A triphenylamine-based carbohydrazide hydrazone fluorescent probe for selective detection of hypochlorite and sensing acidic gases.

Hypochlorous acid and its hypochlorite are important reactive oxygen species in the body, and are involved in various physiological processes related to immunity; their rapid detection is of great significance. Here, we synthesized a fluorescent probe (TPAS) by condensation of 4-(diphenylamino)benzaldehyde, carbohydrazide, and salicylaldehyde, which can be used for the detection of ClO- in water and sensing of acidic gas in its solid state. The probe showed strong selective recognition of ClO- in acetonitrile and good tolerance to interference ions. There were good linear responses between the intensity of absorbance and fluorescence and the amount of ClO-. The TPAS solid and its paper strips can emit red fluorescence when exposed to volatile acidic vapours. After being treated with NH3, the red fluorescence can be restored to yellow. The response process of TPAS to ClO- and acid gases was characterized using nuclear magnetic resonance, electrospray ionisation mass spectrometry, transmission electron microscopy, and density functional theory calculations. Furthermore, it can be utilized in analyzing ClO- in commercially available bleaching products; the detection results were basically compatible with the labelled values. In addition, the probe is biocompatible and can be applied for imaging ClO- in zebrafish.

Exploring the Performance Improvement for CO2 Chemical Fixation in Zn/ZnMg-MOFs.

A new 3D zinc-based metal-organic framework {[Zn7L2(DMF)3(H2O)(OH)2]·5DMF}n (1) (H6L = 5,5',5″-(methylsilanetriyl) triisophthalic acid) was constructed with an organosilicon-based linker, where H6L is a tetrahedral structure furnished with rich -COO- chelating sites for Zn(II) immobilization. Compound 1 exhibited two types of irregular one-dimensional channels and a three-dimensional skeleton with large specific surface area, making it a promising catalytic platform. Moreover, by incorporation of the second metal ion into the inorganic node of framework 1, isomorphic bimetallic MOF ZnMg-1 was successfully synthesized. ZnMg-1 demonstrated enhanced catalytic activity compared to 1 under identical conditions. Contrast experiments and theoretical calculations indicate that bimetallic active sites play a facilitating role in the chemical fixation of epoxides and CO2. It indicated that efficient chemical fixation of CO2 to cyclic carbonates was obtained over isomorphic MOF catalysts 1 and ZnMg-1.

Sulfonate substituted rhodamine hydrophilic fluorescent probes: Application to specific detection of Fe3+ and imaging in living fish.

Two Sulfonate substituted rhodamine hydrophilic fluorescent probes RbS1 and RbS2 were designed and synthesized for specific detection of Fe3+. It was found that the probe RbS2 was stronger than RbS1 in the water solubility test. Both of them displayed responses to Fe3+ with a apparent fluorescence enhancement at 585 nm, accompanied with a distinct fluorescence change to pink. Upon addition of Fe3+ ions (0-16 µM), the emission intensity of RbS1 and RbS2 increased to 40 and 70 fold, which exhibited a good linear relationship with the concentration of Fe3+. The detection limits of RbS1 and RbS2 for sensing Fe3+ were 0.64 µM and 0.56 µM, respectively. The binding ratios of the RbS1 and RbS2 to Fe3+ were 1:1 and the recycling ability for Fe3+ was reasonable. RbS1 and RbS2 have been successfully applied to the determination of Fe3+ in real water samples with satisfactory recovery and accuracy. In further living fish imaging test, the probe RbS2 was distributed into abdomen, which exhibited better fluorescence imaging ability than that of RbS1.

A NiII-cluster-based MOF as an efficient heterogeneous catalyst for the chemical transformation of CO2.

A novel 3D metal-organic framework based on Ni4 clusters as nodes has been synthesized using a tetrahedral linker of 5,5',5''-(methylsilanetriyl)triisophthalic acid (H6L). The compound possesses 1D channels with potential pore volumes that can accommodate guest molecules. Investigations on the coupling reaction of epoxides and CO2 indicate that the compound can be used as an efficient catalyst for CO2 chemical fixation, and its catalytic performance is greatly superior to most MOF-based catalysts. Additionally, compound 1 can be recycled at least five times without compromising its activity.

Correction: A microporous Cu-MOF with optimized open metal sites and pore spaces for high gas storage and active chemical fixation of CO2.

Correction for 'A microporous Cu-MOF with optimized open metal sites and pore spaces for high gas storage and active chemical fixation of CO2' by Chao-Ying Gao et al., Chem. Commun., 2016, 52, 11147-11150.

Porous Anionic Uranyl-Organic Networks for Highly Efficient Cs+ Adsorption and Investigation of the Mechanism.

Exploitation of new materials for the removal of long-lived and highly radioactive actinides and their fission products produced in the nuclear fuel cycle is crucial for radionuclide management. Here, two rare porous anionic uranyl-organic frameworks (UOFs) have been successfully synthesized by a judicious combination of the tetratopic carboxylate ligand 1,3,6,8-tetrakis( p-benzoic acid)pyrene (H4TBAPy) and D3 h-symmetrical triangular [UO2(COO)3]-. The resulting two compounds exhibit different architectures, albeit with similar coordination modes. Of interest is that they have excellent adsorption performance on Cs+ from aqueous solution. The high removal efficency would make them promising in applications of radioactive waste management. Notably, the framework of compound 2, [(CH3)2NH2]4[(UO2)4(TBAPy)3]·22DMF·37H2O is sufficiently robust to allow the accessibility of intriguing single crystals of a Cs+-adsorbed derivative, which helps to elucidate the adsorption mechanism. The structural, bonding, and spectroscopic properties of the above compounds are examined using relativistic density functional theory (DFT). It is found that the adsorption toward cesium on UOFs is energetically favored, which features largely ionic bonds and is dominated by electrostatic attraction.

