Luminescent and Magnetic Tb-MOF Flakes Deposited on Silicon

The synthesis of a terbium-based 2D metal–organic framework (MOF), of formula [Tb(MeCOO)(PhCOO)₂] (1), a crystalline material formed by neutral nanosheets held together by Van der Waals interactions, is presented. The material can be easily exfoliated by sonication and deposited onto different substrates. Uniform distributions of Tb-2D MOF flakes onto silicon were obtained by spin-coating. We report the luminescent and magnetic properties of the deposited flakes compared with those of the bulk. Complex 1 is luminescent in the visible and has a sizeable quantum yield of QY = 61% upon excitation at 280 nm. Photoluminescence measurements performed using a micro-Raman set up allowed us to characterize the luminescent spectra of individual flakes on silicon. Magnetization measurements of flakes-on-silicon with the applied magnetic field in-plane and out-of-plane display anisotropy. Ac susceptibility measurements show that 1 in bulk exhibits field-induced slow relaxation of the magnetization through two relaxation paths and the slowest one, with a relaxation time of τ_lf ≈ 0.5 s, is assigned to a direct process mechanism. The reported exfoliation of lanthanide 2D-MOFs onto substrates is an attractive approach for the development of multifunctional materials and devices for different applications.

A Multifunctional Dysprosium-Carboxylato 2D Metall-Organic Framework

We report the microwave assisted synthesis of a bidimensional (2D) MOF of formula [Dy(MeCOO)(PhCOO)₂ ]_n (1) and its magnetically diluted analogue [La_0.9 Dy_0.1 (MeCOO)(PhCOO)₂ ] (1 d). 1 is a 2D material with single-ion-magnet (SIM) behaviour and 1 d is a multifunctional, magnetic and luminescent 2D material. 1 can be exfoliated into stable nanosheets by sonication.

Rare-earth metal–organic frameworks: from structure to applications

In the past 30 years, rare-earth metal–organic frameworks (MOFs) have been gaining attention owing to their diverse chemical structures, and tunable properties.

Field-Induced Relaxation of Magnetization in a Three-Dimensional LnMOF with the Second Bridging Ligand Squarate

A three-dimensional (3D) dysprosium(III) metal-organic framework with nicotinate N-oxide (NNO^-) and squarate (C₄O₄ ^2-) mixed bridging ligands, [Dy(NNO)(C₄O₄)(H₂O)] _n (1), has been hydrothermally synthesized. The dysprosium(III) ions are linked to each other by the squarate anions to form a unique dysprosium(III) squarate double-layered network; the NNO^- anions then bridge such layers to complete the 3D framework. Complex 1 exhibits a two-step relaxation of magnetization under a dc field of 1000 Oe, with effective energy barrier values of 8.5 and 14.3 K, respectively.

A 3D MOF constructed from dysprosium(iii) oxalate and capping ligands: ferromagnetic coupling and field-induced two-step magnetic relaxation

Field-induced two-step magnetic relaxation was observed in the first ferromagnetic 3D lanthanide(iii) oxalate framework with a capping ligand.

Multiple thermal magnetic relaxation in a two-dimensional ferromagnetic dysprosium(iii) metal–organic framework

Intramolecular ferromagnetic interaction exists in a dysprosium(iii) MOF with a highly ordered 2D (4, 4) grid network, showing two-step thermal magnetic relaxation.

Two- and three-dimensional lanthanide-based coordination polymers assembled by the synergistic effect of various lanthanide radii and flexibility of a new binicotinate-containing ligand: in situ synthesis, structures, and properties

The design and synthesis of ten novel coordination polymers was investigated. They have three structural types from 3D to 2D due to the synergistic effect of lanthanide contraction with diverse coordination modes and conformations of the ligand.

Luminescence and slow magnetic relaxation of isostructural 2D lanthanide metal–organic frameworks derived from both nicotinate N-oxide and glutarate

The isostructural 2D lanthanide coordination polymers may exhibit either luminescence or slow magnetic relaxation, depending on the lanthanide ions.

Slow magnetic relaxation of a three-dimensional metal–organic framework featuring a unique dysprosium(iii) oxalate layer

Two-step thermal magnetic relaxation was observed in a novel three-dimensional dysprosium(iii) metal–organic framework.

Magnetic and luminescent properties of lanthanide coordination polymers with asymmetric biphenyl-3,2′,5′-tricarboxylate

An asymmetric ligand was employed to construct eight (3,6)-connected lanthanide complexes exhibiting slow magnetization relaxation behaviour and characteristic luminescent properties.

A 2D → 2D polyrotaxane lanthanide–organic framework showing field-induced single-molecule magnet behaviour

An entangled Dy(iii) MOF with both polyrotaxane and polycatenane features was prepared, displaying two-step magnetic relaxation processes.