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Abstract Two novel lanthanide metal-organic frameworks, namely {[Ln 2 (NSBPDC) 3 (H 2 O) 4 ]·x(H 2 O)} n (Ln = Eu 1 , Tb 2), have been facilely synthesized with 6-nitro-2,2'-sulfone-4,4'-dicarboxylic acid (H 2 NSBPDC). Structural analyses revealed that the two complexes are both three-dimensional (3D) non-interpenetrating networks based on infinite rod-shaped LnIII carboxylate SBUs and exhibit 1D channels decorated with functional groups. Fluorescence measurements show that complex 1 can serve as a fast and recyclable fluorescence sensor for nitroaromatics detection via a turn-off response with low detection limits. The fluorescence quenching of 1 for nitroaromatics is presumably due to the following two reasons: the photo-induced electronic transfer mechanism and the competitive adsorption mechanism. Graphical abstract Two novel Ln-MOFs (1 and 2) containing microporous channels decorated with functional groups have been synthesized. Complex 1 can serve as a fast and sensitive fluorescence sensor for detecting trace amount of nitroaromatics(NACs) fx1 Highlights • Two new Ln-MOFs (1 and 2) based on rod-shaped Ln carboxylate SBUs were synthesized. • 1 and 2 are 3D networks containing 1D channels decorated with functional groups. • 1 can serve as a fluorescence sensor for rapid detection of nitroaromatics. [ABSTRACT FROM AUTHOR]

Graphical abstract Two rhombus-shaped Dy 4 clusters with similar structures have been obtained. Magnetic analysis revealed different single-molecule magnet (SMM) behaviors occurs in 1 and 2 , which originated from the two slightly different β-diketonate (Htmhd and Hacac). Abstract In search of simple approaches to rationally modulate the single-molecule magnet behaviors in polynuclear lanthanide clusters, a new system containing two structurally closely related rhombus-shaped Dy 4 clusters, Dy 4 (tmhd) 4 L 6 (μ 3 -OH)2 ·5CH 3 CN (1) and Dy 4 (acac) 4 L 6 (μ 3 -OH) 2 (2) (HL = 5-(4-ethyoxylbenzylidene)-8-hydroxylquinoline, Htmhd = 2,2,6,6-tetramethyl-3,5-heptanedione and Hacac = acetylacetonate), have been obtained by employing two dysprosium β-diketonate salts to react with a bidentate Schiff base ligand (HL). The two Dy 4 clusters have similar structures and possess a structure in which four Dy3+ ions remain in a perfect plane with a rhombus-shaped geometric construction. Dynamic magnetic analysis revealed different single-molecule magnet (SMM) behaviors occurs in 1 and 2. Under zero direct-current (dc) field, 1 displays typical SMMs behavior with Δ E / k B = 39.6 K and τ 0 = 2.1 × 10−6 s. However, for 2 , a peculiar feature of the χ ″ versus temperature curves is that more than two peaks that are frequency-dependent are revealed, indicating the occurrence of multifold relaxation processes that lead to two Δ E / k B (31.3 K and 81.6 K) and pre-exponential factors (τ 0 = 3.1 × 10−6 s, τ 0 = 2.2 × 10−7 s). [ABSTRACT FROM AUTHOR]

Two new tetranuclear Ln-based clusters, namely [Ln 4 ( μ 3 -OH) 2 L 6 (beac) 4 ] (Ln = Gd ( 1 ) and Dy ( 2 )), were successfully assembled by employing 5-(2-thenylidene)-8-hydroxylquinoline (HL) and 1-benzoylacetone (Hbeac). They were structurally characterized by single crystal X-ray diffraction. In 1 ·Gd and 2 ·Dy, the structures of them are very similar with planar [Ln 4 O 2 ] cluster at the center, four Ln(III) ions in which are further coordinated by six L − and four beac − anions in the modes of μ 2 -η 2 η 1 for L − and μ 2 -η 2 η 1 for beac − , respectively. Additionally, the magnetic measurement of them reveal that 1 ·Gd displays magnetic entropy change (−Δ S m ) of 21.55(3) J K −1  kg −1 at 2 K for Δ H  = 7 T. For 2 ·Dy, it exhibits slow magnetic relaxation behavior with the energy barrier (Δ E / k B ) of 27.96(7) K. [ABSTRACT FROM AUTHOR]