A New Porphyrin-based Covalent Organic Framework with High Iodine Capture Capacity and I-doping Enhanced Conductivity.

Covalent organic frameworks (COFs) are porous organic materials with well-defined and uniform structure. The material is an excellent candidate as a solid adsorbent for iodine adsorption. In the present study, we report the synthesis of COF with porphyrin moiety, TF-TA-COF, by solvothermal reaction, which was characterized by XRD, solid-state 13 C NMR, IR, TGA, and nitrogen adsorption-desorption analysis. TF-TA-COF showed a high specific surface area of 443 m2 g-1 , and exhibited good adsorption performance for iodine vapor, with an adsorption capacity of 2.74 g g-1 . XPS and Raman spectrum indicated that a hybrid of physisorption and chemisorption took place between host COF and iodine molecules. The electric properties of iodine-loaded TF-TA-COF were also studied. After doped with iodine, the conductivity of the material increased by more than 5 orders of magnitude. The photoconductivity of I2 -doped COF was also studied and TF-TA-COF showed doping-enhanced photocurrent generation.

catena-Poly[[(5-phenyl-2,2'-bipyridine-κN,N')copper(I)]-µ-thio-cyanido-κN:S].

The title compound, [Cu(NCS)(C(16)H(12)N(2))](n), was synthesised under hydro-thermal conditions. The Cu(I) ion shows distorted tetra-hedral geometry being coordinated by two N atoms from a 5-phenyl-2,2'-bipyridine ligand and by the N and S atoms from two different thio-cyanate anions. The Cu(I) ions are bridged by thio-cyanide groups, forming a one-dimensional coordination polymer along the b axis. The crystal packing is through van der Waals contacts and C-H⋯π inter-actions.

Metal-organic framework bearing new viologen ligand for ammonia and Cr2O7 2- sensing.

Three anionic metal-organic frameworks (MOFs) {[Zn3(BTEC)2(H2O)(4-BCBPY)]·(H2O)} n (1-3) (BTEC4- = 1,2,4,5-benzenetetracarboxylic acid anion, 4-BCBPY2+ = 1,1'-bis(4-cyanobenzyl)-4,4'-bipyridinium dication) were synthesized in the reaction of 1,2,4,5-benzenetetracarboxylic acid with different metal salts such as ZnNO3, ZnCl2, and ZnSO4, under solvothermal conditions in the presence of 1,1'-bis(4-cyanobenzyl)-4,4'-bipyridinium chloride. Single crystal X-ray diffraction analysis shows that compounds 1, 2 and 3 have MOF structures based on binuclear metal building units, which are connected by two protonated BTEC4- ligands and three zinc ions, and the viologen cation 4-BCBPY2+ is located in the channel to achieve charge balance. Compounds 1, 2 and 3 have good photosensitivity, respond to sunlight, UV light and blue ray, and turn blue. The D-A distance and π-π stacking distance of the discolored samples (1P, 2P and 3P) changed. In addition, the three compounds showed visible color changes to ammonia vapor, rapidly changing from white to blue. At the same time, the three compounds exhibited fluorescence quenching to ammonia vapor and Cr2O7 2-. It is further proved that compounds 1, 2 and 3 are fluorescent sensors with a low detection limit (for Cr2O7 2-: 10-5 M) and high sensitivity for ammonia vapor and Cr2O7 2-. It was found that photochromic behavior, ammonia sensing properties can be tuned by the nature of metal salts.

Poly[penta-kis-(µ-cyanido-κN:C)tris-(5-phenyl-2,2'-bipyridine-κN,N')penta-copper(I)].

The hydro-thermal reaction of Cu(acetate)(2) and K(3)[Fe(CN)(6)] with 5-phenyl-2,2'-bipyridine (5-ph-2,2'-bpy) in water yields the polymeric title complex, [Cu(5)(CN)(5)(C(16)H(12)N(2))(3)](n), which consists of ribbons along the a axis, constructed from 26-membered {Cu(10)(CN)(8)} rings. In these rings, the metal atoms are bridged by cyanide groups, except for one close Cu⋯Cu contact [2.7535 (12) Å], which can be considered as ligand-unsupported. Within the rings, one Cu atom has a distorted tetra-hedral geometry through the coordination to two N atoms from 5-ph-2,2'-bpy and two N/C atoms from two cyanide groups. Two Cu atoms have a trigonal planar environment being coordinated by three cyanide groups and two other Cu atoms have a distorted square planar geometry through coordination to two N atoms from 5-ph-2,2'-bpy and two N/C atoms from two cyanide groups.