A highly stable MnII phosphonate as a highly efficient catalyst for CO2 fixation under ambient conditions.

With coordinatively unsaturated metal centers decorating the channel walls, a MnII phosphonate exhibits highly efficient and substrate size-selective catalysis in the context of CO2 chemical conversion into cyclic carbonates under 1 atm pressure and at room temperature, proving to be a promising heterogeneous catalyst in an eco-friendly and energy efficient way.

A copper-phosphonate network as a high-performance heterogeneous catalyst for the CO2 cycloaddition reactions and alcoholysis of epoxides.

A novel 3D copper-phosphonate network, with the general formula Cu7(H1L)2(TPT)3(H2O)6, namely compound 1, has been synthesized using a rigid tetrahedral linker tetraphenylsilane tetrakis-4-phosphonic acid (H8L) and a nitrogen-containing ancillary ligand (TPT: [5-(4-(1H-1,2,4-triazol-1-yl)phenyl)-1H-tetrazole]) under hydrothermal conditions. The compound was fully characterized using PXRD, ICP, IR, TGA and elemental analysis. Compound 1 can be used as an efficient catalyst for the CO2 coupling reaction that is greatly superior to many conventional MOF-based catalysts, where porosity is always mentioned and used. In addition, it shows excellent catalytic performance for ring-opening reactions with epoxides under ambient conditions. Additionally, compound 1 can be recycled at least three times without a significant compromise in the activity in the two catalytic reactions.

Fe3O4@ZIF-8: a magnetic nanocomposite for highly efficient UO22+ adsorption and selective UO22+/Ln3+ separation.

The magnetic nanocomposite Fe3O4@ZIF-8 was for the first time used as an excellent adsorbent for the fast adsorption and separation of UO22+ ions from aqueous solutions. This material exhibited an unprecedented adsorption capacity of 523.5 mg U per g and a remarkable selectivity towards UO22+/Ln3+ at pH = 3.

An ultrastable zirconium-phosphonate framework as bifunctional catalyst for highly active CO2 chemical transformation.

A zirconium-phosphonate network, as a bifunctional catalyst for carbon dioxide (CO2)/epoxide coupling reaction, exhibits very high activity that is superior to most documented metal-organic framework (MOF)-based catalysts. Furthermore, it possesses extraordinary tolerance to extremely harsh conditions, such as aqua regia. This paper describes the use of metal phosphonate as a new MOF applied to CO2 transformation.

A microporous Cu-MOF with optimized open metal sites and pore spaces for high gas storage and active chemical fixation of CO2.

A microporous Cu-MOF with optimized open metal sites and pore space was constructed based on a designed bent ligand; it exhibits high-capacity multiple gas storage under atmospheric pressure and efficient catalytic activity for chemical fixation of CO2 under mild conditions.

A Multifunctional Mn(II) Phosphonate for Rapid Separation of Methyl Orange and Electron-Transfer Photochromism.

A Mn(II) phosphonate of the general formula [Mn(H2 L)2 (H2 O)2 (H2 bibp)] adopts a layered motif with protonated H2 bibp(2+) cations embedded in the channels (H4 L=thiophene-2-phosphonic acid; bibp=4,4'-bis(1-imidazolyl)biphenyl). The title compound exhibits excellent adsorptive removal of methyl orange (MO) dye from aqueous solution. Its advantageous features include fast adsorption, high uptake capacity, selective removal, and reusability, which are of great significance for practical application in wastewater treatment. Meanwhile, the compound displays rapid photochromism upon irradiation with visible light at room temperature. Extensive research has demonstrated that such behavior is based on a ligand-to-ligand charge-transfer (LLCT) mechanism. The irradiated sample possesses an ultra-long-lived charge-separated state. Moreover, not only is the compound the first Mn-based photochromic MOF, but it is also one of the very few examples showing LLCT with non-photochromic components.

Entangled Uranyl Organic Frameworks with (10,3)-b Topology and Polythreading Network: Structure, Luminescence, and Computational Investigation.

Two 3D uranyl organic frameworks (UOFs) with entangled structures, (HPhen)2[(UO2)2L2]·4.5H2O (1) and [(UO2)3(H2O)4L2]·6H2O (2), were synthesized using a rigid tripodal linker (4,4',4″-(phenylsilanetriyl)tribenzoic acid, H3L). Compound 1 represents a 2-fold interpenetrating UOF with the unique (10,3)-b topology. Compound 2 is composed of three interlocked sets of identical singlet networks and thus exhibits a rare 3D polythreading network with (3,4)-connected topology. These two compounds have been characterized by IR, UV-vis, and photoluminescent spectroscopy. A density functional theory (DFT) study on the model compounds of 1 and 2 shows good agreement of structural parameters and U═O stretching vibrational frequencies with experimental data. The experimentally measured absorption bands were well reproduced by the time-dependent DFT calculations.

Particular Handedness Excess through Symmetry-Breaking Crystallization of a 3D Cobalt Phosphonate.

A 3D chiral cobalt phosphonate has been obtained from achiral precursors in the absence of chiral inducers. Remarkably, the bulk sample is largely enantio-enriched with particular handedness through symmetry-breaking crystallization in spite of multiple repeated experiments. Moreover, protonation of this chiral material introduces Brønsted acid sites, the structure of which is unique to the heterogeneous phase for the ring opening of epoxies.