Lanthanide Isophthalate Metal‐Organic Frameworks: Crystal Structure, Thermal Behavior, and White Luminescence

Abstract

Two novel lanthanide metal-organic frameworks (LnMOFs), Ln 1.14 Na 0.57 (BDC) 2 (H 2 O) • 4H 2 O (Ln=La 3 + or Ce 3 + , BDC : 1,3-benzenedicarboxylate), have been synthesized under hydrothermal conditions by using a Ln 3 + coordination polymer as precursor. The crystal structure was determined from single crystal X-ray diffraction. Both compounds are isostructural and contain chains of face-sharing [LnO 10 ] polyhedra connected by the linkers to form an anionic three-dimensional network, defining both polar and apolar channels, the latter being occupied by water molecules and Ln 3 + and Na + cations. When doped by optimized content of Eu 3 + and Tb 3 + , the La 3 + counterpart exhibits white luminescence emission with CIE parameters equal to (0.3440, 0.3735) at λ exc = 321 nm, which renders the material attractive for white LED application.

Microwave-assisted synthesis to prepare metal-organic framework for luminescence thermometry

“…The system was investigated for three different temperatures, 150, 160 and 170°C, and for four synthesis durations (5, 15, 30 and 60 min) (Figure 2). For a temperature of 150°C and whatever the synthesis time, the obtained phase corresponds to the precursor already reported in our previous work, [29] which actually is the initial white precipitate that one formed by adding the cationic solution to the basic solution of ligand. At 160°C, the LaMOF material is obtained only for a synthesis time of 60 min, for lower duration a mixture with precursor is obtained.…”

“…The doped LaMOF material, namely LaMOF-5Eu-5Tb and LaMOF-7Eu-3Tb, where also prepared by microwave-assisted hydrothermal route at 170°C but the time duration was increased to 15 min to get pure phase. Both PXRD analysis (Figures S1 and S2) and FT-IR spectroscopy (Figure S3) confirmed the mixed Eu-Tb compounds are isostructural to undoped LaMOF [29].…”

“…The compound LaMOF crystallizes in the tetragonal apolar space group P42212. [29] In the network, each La 3+ cation is coordinated by ten oxygen atoms, eight oxygen atoms arising from the two different carboxylate groups and two oxygen atoms from water molecules in a distorted bicapped square prismatic environment. The LaO10 coordination polyhedra are connected by a triangular face along the c axis to form infinite chains.…”

“…To pursue our investigation of the role of inorganic network in LnMOFs on the thermometric properties while maintaining the same organic ligand, we herein investigate a new LnMOF that we recently discovered, namely Ln1.14Na0.57(BDC)2(H2O)4H2O (Ln = La, or Ce). [29] In this material, the inorganic network is composed by LnO10 polyhedra connected to form infinite chains linked by the organic linkers. Moreover, the crystal structure exhibits non-polar and polar channels, the latter one being filled by Ln 3+ and Na + cations.…”

Bifunctional color-tuning luminescent Ln@Zr-MOFs for white LEDs and sensitive, ultrafast detection of nitrobenzene in aqueous media

“…1b, it can also be found that Zr-MOFs and Eu 5 @Zr-MOFs have almost the same vibrational absorption peaks as UiO-66, except the absorption peak at 1715 cm −1 from the CO stretching vibration of free carboxylate groups. 27,28 During the formation of Zr-MOFs, H 2 BDC ligands were replaced partially by m -H 2 BDC ligands with the free and active –COOH groups. The presence of unreacted and bare –COOH groups in Zr-MOFs leads to more pronounced absorption peaks at 1715 cm −1 than in UiO-66.…”