A highly hydrolytically stable lanthanide organic framework as a sensitive luminescent probe for DBP and chlorpyrifos detection.

Organic pollutants have attracted increasing attention due to their strong persistence and extensive diffusivity. Plasticizers (PAEs) and organophosphorus pesticides (OPs), as the vital part of organic pollutants, have made extensive damage to the environment with the rapid development of modern agriculture and industry. Therefore, we have, for the first time, carried out a quantitative analysis of the PAEs and OPs by fluorescence recognition. A series of isostructural lanthanide organic frameworks, [Ln(tftpa)1.5(2,2'-bpy)(H2O)] (Ln = Gd 1, Eu 2 and Tb 3, H2tftpa = tetrafluoroterephthalic acid), were hydrothermally synthesized, of which 3 exhibited excellent hydrolytic resistance to both boiling acidic and basic aqueous solutions. Moreover, luminescence investigations show that 3 can be used as a highly sensitive and recyclable luminescence sensor for the detection of DBP (di-n-butyl phthalate) in simulated seawater and chlorpyrifos in ethanol with the detection limits of 2.07 and 0.14 ppb, respectively.

Magnetic Tuning of an Anionic CoII -MOF through Deionization of the Framework: Spin-Canting, Spin-Flop, and Easy-Plane Magnetic Anisotropy.

An anionic CoII -MOF, (Me2 NH2 )[Co3 (Me2 NH)3 (OH)(SDBA)3 ] (1) (H2 SDBA=4,4'-sulfonyldibenzoic acid) consisting of highly symmetric CoII3 (µ3 -OH) triangles exhibits spin-canting, spin-flop, and easy-plane magnetic anisotropy. Measurement on a single crystal shows that the ab plane of 1 is the easy magnetization plane. After structural modification through simultaneous removal of the coordinated dimethylamine (DMA) molecule at the Co center and the ionic groups DMA+ and OH- , the resulting neutral amorphous framework 2 displays an enhanced spin frustration effect. The deionization of 1 does not result in the collapse of the framework, showing the high stability of the backbone structure.

Interpreted Recognition Process: A Highly Sensitive and Selective Luminescence Chemosensor.

A luminescence-sensing process based on coordination compound [H2 N(CH3 )2 ]3 [Tb(dipic)3 ] was developed. It shows fast response (within 1 min), high selectivity, and is ultrasensitive to detect Fe(3+) or Cr(3+) in aqueous solution and living cells (KSV values are calculated to be 3.6×10(4)  L mol(-1) for Fe(3+) and 1.9×10(4)  L mol(-1) for Cr(3+) ). The whole recognition process has been witnessed through electrospray ionization mass spectrometry (ESI-MS) analysis, and the ligand-transfer-induced luminescence-quenching mechanism is interpreted. This work contributes to extend the potential applications of lanthanide coordination compounds (LnCCs) in the fields of biological and environmental technologies.

Four new Mn(II) inorganic-organic hybrid frameworks with diverse inorganic magnetic chain's sequences: syntheses, structures, magnetic, NLO, and dielectric properties.

