25458-13-3Relevant academic research and scientific papers
Synthesis, Crystal Structures, and Magnetic Properties of New Hexanuclear MnIII2LnIII4 Complexes: SMM Behavior of the Terbium(III) Analogue
Roy, Shuvayan,Ghosh, Sagar,Martins, Daniel O. T. A.,Tuna, Floriana,Mohanta, Sasankasekhar
, p. 5191 - 5202 (2018)
This investigation reports the syntheses, crystal structures, and magnetic properties of a series of isomorphous hexanuclear MnIII2LnIII4 compounds of composition [MnIII2LnIII4L12L22(μ3-OH)4(μ1,3-Pivalate)6(NO3)2]·2CH3CN {Ln = Tb (1), Dy (2), Ho (3), Er (4)}, where H2L1 is the Schiff base ligand that is obtained by [1+1] condensation of 3-methoxysalicylaldehyde (HL2) with 2-amino-2-methyl-1-propanol. While the O(phenoxo)N(imine)O(alkoxo) pocket of the ligand [L1]2– binds a MnIII ion, the other pocket, O(methoxy)O(phenoxo), remains noncoordinated. In contrast, each of the O(methoxy)O(phenoxo) and O(phenoxo)O(aldehyde) sites of [L2]– is occupied by a LnIII ion. Additionally, there are four μ3-hydroxo, six μ1,3-pivalate, and two chelating nitrate ligands, stabilizing the hexanuclear cores. Magnetic susceptibility (2–300 K) and magnetization (M) data reveal significant anisotropy in 1–4. Detailed ac susceptibility measurements have revealed single molecule magnet (SMM) behavior in the TbIII analogue with Ueff = 11.12 cm–1 and τ0 = 1.04 × 10–7 s under a 1000 Oe dc field and Ueff = 10.42 cm–1 and τ0 = 1.62 × 10–7 s under a 3500 Oe dc field, while the other three analogues do not show slow relaxation of magnetization.
Synthesis, Crystal Structures, Magnetic Properties, and Fluorescence of Two Heptanuclear CoIII4LnIII3 Compounds (Ln = GdIII, DyIII): Multiple Relaxation Dynamics in the DyIII Analogue
Roy, Shuvayan,Hari, Nairita,Mohanta, Sasankasekhar
, p. 3411 - 3423 (2019)
This report describes the synthesis, crystal structures, magnetic and spectroscopic properties of two heptanuclear CoIII4LnIII3 systems of composition [CoIII4GdIII3L4(μ4-O)2(μ-OMe)2(μ1,3-OAc)4(H2O)2(NO3)2]·NO3·2CH3OH·2H2O (1) and [CoIII4DyIII3L4(μ4-O)2(μ-OMe)2(μ1,3-OAc)4(H2O)2(NO3)2]·NO3·3CH3OH·1.5H2O (2), where H2L is [1+1] condensation product of 3-methoxysalicylaldehyde and 2-amino-2-methyl-1-propanol. The heptametallic cores in 1 and 2 may be taken as consisted of two symmetry related trinuclear CoIIILnIIICoIII moieties and a central lanthanide center in such a way that each of the three metal ions of each of the two trinuclear moieties are bridged with the central lanthanide through bridging oxo/alkoxo/acetate ligands. DC magnetic measurements of 1 and 2 reveal very weak GdIII···GdIII antiferromagnetic interaction (J = –0.01 cm–1) in 1 and significant anisotropy in 2. Variable-temperature and variable-frequency ac susceptibility measurements of 2 reveal that it is a zero-field SMM with multiple relaxation dynamics. Above 5 K, two well resolved relaxation channels are observed; Ueff and τ0 are 51.4 cm–1 and 9.40 × 10–7 s for the slow relaxation channel and 24.3 cm–1 and 6.91 × 10–7 s for the fast relaxation channel. The characteristic DyIII based transitions, 4F9/2→6H15/2, 4F9/2→6H13/2 and 4F9/2→6H11/2, can be well assigned in the fluorescence spectrum of 2 at solid state. All in all, compound 2 is a bifunctional molecular material.
