Syntheses, structures and magnetic properties of symmetrical Schiff-base supported dinuclear Ln(<scp>iii</scp>) compounds
作者:Shuang-Yan Lin、Chunlai Wang、Zhikun Xu
DOI:10.1039/c6ra16669e
日期:——
Three dinuclear Ln(III) compounds, [Ln2(H3L)2(PhCOO)6] (Ln = Sm (1), Dy (2)) and [Dy2(H4L′)2(PhCOO)4]·2CH3CN (3) have been synthesized and structurally and magnetically characterized. Structure analyses revealed distinct structural features in compounds with different symmetrical arms of Schiff-base ligands. With the symmetrical two-arm Schiff-base ligand H3L, dinuclear Ln(III) compounds 1 and 2 were synthesized
A series of tetranuclear lanthanide compounds constructed by in situ polydentate ligands: synthesis, structure, and SMM behaviour of the Dy<sub>4</sub>compound
Four tetranuclear lanthanide compounds with formulas [Ln4(HL)2(H3L)2(H2L′)2(PhCOO)2]·6CH3OH (Ln = Nd (1), Sm (2) and Gd (3)) and [Dy4(DFMP)2(H2L)2(HL)2]·6CH3OH·2H2O (4) (H4L = 3-((1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylimino)methyl)-2-hydroxy-5-methylbenzaldehyde and H3L′ = 3-(4,4-bis(hydroxymethyl)oxazolidin-2-yl)-2-hydroxy-5-methylbenzaldehyde) have been successfully synthesized by a one-pot route at room temperature. The in situ polydentate ligands reveal various coordination modes in forming compounds 1–4. Structure analysis reveal that all four compounds have a centrosymmetric “parallelogram” core, where four μ3-CH2O– arms are linked on both sides of the Ln4 plane in compounds 1–3, while two μ3-CH2O– arms connected Dy4 in compound 4. In addition, magnetic susceptibility studies reveal that compound 4 shows single-molecule magnet (SMM) behaviour with a high-temperature energy barrier of 50.2 K and a low-temperature energy barrier of 4.5 K. The relaxation behaviour is probably attributed to the individual Dy ions and the magnetic coupling between neighboring Dy ions.