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A family of novel lanthanide-based metal–organic frameworks (Ln-MOFs) with bifunctional fluorescence sensing properties, namely, {[(CH3)2NH2]5[Ln5(TBAPy)5]·solvent}n (Ln = Gd (1), Tb (2), and Dy (3); H4TBAPy = 1,3,5,7-tetra(4-carboxybenzene)pyrene), was synthesized and structurally characterized. Structural analysis reveals that Ln-MOFs1–3 are isomorphic, and Gd-MOF1 has a three-dimensional structure with a porosity of 20.40%. Due to the existence of the pyrene ring featuring a conjugated system, Ln-MOFs1–3 exhibit strong fluorescence emission. Interestingly, Ln-MOFs1–3 could be considered as good bifunctional fluorescence sensors toward acetylacetone and aspartic acid via a turn-on effect. The detection limits of Tb-MOF2 toward acetylacetone and aspartic acid are 0.129 and 0.025 ppm, respectively. Furthermore, the probable sensing mechanisms for target analytes were also discussed in detail. [ABSTRACT FROM AUTHOR]

Two new ZnII–LnIII heterometallic complexes derived from the amine-phenol ligand, namely [Zn2Ln(L)2(H2O)2](ClO4)3·3.5H2O (Ln = Dy (1) and Tb (2), H2L = 1,2-bis(3-methoxysalicylideneethylaminooxy)ethane), have been synthesized and structurally characterized. Complexes 1 and 2 are isomorphic trinuclear clusters and crystallize in the triclinic P1¯ space group. Magnetic measurements indicate that complex 1 exhibits field-induced slow magnetic relaxation with energy barrier of 27.91 K. Both display strong fluorescence emissions, which are typical narrow emission bands of lanthanide ions. Moreover, complex 2 shows a proton conductivity of 6.43 × 10−5 S cm−1 at 60 °C and 98% relative humidity. Complexes 1 and 2 as multifunctional materials may offer a potential application in magnetic, luminescent, and electrical devices. [ABSTRACT FROM AUTHOR]

A family of new TbIII and 3d–TbIII cluster complexes, namely [Tb(L)(CH3COCH3)] (1), [Tb2(μ-H2O)(L)2] (2), [Zn2Tb(L)2]·ClO4 (3) and [Ni2Tb(L)2]·ClO4 (4) (H3L = N,N′,N′′-tris(3,5-dimethyl-2-hydroxybenzyl)-1,4,7-triazacyclononane), have been synthesized through the reaction of H3L and metal salts. Structural analysis reveals that 1 and 2 exhibit mononuclear and binuclear structures, respectively, and both 3 and 4 exhibit trinuclear 3d–4f–3d structures. Interestingly, complex 1 could undergo reversible transformation to complex 2 by adjusting the reaction solvents. The alternating current (ac) magnetic susceptibilities of 3 reveal that out-of-phase (χ′′) is frequency- and temperature-dependent, which is a typical feature of field-induced slow magnetic relaxation with an energy barrier of 35.71 K. Moreover, complexes 1–3 show strong oxygen-sensitive luminescence, with typical narrow emission bands of lanthanide ions. The luminescence intensity and lifetime (5D4 of TbIII) of 3 are obviously stronger than those of 1 and 2. Therefore, complex 3 can be considered as a good candidate as a bi-functional magneto-luminescent molecular material. [ABSTRACT FROM AUTHOR]