Design and synthesis of a family of 1D-lanthanide-coordination polymers showing luminescence and slow relaxation of the magnetization

Abstract

We have designed and synthesized eight isostructural 1D coordination polymers (CPs) with the general formula {[Ln(aapc)3(DMF)]}n [where Ln(iii) = Y (2), La (3), Nd (4), Eu (5), Gd (6), Tb (7), Dy (8), Er (9); and aapc = 3-((anthraquinone-1-yl)amino)propanoate]. These CPs consist of Ln-carboxylate infinite rods in which the bulky anthraquinone scaffolds arise from it in such a way that the resulting supramolecular packing exhibits isolated 1D chains. Solution structures have been corroborated through NMR methods including PGSE and EXSY NMR studies and, due to the presence of lanthanide ions, magnetic and luminescence properties have been studied. Alternating current magnetic measurements of compound 8 show slow relaxation of the magnetization, a characteristic of single molecule magnets (SMMs). The evaluation of solid-state photophysical properties reveals that the aapc scaffold sensitizes lanthanide(iii) based emission of compounds 4-9 both in the visible and near-infrared (NIR) regions at 10 K.

Exploring the Slow Magnetic Relaxation of a Family of Photoluminescent 3D Lanthanide–Organic Frameworks Based on Dicarboxylate Ligands

“…In particular, a main multiplet is shown at 1060 nm (structured into two main narrow peaks) in addition to a weak and wider band peaking at ca. 1345 nm is shown for 1, which is in good agreement with usually observed signals for the Nd(III)-based compounds [68,69]. On its part, compound 4 presents a main manifold located at ca.…”

Octahedral Hexachloro Environment of Dy3+ with Slow Magnetic Relaxation and Luminescent Properties

“…6 H 11/2 transitions of Dy 3 + ion, respectively. [52] The intense band at 574 nm is responsible of the yellow emission color of the compound. The peak expected for the 4 F 9/2 !…”

Cadmium-Inspired Self-Polymerization of {LnIIICd2} Units: Structure, Magnetic and Photoluminescent Properties of Novel Trimethylacetate 1D-Polymers (Ln = Sm, Eu, Tb, Dy, Ho, Er, Yb)

“…The choice of Ln III compounds for this study was caused by the unique properties of such ions, i.e., their ability to exhibit slow magnetic relaxation (the so-called Single-Molecule Magnetism, SMM, or Single Ion Magnetism, SIM) [ 21 ] along with luminescence [ 22 ]. A lot of coordination polymers, containing only Ln III ions as paramagnetic centers, exhibit SMM properties (in particular, slow relaxation of magnetization) [ 23 , 24 , 25 ], however, in many cases, the role of the exchange coupling between Ln III ions (if any) in the occurrence of SMM properties was not clear. In some cases, it was shown that exchange interactions between paramagnetic ions can facilitate magnetic relaxation via the mechanism of quantum tunneling of magnetization (QTM) [ 26 ], but the opposite effect was also found: QTM was quenched due to the Cr III ···Dy III coupling compared to the analog containing diamagnetic Co III [ 27 ].…”

“…In some cases, it was shown that exchange interactions between paramagnetic ions can facilitate magnetic relaxation via the mechanism of quantum tunneling of magnetization (QTM) [ 26 ], but the opposite effect was also found: QTM was quenched due to the Cr III ···Dy III coupling compared to the analog containing diamagnetic Co III [ 27 ]. More interesting effects were found for magnetically diluted Ln complexes, characterized by slow magnetic relaxation [ 23 , 28 ]. In addition, long-range magnetic ordering was found in the Ln III coordination polymers [ 29 ].…”