RESUMEN
A series of bifunctional Ln(III)-based coordination polymers (CPs) {Ln(L)(DMA)2(NO3)}n [Ln(III) = Eu (1), Gd (2), and Dy (3); organic ligand H2L = 2,2'-(1,3,5,7-tetrahydroxyoctahydro-4,8-ethanopyrrolo[3,4-f]isoindole-2,6(1H,3H)-diyl)diacetic acid)] have been successfully synthesized. CPs 1-3 are isostructural and constructed from the dimeric Ln2 unit in which two adjacent LnIII ions are bridged by two µ3-carboxyl oxygens, and the Ln2 dimeric unit is connected by two NO3- ions, four DMA molecules, and four completely protonated L2- ligands forming a 2D layer structure. The magnetic research reveals that CP 2 shows a significant cryogenic magnetocaloric effect (-ΔSm = 22.9 J kg-1 K-1; T = 2.0 K and ΔH = 7.0 T), whereas CP 3 exhibits slow magnetic relaxation property under Hdc = 0 Oe field. Additionally, the luminescence explorations revealed that CP 1 can act as a recyclable luminescent probe for pollutant acetylacetone among various small organic solvent molecules, and the corresponding detection limit is 10-7 mol/L. More importantly, CP 1 also exhibits good catalytic performance in the cycloaddition reaction of CO2 and epoxides or cyanamides under mild conditions. As far as we know, CP 1 represents the first bifunctional lanthanide homogeneous catalyst that can efficiently catalyze the reaction of cyanamides/epoxides with CO2 simultaneously.
RESUMEN
The Liulin Spring is one of the ten most famous karst springs in the Shanxi province. The abundant karst groundwater resources support the economic and social development in the Luliang Prefecture. Therefore, the study of evolution and control factors of karst groundwater is of great significance to the sustainable utilization of water resources in the watershed. For revealing the evolution and control factors of karst groundwater in the Liulin Spring area, the main ion components of 29 karst groundwater samples from spring supply area, runoff area, discharge area, and deep buried area were analyzed. The results showed that the temperature and Na+, Ca2+, Mg2+, Cl-, HCO3-, and SO42- concentrations increased continuously along the runoff route, from the recharge area to the runoff area, to the discharge area, and then to the deep burial area. K+, Na+, and Cl- mainly come from salt rock dissolution, and Ca2+, Mg2+, HCO3-, and SO42- mainly come from the dissolution of calcite, dolomite, and gypsum. Because they are controlled by the continuous dissolution of salt rock and gypsum, the concentration of Na+, Cl-, and SO42- in groundwater has increased greatly, with the maximum value being 50 times, 80 times, and 32 times of the minimum value, respectively. Under the influence of dedolomitization, the concentration of Ca2+ and HCO3- in groundwater does not change significantly, the maximum is 2-3 times of the minimum. In the recharge area and runoff area, Na+ and Cl- amounts are lower, and Ca2+ and HCO3- are the main cations and anions in the groundwater. However, in the discharge area and deep buried area, Cl- and Na+ exceed HCO3-, Ca2+, and Mg2+ and become the main anions and cations in the groundwater. The hydrochemical type changes from HCO3-Ca·Mg in the supply area to HCO3·SO4-Ca·Mg in the runoff area, to HCO3·SO4-Ca·Na·Mg in the recharge area, and finally to Cl·HCO3-Na·Ca, Cl·HCO3-Na, and Cl-Na·Ca in the deep burial area.
RESUMEN
A novel metal-organic framework {[Zn(XL)2 ](ClO4 )2 â 6 H2 O}n (XL=N,N'-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide bi(1,2,4-triazole)) was synthesized and structurally characterized, presenting the first example of six-fold interpenetrating 3 D framework with the topology type of sqc6, which displays high thermostability and solvent stability. Additionally, the luminescence investigations reveal that this MOF can sensitively and selectively detect acetylacetone with a detection limit of 1.72â ppm. More importantly, it is rather rare for an MOF-based luminescence probe to serve as a sensor to effectively detect acetylacetone.
RESUMEN
Two novel 3D frameworks were synthesized, and further nanosized to form nanospheres. Studies revealed that is the first MOF-based luminescent sensor for detecting cyclohexane, and this is also the first time that quick regeneration, high sensitivity, high yield, and easy nanocrystallization of MOF-based luminescent sensors have been simultaneously realized.
RESUMEN
Through hydrothermal reactions with corresponding lanthanide nitrates and 4-(4-carboxyphenylsulfonyloxy)-3-metnoxybenzoic acid (H2vspc), seven novel three-dimensional (3D) lanthanide-organic frameworks ([Ln(vspc)(Hvspc)(H2O)]n [Ln = Pr (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6) and Er (7)]) have been synthesized and structurally characterized. All of them are isostructural and crystallize in the monoclinic crystal system, P21/c space group. Their structures feature a (3,6)-connected topological network, in which Ln(3+) were connected by carboxylate groups to give a 1D lanthanide chain, and the adjacent chains are further spanned by vspc(2-) and Hvspc(-) anions to form a 3D framework. The luminescent properties and lifetimes of 2 (Eu(III)), 4 (Tb(III)), and 5 (Dy(III)) have been studied, and the corresponding luminescent lifetimes are 0.53, 0.99 and 0.014 ms, respectively. The magnetic investigations reveal that compound displays weak antiferromagnet interaction, 4 and 5 exhibit ferromagnetic coupling, and compound 5 exhibits slow magnetic relaxation behavior.
RESUMEN
Two unique 3D coordination polymers based on octahedral [Ln6] (Ln = Gd (), Dy ()) clusters as nodes were synthesized, exhibiting a novel (3,12)-connected topology with the symbol of (4(20)·6(26)·8(20))(4(3))4. The magnetic studies reveal that shows a -ΔSm = 46.6 J kg(-1) K(-1), falling among the largest values known to date, and displays slow magnetic relaxation behavior. Both and have high thermal and solvent stabilities.