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Entacapone (ENT) is a powerful catechol‐O‐methyl transferase inhibitor that is used for the diagnosis and treatment of Parkinson's syndrome, but the amount used must be well controlled to avoid overtreatment and side effect. Fast and selective detection of ENT needs well‐matched energy levels and well‐designed sensor‐ENT interaction which is highly challenging. In this work, a water stable europium‐based metal‐organic framework (Eu‐TDA) was synthesized to detect ENT by luminescence with excellent reusability and selectivity in the presence of main coexisting and interference species of plasma with a limit of detection of 5.01 μM. The experimental results showed that the luminescence of Eu‐TDA can be effectively quenched by ENT via well‐designed photoinduced electron transfer mechanism and internal filtration effect mechanism in the system. [ABSTRACT FROM AUTHOR]

Abstract: Increasing both the energy barrier for magnetization reversal and the coercive field of the hysteresis loop are significant challenges in the field of single‐molecule magnets (SMMs). Coordination geometries of lanthanide ions and magnetic interactions between lanthanide ions are both important for guiding the magnetic behavior of SMMs. We report a high energy barrier of 657 K (457 cm−1) in a diamagnetic‐ion‐diluted lanthanide chain compound with a constrained bisphenoid symmetry (D2d); this energy barrier is substantially higher than the barrier of 567 K (394 cm−1) of the non‐diluted chain compound with intrachain ferromagnetic interactions. Although intrachain magnetic interaction lowers the energy barrier for magnetization reversal, it can greatly enhance the coercive fields and zero‐field remanence of the hysteresis loops, which is crucial for the rational design of high‐performance SMMs. Factors related to the coordination sphere of the lanthanide center, which govern the high magnetic relaxation barriers through the second excited Kramer's doublets and the magnetic interactions that affect the hysteresis loops, were revealed through ab initio calculations. [ABSTRACT FROM AUTHOR]

Luminescent 3D lanthanide metal-organic framework (Ln-MOF) {[Tb2(TATAB)2] ⋅4 H2O ⋅6 DMF} n ( 1) was synthesized under solvothermal conditions by using flexible ligand 4,4′,4′′- s-triazine-1,3,5-triyltri- p-aminobenzoate (TATAB). A phase transition was observed between low temperature and room temperature. The luminescence of 1 could be enhanced by formaldehyde and quenched efficiently by trace amounts of benzaldehyde in solvents such as benzyl alcohol (0.01-2.0 vol %) and ethanol (0.01-2.5 vol %). This is the first use of a Ln-MOF as chemical sensor for both formaldehyde and benzaldehyde. The high sensitivity and selectivity of the luminescence response of 1 to benzaldehyde allows it to be used as an excellent sensor for identifying benzaldehyde and provides a simple and convenient method for detecting traces of benzaldehyde in benzyl alcohol based injections. This work establishes a new strategy for detection of benzaldehyde in benzyl alcohol by luminescent MOFs. [ABSTRACT FROM AUTHOR]

A series of six-coordinate lanthanide complexes {(H3O)[Ln(NA)2]⋅H2O} n (H2NA=5-hydroxynicotinic acid; Ln=GdIII ( 1⋅Gd); TbIII ( 2⋅Tb); DyIII ( 3⋅Dy); HoIII ( 4⋅Ho)) have been synthesized from aqueous solution and fully characterized. Slow relaxation of the magnetization was observed in 3⋅Dy. To suppress the quantum tunneling of the magnetization, 3⋅Dy diluted by diamagnetic YIII ions was also synthesized and magnetically studied. Interesting butterfly-like hysteresis loops and an enhanced energy barrier for the slow relaxation of magnetization were observed in diluted 3⋅Dy. The energy barrier (Δ τ) and pre-exponential factor ( τ0) of the diluted 3⋅Dy are 75 K and 4.21×10−5 s, respectively. This work illustrates a successful way to obtain low-coordination-number lanthanide complexes by a framework approach to show single-ion-magnet-like behavior. [ABSTRACT FROM AUTHOR]