Four new inorganic-organic hybrid manganese frameworks, formulated as [Mn(Am-Hip)2]·3H2O (1), [Mn2(ip)2(H2O)]·CH3OH (2), [Mn2(OH-ip)2(DMF)]·DMF (3), and (Me2NH2)[Mn4(sdba)4(Hsdba)(H2O)]·3H2O·2DMF (4) (Am-H2ip = 5-aminoisophthalic acid, H2ip = isophthalic acid, OH-H2ip = 5-hydroxyisophthalic acid, and H2sdba = 4,4'-sulfonyldibenzoic acid), have been prepared by solvothermal reactions of Mn(II) ions with different polycarboxylate acids in the presence of LiNO3 or NH4NO3. Single-crystal X-ray diffraction studies reveal that the frameworks of 1-4 contain diverse Mn(II)-oxygen inorganic magnetic chain's sequences, -J1J1J1J1- for 1, -J1J2J1J2- for 2, -J1J1J2J2- for 3, and -J1J2J3J3- for 4. The sequence in 4 has never been seen for the magnetic chain compounds and is a new type of magnetic alternating sequence. Magnetic investigations indicate that these compounds all show weak antiferromagnetic couplings between the adjacent Mn(II) ions. Magnetostructural analyses based on the data of 1-4 and other related Mn(II) chain compounds imply that the magnitude of the magnetic coupling has some relationship with the Mn-O-Mn angle of the µ2-O bridge and the average Mn-O-C-O torsion angle of the carboxylate bridges. Compounds 2 and 4 crystallize in chiral and acentric space groups, and they both exhibit powder second harmonic generation (SHG) efficiencies approximately 0.6 and 0.9 times, respectively, that of the standard potassium dihydrogen phosphate (KDP) powder. In addition, the dielectric properties of 2 and 4 were also investigated.

Boosting the oxygen reduction activity of non-metallic catalysts via geometric and electronic engineering through nitrogen and chlorine dual-doping.

The development of heteroatom dual-doped porous carbon frameworks with uniform doping is highly desirable for achieving highly efficient oxygen reduction reaction (ORR) activity, due to their tunable chemical and electronic structures. Herein, porous covalent triazine-based frameworks (CTFs) incorporating nitrogen/chorine dual-doped porous carbon networks were fabricated by selecting 1,3-bis(4-cyanophenyl) imidazolium chloride as a building block, in a facile and controllable way via a bottom-up strategy. The resulting nitrogen/chorine dual-doped catalyst CCTF-700 exhibits excellent ORR performance with a more positive onset and half-wave potential (0.85 V vs. RHE), higher diffusion-limited current density and significantly improved stability in comparison with the benchmark commercial 20 wt% Pt/C catalyst. It is worth mentioning that CCTF-700 shows one of the best ORR performances among all the reported metal-free electrocatalysts under alkaline conditions. This work paves the way for a controllable and reliable strategy to craft highly efficient heteroatom dual-doped carbon catalysts for energy conversion.

A novel series of giant cobalt-calixarene macrocycles: ring-expansion and modulation of pore apertures through recrystallization.

The design and synthesis of metallomacrocycles can be quite challenging because the assemblies of such molecular cycles are difficult to control and the products are usually unpredictable. In this work, a novel series of metallomacrocycles, denoted as {Co30-A}, {Co30-B} and {Co32-A} have been synthesized via self-assembly of p-tert-butylthiacalix[4]arene (H4TC4A) and 3,5-pyrazoledicarboxylic acid (H3pdc) with Co2+ ions under solvothermal conditions. Recrystallization of {Co32-A} under different conditions was found to form {Co32-B} and {Co32-C} that have a similar ring structure to that of {Co32-A} but have different molecular packing modes in the lattices, as well as a 40-membered ring {Co40}. These complexes represent the highest-nuclearity metallocalixarene coordination wheels reported to date. Crystallographic studies indicate that all these metallomacrocycles feature wheel-like structures with apertures varing from 11.4 to 20.3 Å. It is noteworthy that {Co32-A} exhibited good efficiency in removing RhB even at low initial concentration (10 ppm) and also excellent adsorption selectivity towards RhB over Na2Fl (RhB = Rhodamine B, Na2Fl = disodium fluorescein). This work not only makes a breakthrough in the synthesis of metallocalixarene macrocycles with high nuclearity and large apertures, but also provides a simple recrystallization approach to realize the ring-expansion and regulation of molecular packing modes of the metallomacrocycles.

Facile and scalable synthesis of Ti6Mn2 oxo-cluster nanocrystals with flower-like morphology and excellent photocatalytic properties.

