A Series of Lanthanide Metal–Organic Frameworks with Interesting Adjustable Photoluminescence Constructed by Helical Chains

Abstract

Based on the isonicotinic acid (HIN=pyridine-4-carboxylic acid), seven lanthanide metal-organic frameworks (MOFs) with the formula [Ln(IN)2 L] (Ln=Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7), L=OCH2 CH2 OH) have been synthesized by mixing Ln2 O3 with HIN under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, and fluorescence spectroscopy. Crystal structural analysis shows that compounds 1-6 are isostructural, crystallize in a chiral space group P21 21 21 , whereas compound 7 crystallizes in space group C2/c. Nevertheless, they all consist of new intertwined chains. Simultaneously, on the basis of the above-mentioned compounds, we have realized a rational design strategy to form the doped Ln MOFs [(Eux Tb1-x )(IN)2 L] (x=0.35 (8), x=0.19 (9), x=0.06 (10)) by utilizing Tb(III) as the second "rare-earth metal". Interestingly, the photoluminescence of [(Eux Tb1-x )(IN)2 L] are not only adjustable by the ratios of Eu/Tb, but also temperature or excitation wavelength.

Two Pairs of Chiral “Tower‐Like” Ln4Cr4 (Ln=Gd, Dy) Clusters: Syntheses, Structure, and Magnetocaloric Effect

“…Bond lengths of GdÀO range from 2.307(7) to 2.753(11) ,y et O-Gd-O angles are between 58.8(5)a nd 148.7(2)8,w hich is consistentw ith the documentedl iterature. [13] However,t he bond lengths of DyÀOa re between 2.291(8) and 2.495(11) ,w hereas O-Dy-Oa ngles are 66.2(3)-147.3(4)8 and in lie within the ranges in past literature reports. [14] In terms of coordination environments, on the one hand, there exits two coordination environments for Gd 3 + ions.…”

Preparation of Composite Filters Based on Porous Coordination Polymers by Using a Vacuum Filtration Method for Highly Efficient Removal of Particulate Matters

“…And the adjacent chains could be further connected alternately into 1D doublechains via O-H···Oh ydrogen bond interactions with the distance about 1.968 (Figure2b). [26] Moreover,there also existed p···p interactions between the adjacent double-chains, which were further linked the double-chains into a2 Dl ayer (Figure 2d). Adjacent 2D layers were able to link with each other via another p···p stacking interactions,forming a3Dframework (Figure 2c,e), which could be simplified to 6-connected pcu topology network ( Figure 2f).…”

Chirality and Magnetic Properties of One‐dimensional Ln (Ln = Gd, Dy) Polymers

“…As persistence of our researches on lanthanide compounds, lanthanide compounds were successfully obtained, [Ln(IN) 2 (L)] (Ln = Eu, Tb, Dy, Er, Ho, Gd, La; L = OCH 2 CH 2 OH), based on ligand‐controlled hydrolytic approach . Nowadays, our team without HCOOH and on shorter reaction time as well as lower reaction temperature than reported literature, successfully obtained l ‐ and d ‐{Dy[IN][HIN][CH 2 OCH 2 O]} n (Dy), as well l ‐ and d ‐{Gd[IN][HIN][CH 2 OCH 2 O]} n (Gd) (HIN = isonicotinic acid).…”

“…In the light of magnetic properties, the lanthanide ions, as evidenced by the rising research, have attracted plentiful attention on establishment both single‐chain magnets (SCMs) and single‐molecule magnets (SMMs) as well as magnetocaloric effect (MCEs),, on account of the magnetic anisotropy or the large‐spin multiplicity of the spin ground‐state , . To the best of our knowledge, lanthanide ions own the individual 4f electronic structures, resulting high and changing coordination numbers, large magnetic effects and so on, which is favored for the potential applications in magnetic fields, etc , . For example, Gd 3+ ion owns characteristic f 7 election framework and negligible magnetic anisotropy has been widely researched and regarded as a remarkable candidate for molecular magnetic refrigerant materials such as Gd 60 with –Δ S max = 48 J · kg –1 · K –1 and Gd 140 with –Δ S max = 38 J · kg –1 · K –1 , …”