In Situ Ligand Formation in the Synthetic Processes from Mononuclear Dy(III) Compounds to Binuclear Dy(III) Compounds: Synthesis, Structure, Magnetic Behavior, and Theoretical Analysis

Guided by the self-assembled process and mechanism, the strategy of in situ Schiff base reaction would be capable of bringing a feasible method to construct and synthesize lanthanide compounds with distinct structures and magnetic properties. A mononuclear Dy(III) compound was synthesized through a multidentate Schiff base ligand and a chelating β-diketonate ligand, which was named as [Dy(L)(bppd)]·CH₃OH [1; H₂L = N,N'-bis(2-hydroxy-5-methyl-3-formylbenzyl)-N,N'-bis(pyridin-2-ylmethyl)ethylenediamine and bppd = 3-bis(pyridin-2-yl)propane-1,3-dione]. Furthermore, a new binuclear Dy(III) compound, [Dy₂(H₂Lox)(bppd)₃]·8CH₃OH [2; H₄Lox = N,N'-bis[2-hydroxy-5-methyl-3-(hydroxyiminomethyl)benzyl]-N,N'-bis(pyridin-2-ylmethyl)ethylenediamine], was obtained via an in situ synthetic process. Under similar synthetic conditions, [Dy(L)(ctbd)] [3; ctbd = 1-(4-chlorophenyl)-4,4,4-trifluoro-1,3-butanedione] and [Dy₂(H₂Lox)(ctbd)₃]·CH₃OH·C₄H₁₀O (4) were synthesized by modifying the β-diketonate ligand and in situ Schiff base reaction. Compound 3 is a mononuclear configuration, while compound 4 exhibits a binuclear Dy(III) unit. Therein, formylbenzyl groups of H₂L in 1 and 3 were changed to (hydroxyiminomethyl)benzyl groups in 2 and 4, respectively. In isomorphous 2 and 4, two Dy(III) centers are connected through two phenol O^- atoms of the H₂Lox^2- ligand to form a binuclear structure. Eight-coordinated Dy(III) ions with different distortions can be observed in 1-4. The crystals of 1 and 3 suffered dissolution/precipitation to obtain 2 and 4, respectively. The relationship between the structure and magnetism in compounds 1-4 was discussed through the combination of structural, experimental, and theoretical investigations. Especially, the rates of quantum tunneling of magnetization of 1-4 were theoretically predicted and are consistent with the experimental results. For 2 and 4, the theoretically calculated dipolar parameters J_dip are consistent with the experimental observation of weak ferromagnetic coupling.

Effect of coordination geometry on the magnetic properties of a series of Ln2 and Ln4 hydroxo clusters

Tetra and di-nuclear Lanthanide hydroxo clusters have been synthesized and characterized magnetically.

The influence of an external magnetic field and magnetic-site dilution on the magnetization dynamics of a coordination network based on ferromagnetic coupled dinuclear dysprosium(iii) units

A 2D coordination network was synthesized and structurally characterized. Ferromagnetic interactions, multi-process slow relaxation of magnetization and hysteresis loops were also studied.

S-Functionalization of 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazine: probing the effect of alkyl chain length in the development of tethered materials

The preference of S-alkyl-thiatriazines towards intra vs. intermolecular addition is dependent on alkyl chain length, as demonstrated experimentally and computationally.

Boratriazines: inducing luminescence through boron incorporation into a terpy-type framework

The synthesis and physicochemical properties of pyridyl and pyrimidyl functionalized 1,3,5,2-triazaborinines are reported, along with the Lewis acid–base adduct pyrimidine-2-carboximidamide trifluoroborane, which forms as a side product in the reaction with the pyrimidyl substituents.

Construction of lanthanide single-molecule magnets with the “magnetic motif” [Dy(MQ)4]−

[Dy₂(MQ)₄(NO₃)₃]⁺ is SMM-silent (SMM = single-molecule magnet) owing to the unfavourable magnetic interactions. Introducing an additional “magnetic motif” [Dy(MQ)₄]⁻ to diminish such interactions gave a trinuclear [Dy₃(MQ)₈(NO₃)], which behaves as an SMM.

Half-sandwich lanthanide crown ether complexes with the slow relaxation of magnetization and photoluminescence behaviors

Four half-sandwich lanthanide crown ether complexes were successfully synthesized and structurally characterized. Dysprosium complexes show both the slow relaxation of magnetization and photoluminescence behaviors.

Synthesis, structures and magnetism of heterotrimetallic Ni–Cu–Ln complexes based on a dicompartmental imine–oxime ligand

Four Ni^II–Cu^II–Ln^III heterotrimetallic complexes have been prepared and structurally characterized. The Dy derivative behaves as a SMM with a small effective energy of 0.78 K under zero dc-applied field.

A propeller-shaped μ4-carbonate hexanuclear dysprosium complex with a high energetic barrier to magnetisation relaxation

A Dy₆ complex composed of two Dy₃ triangular units was isolated and found to exhibit slow relaxation of the magnetisation under zero applied dc field, resulting in a high energetic barrier to relaxation.

New sandwich-type lanthanide complexes based on closed-macrocyclic Schiff base and phthalocyanine molecules

Two new sandwich-type lanthanide complexes simultaneously containing closed-macrocyclic Schiff base and phthalocyanine molecules were synthesized and structurally characterized. The magnetic studies reveal the corresponding dysprosium complex behaves as a typical SMM.

Alkyl-functionalization of 3,5-bis(2-pyridyl)-1,2,4,6-thiatriazine

S-Alkyl-1,2,4,6-thiatriazines, which can be preparedviatwo pathways, are described. The regioselectivity and photophysical properties are rationalized through computational studies.