Three new phenylphosphonate (PhPO3) and salicylate (Sal) substituted heterometallic titanium-oxo clusters (ST-M), namely [Ti6Mn2O4(OEt)4(PhPO3)2(Sal)6(EtOH)2] (ST-Mn), [Ti6Zn2O4(OEt)4(PhPO3)2(Sal)6(EtOH)2(H2O)2] (ST-Zn) and [Ti6Tb2O4(OiPr)4(PhPO3)2(Sal)6Cl2(iPrOH)2]·iPrOH (ST-Tb), were synthesized. The most impressive structural feature of these compounds is the calixarene-type carboxylate endpoint in the Ti6-oxo core, which can readily capture metal ions with different radii and coordination geometries, for example, Mn2+, Zn2+ and Tb3+ ions in this case, to generate neutral mixed-metal Ti6M2-oxo clusters. Flower-like ST-Mn (denoted as FST-Mn) nanocrystals formed by nanosheets can be facilely obtained in gram-scale quantities from a simple solution reaction using Triton X-100 as a conditioning agent. The catalytic activity of these materials was evaluated by photocatalytic degradation of rhodamine B (RhB), among which FST-Mn showed the highest catalytic activity. Under visible light, 93.0% of RhB (50 ppm, 100 mL) was decomposed within 30 min catalyzed by FST-Mn without adding hydrogen peroxide, which is quite preeminent among Ti based catalysts. The catalytic decomposition efficiency under the same experimental conditions was 80.0% for ST-Mn, 24.6% for ST-Zn and 17.6% for ST-Tb. Investigation of the degradation mechanism showed that h+ and ·OH were the dominant active species in the decomposition of RhB. Moreover, the reusability and stability of FST-Mn were also verified.

A stable LnMOF as a highly efficient and selective luminescent sensor for detecting malachite green in water and real samples.

A series of isostructural 3D lanthanide metal-organic frameworks (LnMOFs), with the formula n(H3O)[Ln(L)(H2O)] n ·nH2O (Ln = Gd 1, Eu 2 and Tb 3, H4L = 3,5,3',5'-oxytetrabenzoic acid), have been successfully synthesized by solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that 1-3 are constructed from wave-like Ln-carboxylate chains which are further connected by the ligands to form 3D channel-type frameworks. Further experiments suggest that 3 is thermally stable up to 322 °C and exhibits outstanding chemical stability in aqueous solutions with the pH ranging from 3 to 11. Significantly, 3 can be utilized for the first time to detect malachite green (a synthetic antibiotic to cure saprolegniasis) in aqueous media even in the presence of other interfering antibiotics, with a high sensitivity (K sv = 8.33 × 104 M-1), low detection limit (DL = 0.25 µM) and good recyclability. On a more practical note, we found that the luminescence intensity of 3 showed almost no response to pH changes (pH 3-11), allowing steady sensing in real samples such as river water, simulated human serum and urine with satisfactory recoveries and RSD.

Continuous band-gap reduction on ZnO submicrorods via covering with ZnS(1-x)Se(x) or ZnSe(1-x)Te(x) alloy in core/sheath morphology.

Submicrosized alloy cables of ZnO/w-ZnS(1-x)Se(x) (0 < x < 1) and ZnO/s-ZnSe(1-x)Te(x) (0.8 < or = x < 1) have been prepared. The lattice parameters of the sheath show linear compositional dependence following Vegard's law. The composition-band gap dependence follows the trend of E(g)(ZnO/w-ZnS(1-x)Se(x))(x) = 3.60 - 1.77x + 0.87x(2) (0.22 < or = x < or = 1), E(g)(ZnO/w-ZnS(1-x)Se(x)) = 3.25 eV (0 < or = x < or = 0.22), and E(g)(ZnO/s-ZnSe(1-x)Te(x))(x) = 2.65 - 1.82x + 1.41x(2) (0 < or = x < or = 1), respectively. The continuous band-gap modulations on ZnO-based heterostructures are associated with the core/sheath morphology and the nature of the sheath alloys.