Photocatalytic Degradation of Deoxynivalenol Using Cerium Doped Titanium Dioxide under Ultraviolet Light Irradiation.

Deoxynivalenol (DON) is a major mycotoxin with high toxicity that often contaminates grains, foods and feeds. The traditional approaches for DON removal are difficult to meet industry and agriculture demands due to the high stability of the DON molecule. Therefore, there is an urgent need to develop green and effective strategies for DON degradation. In this study, a batch of photocatalytic nanomaterials of cerium (Ce) doped titanium dioxide (TiO2) were successfully prepared by sol-gel method. The catalysts were systematically characterized by XRD, HRTEM, FT-IR, UV-Vis and XPS. The catalyst 0.5Ce-TiO2 showed superior photocatalytic activity for DON degradation in aqueous solution under ultraviolet light irradiation, better than that of traditional photocatalyst pure TiO2, and 96% DON with initial concentration of 5.0 mg/L could be degraded in 4 h. In addition, the two possible degradation intermediate products C5H8O3 and C17H18O6 were identified, the photocatalytic degradation mechanism and degradation pathway were studied. The results indicate that Ce doped TiO2 photocatalyst can be used to reduce DON effectively.

Metal-dependent assembly of a helical-[Co3L3] cluster versus a meso-[Cu2L2] cluster with O,N,N',O'-Schiff base ligand: structures and magnetic properties.

Self-assembly of a tetradentate ligand, N, N'-bi(salicylidene)-2,6-pyridinediamine (H 2L), with Cu(II) or Co(II), affords a dinuclear [Cu 2L 2] complex ( 1) or a trinuclear [Co 3L 3] complex ( 2), which were characterized by the single crystal X-ray diffraction study. The coordination geometry of the Cu (II) centers in 1 is between square planar and tetrahedral, with the ligand adopting a cis-cis conformation to give a centrally symmetric structure, which can be regarded as a mesocate. However, the coordination geometry of Co (II) centers in 2 is distortedly tetrahedral, and the ligand adopts a cis-trans conformation. The whole complex of 2 is of a pseudo- C 3 symmatrical, torus-like structure, which can be regarded as a circular helicate. Both the mesocate and the helicate exhibit expanded supramolecular structures due to elaborate intercomplex pi-stacking interactions. These two complexes were also characterized by element analysis, IR spectra, and TGA. To verify the stability of 2, ESI-MS was carried out on both the crystal and the powdered samples. Variable temperature magnetic susceptibility measurements reveal that both 1 and 2 display antiferromagnetic properties. DFT calculations were carried out on 1 to verify the antiferromagnetic coupling between intracluster metal centers.

Crystal structure of poly[(2,2'-bi-pyridine-κ(2) N,N')tetra-kis-(µ-cyanido-κ(2) N:C)dinickel(II)].

The polymeric title complex, [Ni2(CN)4(C10H8N2)] n , was obtained serendipitously under hydro-thermal conditions. The asymmetric unit consists of one half of an [Ni(CN)4](2-) anion with the Ni(2+) cation situated on an inversion centre, and one half of an [Ni(2,2'-bpy)](2+) cation (2,2'-bpy is 2,2'-bi-pyridine), with the second Ni(2+) cation situated on a twofold rotation axis. The two Ni(2+) cations exhibit different coordination spheres. Whereas the coordination of the metal in the anion is that of a slightly distorted square defined by four C-bound cyanide ligands, the coordination in the cation is that of a distorted octa-hedron defined by four N-bound cyanide ligands and two N atoms from the chelating 2,2'-bpy ligand. The two different Ni(2+) cations are alternately bridged by the cyanide ligands, resulting in a two-dimensional structure extending parallel to (010). Within the sheets, π-π inter-actions between pyridine rings of neighbouring 2,2'-bpy ligands, with a centroid-to-centroid distance of 3.687 (3) Å, are present. The crystal packing is dominated by van der Waals forces. A weak C-H⋯N inter-action between adjacent sheets is also observed.