Selectively detecting toluene and benzaldehyde by two stable lanthanide-organic frameworks as luminescent probes.

Benzene derivatives are seriously harmful to environment and human health, and sensitively detecting these compounds is of great significance but is a challenge. Hence, we designed and synthesized two luminescent lanthanide-organic frameworks, [{Ln(SIP)(H2O)4}]n, [Ln = Tb (1), Eu (2)], with high solvent and pH stability, which can be used as luminescent probes to detect toluene and benzaldehyde among various reagents, and the detection limit can reach up to 10-7 mol L-1 for toluene, and 10-6 mol L-1 for benzaldehyde. Regenerated experimental results indicate that both 1 and 2 can be used for at least five cycles with high precision. To the best of our knowledge, this is the first example of the two-dimensional regenerable luminescent sensor for toluene and benzaldehyde through luminescent quenching.

Assembly of single molecular magnets from dinuclear to 2D Dy-compounds with significant change of relaxation energy barriers.

A dinuclear Dy(III) compound (1) was structurally and magnetically characterized, displaying a single-molecule magnet (SMM) behavior with a relaxation energy barrier of 21(1) K. Interestingly, by only adding a suitable substituent on the ligand in , as an SMM building unit, can be further assembled into a two-dimensional (2D) framework (2), which possesses a typical SMM behavior and a high relaxation energy barrier of 68(2) K. The result implied that the assembly of an SMM can effectively tune the energy barrier. To our knowledge, a cluster-based SMM assembled into a new 2D framework with SMM behavior is seldom reported.

Controlled lanthanide-organic framework nanospheres as reversible and sensitive luminescent sensors for practical applications.

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.

Genetic diversity and haplotype structure of 24 Y-chromosomal STR in Chinese Hui ethnic group and its genetic relationships with other populations.

In the present study, 24 Y-chromosomal short tandem repeat (Y-STR) loci were analyzed in 115 unrelated Hui male individuals from Haiyuan county or Tongxin county, Ningxia Hui Autonomous Region, China, to evaluate the forensic application of the 24 STR loci and to analyze interpopulation differentiations by making comparisons between the Hui group data and previously published data of other 13 populations. A total of 115 different haplotypes were observed on these 24 Y-STR loci. The gene diversities ranged from 0.4049 (DYS437) to 0.9729 (DYS385a, b). The overall haplotype diversity was 1 at AGCU 24 Y-STR loci level, while the values were reduced to 0.999237, 0.996949, and 0.996644 at the Y-filer 17 loci, 11 Y-STR loci of extended haplotype and 9 Y-STR loci of minimal haplotype levels, respectively; whereas, haplotype diversity for additional 7 loci (not included in Y-filer 17 loci) was 0.995271. The pairwise FST , multidimensional scaling plot and neighbor-joining tree indicated the Hui group had the closest genetic relationship with Sala in the paternal lineage in the present study. In summary, the results in our study indicated the 24 Y-STRs had a high level of polymorphism in Hui group and hence could be a powerful tool for forensic application and population genetic study.

New strategy to construct single-ion magnets: a unique Dy@Zn6 cluster exhibiting slow magnetic relaxation.

Two unique heptanuclear clusters Ln@Zn6 (Ln = Dy (1), Er (2)) were structurally and magnetically characterized. Each Dy(3+)/Er(3+) is located in a nona-coordinate D(3h) coordination environment, and is encapsulated in a diamagnetic Zn6 cage. Compound 1 exhibits single-ion magnetic behavior, and is the first example of a single-ion magnet (SIM) constructed through embedding one magnetic anisotropic metal ion into a diamagnetic cage.

Structures, luminescent and magnetic properties of a series of (3,6)-connected lanthanide-organic frameworks.

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.

Unique (3,12)-connected coordination polymers displaying high stability, large magnetocaloric effect and slow magnetic relaxation.

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.

Structures, luminescent and magnetic properties of six lanthanide-organic frameworks: observation of slow magnetic relaxation behavior in the DyIII compound.