[Multi-spectroscopy applied to study blue gel pen inks].

Multi-spectroscopy, such as FTIR, dispersive Raman spectroscopy and UV-Vis, was applied to characterize the blue gel pen inks on paper at the time in the present study. Twenty eight collected blue gel pens with different brands and serials were separated into four different classes by different absorptions or Raman shift. Composition changing of blue gel pen inks on paper during artificial ageing was studied via TD-MS as well. The advantage and disadvantage of this spectroscopy used in analyzing and identifying blue gel pen inks on paper, and the potential application in the research on relative and absolute ageing of documents were discussed.

The antimony-based type I clathrate compounds Cs(8)Cd(18)Sb(28) and Cs(8)Zn(18)Sb(28).

In phase: The title compounds lie in a new region of phase space for such a structure, and have stoichiometries in accord with a classical Zintl phase formulation. The small semiconductor gaps indicated by DFT calculations are also supported by their diamagnetic susceptibilities.

A new approach to fabricate the Mn(ii)-based magnetic refrigerant through incorporation of a diamagnetic {LiO4} spacer.

A new 3D MOF [MnLi2(ip)2(H2O)2] (1) with a 1D heterometallic inorganic Mn(ii)-Li(i) chain is reported. With the assistance of diamagnetic {LiO4} connectors, which separate the paramagnetic Mn(ii) ions and act as magnetic spacers, very weak magnetic interactions were obtained. Remarkably, 1 showed a significant magnetocaloric effect (MCE) with a large entropy change value of 30.4 J kg-1 K-1 for ΔH = 8 T at 2 K.

A novel alb metalloring organic framework with a {Ni12Gd24} cage exhibiting a significant magnetocaloric effect.

With the aid of a bifunctional 6-mercaptonicotinic acid ligand, a novel {Ni12Gd24} cage-based (6, 12)-c alb-MROF that is assembled from a {Gd4(OH)4(COO)6} trigonal-prism building unit and a {Ni6S12} hexagonal-prism molecular building block has been synthesized for the first time. It exhibits a large MCE value of 29.86 J kg-1 K-1 for ΔH = 8 T at 2 K.

Microporous Lanthanide Metal-Organic Frameworks with Multiple 1D Channels: Tunable Colors, White-Light Emission, and Luminescent Sensing for Iron(II) and Iron(III).

A new series of isostructural lanthanide-based metal-organic frameworks, [H3 O][HN(CH3 )3 ]2 [Ln3 L6 ] (Ln=Gd (1), Eu (2), and Tb (3); H2 L=1,3-benzenedicarboxylic acid), was prepared under solvothermal conditions. Single-crystal XRD studies reveal that these compounds are 3D microporous frameworks with 1D channels distributed in four different directions. The 1D channels contain protonated water molecules and trimethylammonium cations, which can be partially exchanged with different metal ions. Notably, these compounds do not contain any coordinated solvent molecules because the coordination sphere of the Ln3+ ion is fully occupied by chelating and bridging carboxylate oxygen atoms. Tunable colors and white-light emission can be achieved by encapsulating different molar ratios of Eu3+ and Tb3+ ions in the Gd framework through cation exchange. In addition, the Eu framework can act as a sensitive and selective luminescence sensor for both Fe2+ and Fe3+ .

Chiral template induced homochiral MOFs built from achiral components: SHG enhancement and enantioselective sensing of chiral alkamines by ion-exchange.

A pair of chiral template induced anionic homochiral frameworks constructed from achiral components has been synthesized. Ion-exchange of counter cations with polar or chiral organic cations enhances the SHG efficiency of the frameworks. The enantioselective sensing of chiral alkamines can be achieved by the SHG response.

An unusual chiral 3D inorganic connectivity featuring a {Pb18} wheel: rapid and highly selective and sensitive sensing of Co(II).

