPSS-D4/Def2-SVP level is performed for an isolated molecule of the model complex [La{P(O),N³,N²-L³}(O,O-NO₃)₃] (L³ = {2-[(4-Me-1,2,3-triazol-1-yl)CH₂CH₂O]C₆H₄}₃-P(O)). According to the set of spectral and quantum chemical data, ligand L¹ exhibits the tridentate P(O),N²,N² coordination in lanthanide complexes I and II. These are neutral complexes in the solid state and in CD₃CN solutions, and the dynamic equilibrium of the neutral and ionic complexes is observed in CDCl₃. Unlike ligand L¹, ligand L² exhibits the tetradentate P(O),N³,N³,N³ coordination in the [Ln(NO₃)₃L₂] complexes with the same metals (Ln = La³⁺, Lu³⁺) in solutions. The efficiency of extraction of microquantities of f elements from the aqueous phase to 1,2-dichloroethane by compounds L¹ and L² is discussed in comparison with the structures of the complexes of both ligands in solutions.

Template condensation of S-methylisothiosemicarbazones of acetyl- or benzoylacetone with 8-quinolinecarboxaldehyde in the presence of nickel(II) and copper(II) ions gave four new mononuclear coordination compounds [NiL¹]I (I), [CuL¹I] (II), [NiL²]I (III) и [CuL²I] (IV). The chemical composition of the products was confirmed by elemental analysis, IR spectroscopy, and mass spectrometry, and the crystal structure of compounds I and II was determined by X-ray diffraction analysis (CCDC no. 2266386, 2266387). X-ray diffraction study revealed a square planar coordination environment of the central ion of the cationic Ni(II) complex and square pyramidal geometry for the molecular Cu(II) complex.