Synthesis, Crystal Structures, and Luminescent Properties of Noninterpenetrating (6,3) Type Network Lanthanide Metal–Organic Frameworks Assembled by a New Semirigid Bridging Ligand

Abstract

A series of lanthanide metal-organic frameworks (MOFs) possessing 4f homometallic 2D noninterpenetrating (6,3) honeycomb topological network structures with lanthanide atoms acting as three-connected centers have been assembled by using a semirigid bridging ligand with lanthanide nitrates, namely [{Ln 2 (NO 3 ) 6 L 3 }·(H 2 O) 2 ·(CHCl 3 )] n (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er; L = 2,5-dimethyl-1,4-bis[{(2Ј-benzylaminoformyl)phenoxy}methyl]benzene. The coordination layers are linked by intermolecular hydrogen bonds to

Synthesis, Photoluminescence and Effect of Lanthanide Contraction on Structures of 3D Lanthanide‐Organic Frameworks from 1,4‐Benzenedicarboxylic Acid and Oxalic Acid

“…When compound 1 is excited at 275 nm, it exhibited characteristic emission bands for Tb 3+ centred at 490, 546, 586, and 622 nm, that belonging to the transitions of 5 D 4 → 7 F J ( J=6,5,4,3) (Figure b) . The 5 D 4 → 7 F 6 and 5 D 4 → 7 F 5 emissions result from an electric dipole transition and a magnetic dipole transition, respectively . The most intense emission is centered at 546 nm and corresponds to the hypersensitive 5 D 4 → 7 F 5 transition exhibiting a strong green luminescent emission.…”

Microwave-assisted Preparation, Structures, and Photoluminescent Properties of [Ln(NO3)2(H2O)3(L)2](NO3)(H2O) {Ln=Tb, Eu;L=2-(4-pyridylium)ethanesulfonate, (4-pyH)+-CH2CH2-SO3-}

“…The emission spectrum of complex 1 displays the characteristic transitions of 5 D 0 → 7 F n (n = 1-4) at 590, 615, 650, and 699 nm, which can be explained on the basis of the Eu 3+ energy-level structure. [31][32][33][34] The fact that no emission peaks other than the characteristic emission peaks of Eu 3+ ions appear in the emission spectrum indicates that a ligand-to-europium energy transfer is inefficient.…”

Luminescent Ultralong Microfibers Prepared through Supramolecular Self‐Assembly of Lanthanide Ions and Thymidine in Water

“…Strong stretching vibration transmittance bands at 1510 and 1384 cm −1 corresponded to free NO 3 − anions ( D 3 h ). However, no clear bands at 1280–1300 cm −1 belonging to coordinated NO 3 − ions ( V 4 ) were detected, indicating no NO 3 − anions coordinated to lanthanide ions groups . Compared to the ligand molecule thymidine, all the peaks in 1 H NMR spectra of Eu III /Tb III –T were broader due to the paramagnetic effect from the coordination interaction between thymidine and Eu III /Tb III ions (Figure D).…”

“…However,n oc learb ands at 1280-1300 cm À1 belonging to coordinated NO 3 À ions (V 4 )w ere detected,i ndicating no NO 3 À anions coordinated to lanthanide ions groups. [12] Compared to the ligand molecule thymidine, all the peaks in 1 HNMR spectra of Eu III /Tb III -T were broader due to the paramagnetic effect from the coordination interaction between thymidine and Eu III /Tb III ions ( Figure 3D). In addition, the chemicals hifts of the hydrogen atoms (at 4.9 and5 .2 ppm) in the Eu III /Tb III -T complexes were similart ot hymidine, suggesting that the hydroxylmethylene group on the furanose ring did not take part in the coordination of Eu III /Tb III cations.M oreover,w en oted that the signal of the hydrogen atom of the NÀHg roup sitting in between the carbonyl groups disappeared, in agreementw ith the FTIR data analysis; we proposed it might be due to the conversion of amide group into its isomer HOÀC=N-.…”