A pair of enantiomorphic frameworks featuring rare chiral 3D inorganic connectivity and a {Pb18} wheel, has been obtained via spontaneous resolution. They exhibit rapid and highly selective and sensitive sensing of Co(2+) ions.

Reversible crystal-to-amorphous-to-crystal phase transition and a large magnetocaloric effect in a spongelike metal organic framework material.

Reversible crystal-to-amorphous-to-crystal phase transition accompanied by changes in magnetic and NLO properties was first observed in a rigid non-porous spongelike MOF material. The crystal phase exhibits a high magnetocaloric effect, while the amorphous phase has potential application as a magnetic DMF sensor.

Synthesis, structure and magnetic study of a novel mixed-valent Co(II)10Co(III)4 shield constructed by mixed pyridine-alcoholate ligands.

A novel tetradecanuclear mixed-valent cobalt cluster, formulated as [Co(II)(10)Co(III)(4)(OH)(2)O(6)(hmp)(10)(pdm)(4)(CH(3)OH)(2)]·5H(2)O (1), was obtained using mixed ligands of 2-(hydroxymethyl)pyridine (hmpH) and 2,6-pyridinedimethanol (pdmH(2)). The cobalt ions in 1 are connected by ten chelating hmp(-) ligands, four tris-chelating pdm(2-) ligands and six µ(3)-oxide/hydroxide anions, forming a unique shield-like planar structure that is rarely observed for Co-based clusters. Compound 1 displays slight frequency dependence at static zero field below 4.5 K, suggesting that it might be a single molecule magnet (SMM).

Syntheses, topological analyses, and NLO-active properties of new Cd(II)/M(II) (M = Ca, Sr) metal-organic frameworks based on R-isophthalic acids (R = H, OH, and t-Bu).

Solvothermal syntheses of Cd(NO(3))(2)·4H(2)O and R-isophthalic acids (R = H, OH and t-Bu) in the presence of Ca(II) or Sr(II) lead to four new three-dimensional Cd(II)/Ca(II) or Cd(II)/Sr(II) heterometallic frameworks: [CdCa(m-BDC)(2)(DMF)(2)] (1), [CdSr(2)(m-BDC)(2)(NO(3))(2)(DMF)(4)] (2), [CdCa(OH-m-BDC)(2)(H(2)O)(2)]·2Me(2)NH (3), and (Me(2)NH(2))(2)[Cd(2)Ca(Bu(t)-m-BDC)(4)] (4) (m-H(2)BDC = isophthalate, OH-m-H(2)BDC = 5-hydroxyisophthalate and Bu(t)-m-H(2)BDC = 5-butylisophthalate). All of these compounds except for 4 crystallize in acentric (or chiral) space groups and the bulk materials for 1 and 3 display strong powder SHG efficiencies, approximately 1.54 and 2.31 times than that of a potassium dihydrogen phosphate (KDP) powder. Topological analyses show that 1 and 2 have structures with sxb and dia topologies, respectively, while both 3 and 4 exhibit pcu topological nets when the metal carboxylate clusters are viewed as nodes. The fluorescence properties and thermal stabilities for these compounds are also investigated.

catena-Poly[[[mu-1,4-bis(imidazol-1-ylmethyl)benzene-kappa2N3:N3']bis[dichlorocopper(II)]]-bis[mu-1,4-bis(imidazol-1-ylmethyl)benzene]-1:1'kappa2N3:N3';2:2'kappa2N3:N3'].

The title compound, [Cu2Cl4(bix)3]n [bix is 1,4-bis(imidazol-1-ylmethyl)benzene, C14H14N4], has been synthesized by the hydrothermal method. The copper(II) center has a five-coordinate trigonal-bipyramidal geometry. Each bix ligand binds with two CuII ions, forming ladder-like structures which are connected by pi-pi stacking interactions to form a two-dimensional network.