Six novel three-dimensional (3D) lanthanide metal-organic frameworks (LnMOFs), {[Ln(2)(ispc)(3)(H(2)O)(3)]·mH(2)O}(n) (Ln = Pr (1, m = 5); Eu (2, m = 5); Gd (3, m = 4); Tb (4, m = 5); Dy (5, m = 5) and Ho (6, m = 4)), ispc = 3-(4-carboxyphenylsulfonyloxy)-4-methoxybenzoic anion) have been synthesized under hydrothermal conditions. Single crystal X-ray diffraction revealed they are isostructural and crystallize in the triclinic crystal system, space group P1[combining macron]. The investigations on luminescent properties and lifetimes of 2 (Eu(III)), 4 (Tb(III)), and 5 (Dy(III)) exhibit characteristic emissions of Eu(III), Tb(III) and Dy(III) ions and the corresponding luminescent lifetimes are 0.14 ms, 9.93 µs and 1.25 ms, respectively. The different luminescent intensities and lifetimes among them were further discussed. Furthermore, magnetic studies of 1-6 reveal that 3-6 exhibit ferromagnetic coupling, and 5 (Dy(III)) exhibits remarkably slow magnetic relaxation behavior with the energy barrier ΔE/k(B) = 49.2 K.

Structural diversity and magnetic properties of five copper-organic frameworks containing one-, two-, and three-types of organic ligands.

Five novel compounds {[Cu(CMA)]·0.8H(2)O}(n) (1), {[Cu(CMA)(bpy)(0.5)]·0.5DMF}(n) (2), {[Cu(CMA)(bpy)(H(2)O)]·0.5H(2)O}(n) (3), {[Cu(2)(CMA)(DPA)(bpy)(2)(H(2)O)]ClO(4)}(n) (4) and {[Cu(3)(CMA)(DPA)(bpy)(4)(OH)](ClO(4))(2)·3H(2)O)}(n) (5) (H(2)CMA = 3-(carboxymethoxy)-5-methylbenzoic acid, HDPA = 2-(3,5-dimethylphenoxy)acetic acid, bpy = 4,4'-bipyridine) were synthesized and characterized by single crystal X-ray diffraction. Interestingly, the kinds of ligands included in these compounds are different: 1 contains single-ligand CMA(2-); 2 and 3 comprise two kinds of ligands (CMA(2-) and bpy); 4 and 5 cover three kinds of ligands (CMA(2-), DPA(-) and bpy). Structural analyses reveal that 1-3, and 5 are three-dimensional (3D) frameworks, while 4 is a 2D layer. Noteworthily, 1 possesses two types of channels: six-star and hexagonal ones. 3 displays a three-fold interpenetrating 3D framework. The structural diversity of the compounds may have originated from different anions, solvents and temperatures. Variable-temperature magnetic susceptibility measurements were carried out on compounds 1, 2 and 4, and the magnetic properties are dramatically different due to the structural diversities. The magnetic data of 1 shows an antiferromagnetic interaction with J = -54.84 cm(-1) estimated from the Bonner-Fisher model. The magnetic data of 2 was least-square fitted to the Blenaey-Bowers equation with J = -131.01 cm(-1), indicating the existence of a strong antiferromagnetic interaction between two adjacent Cu(2+). The magnetic data of linear tetranuclear structure 4 was best fitted to the expression derived from the Hamiltonian H = -2(2J(1)S(1)S(2) + J(2)S(1)S(1*)). The best fitting parameters are J(1) = -17.48 cm(-1) and J(2) = -65.26 cm(-1), which also indicate an antiferromagnetic interaction. Simultaneously, the magneto-structural relationship was discussed.

Fast capture and separation of, and luminescent probe for, pollutant chromate using a multi-functional cationic heterometal-organic framework.

We present one 3D cationic MOF (1-ClO(4)), which exhibits high thermal stability and strong alkali resistance. More importantly, it displays fast, selective capture of, and acts as a luminescent probe for, pollutant CrO(4)(2-) by anion exchange. Additionally, 1-ClO(4) exhibits interesting slow magnetic relaxation behavior at low temperature.