A Naphthalenediimide-Based Metal-Organic Framework and Thin Film Exhibiting Photochromic and Electrochromic Properties.

A multifunctional metal-organic framework, NBU-3, has been explored as a 2D three-connected network based on a naphthalenediimide-based ligand. The NBU-3 crystals display photochromic properties, and NBU-3 thin films on FTO substrates exhibit electrochromic properties. NBU-3 is the first example of MOF materials containing both photochromic and electrochromic properties, which can be desirable for thin film devices.

Doubly interpenetrated chiral (10,3)-a network with charge-transfer-type guest inclusion.

A doubly interpenetrated metal-organic framework, [Zn(3)(TATB)(2)(H(2)O)(2)](n) (2), with chiral (10,3)-a topology, has been synthesized from an achiral, trigonal-planar ligand, 4,4',4″-s-triazine-2,4,6-triyltribenzoate (TATB). The large chiral channels in 2 act as scaffolds for the inclusion of N,N-dimethylaniline (DMA) molecules by donor-acceptor interactions. The resulting host-guest composite, DMA@2, shows desirably intense luminescence, which originated from photoinduced charge-transfer interactions in excited states.

A chiral interdigitated supramolecular network assembled from single-stranded helical tubes.

The amino-functionalized helical chiral one-dimensional coordination polymer catena-poly[[bis(pyridine-κN)zinc(II)]-µ-2-aminobenzene-1,4-dicarboxylato-κ(4)O(1),O(1'):O(4),O(4')], [Zn(C(8)H(5)NO(4))(C(5)H(5)N)(2)](n), has an extended structure that is assembled from 2-aminobenzene-1,4-dicarboxylate anions and Zn(2+) cations and which presents a left-handed 4(3) helix with a pitch of 25.6975 (9) Å. All the pyridine rings and all the amino groups point away from the helix to generate a hollow tube with a cross-section of approximately 8 × 8 Å running parallel to the crystallographic c direction. Each single-stranded helix is interdigitated with four neighbouring helices via N-H···O hydrogen bonds, which gives rise to a dense homochiral three-dimensional supramolecular network.

Bis(dimethyl-ammonium) 2,2'-(1,3,6,8-tetra-oxo-2,7-diaza-pyrene-2,7-di-yl)diacetate.

The asymmetric unit of title compound, 2C(2)H(8)N(+)·C(18)H(8)N(2)O(8) (2-), comprises one crystallographically independent dimethyl-ammonium cation and half of a 2,2'-(1,3,6,8-tetra-oxo-2,7-diaza-pyrene-2,7-di-yl)diacetate dianion. The anion lies on an inversion centre and the two carboxyl-ate groups are in trans positions based on the naphthaleneteracarb-oxy-lic diimide group. The crystal packing is stabilized by N-H⋯O hydrogen bonds between cations and anions, as well as by π-π inter-actions between the naph-thaleneteracarb-oxy-lic diimide groups [centroid-centroid distance = 4.812 (3) Å].

Ab initio calculations on halogen-bonded complexes and comparison with density functional methods.

A systematic theoretical investigation on a series of dimeric complexes formed between some halocarbon molecules and electron donors has been carried out by employing both ab initio and density functional methods. Full geometry optimizations are performed at the Moller-Plesset second-order perturbation (MP2) level of theory with the Dunning's correlation-consistent basis set, aug-cc-pVDZ. Binding energies are extrapolated to the complete basis set (CBS) limit by means of two most commonly used extrapolation methods and the aug-cc-pVXZ (X = D, T, Q) basis sets series. The coupled cluster with single, double, and noniterative triple excitations [CCSD(T)] correction term, determined as a difference between CCSD(T) and MP2 binding energies, is estimated with the aug-cc-pVDZ basis set. In general, the inclusion of higher-order electron correlation effects leads to a repulsive correction with respect to those predicted at the MP2 level. The calculations described herein have shown that the CCSD(T) CBS limits yield binding energies with a range of -0.89 to -4.38 kcal/mol for the halogen-bonded complexes under study. The performance of several density functional theory (DFT) methods has been evaluated comparing the results with those obtained from MP2 and CCSD(T). It is shown that PBEKCIS, B97-1, and MPWLYP functionals provide accuracies close to the computationally very expensive ab initio methods.

A novel (3,4,10)-connected three-dimensional hydrogen-bonded supramolecular network containing a cyclic water hexamer.

The title compound, 4,4'-(1,1,1,3,3,3-hexafluoroisopropylidene)diphthalic acid hexahydrate, C(19)H(10)F(6)O(8).6H(2)O, crystallizes in the centrosymmetric space group Pbcn, with half of the diphthalic acid residue and three water molecules in the asymmetric unit. The organic molecule is located on a crystallographic twofold axis. In the solid, cyclic water hexamers in chair conformations have crystallographically imposed inversion symmetry. Strong O-H...O hydrogen bonds between the hexamers and organic molecules result in a unique three-dimensional supramolecular network [O...O = 2.554 (2)-2.913 (2) A]. This compound represents the first example of a (3,4,4,10)-connected four-nodal supramolecular topology with the Schläfli symbol (4(3).5.6.7)(2)(4(3).5(2).7)(2)(4(3))(2)(4(6).5(6).6(2).7(8).8(14).9(9)).

Bis(benzoyl-acetonato)bis-(1,3-di-4-pyridyl-propane)manganese(II).

In the title compound, [Mn(C(10)H(9)O(2))(2)(C(13)H(14)N(2))(2)], the Mn(II) ion lies on a crystallographic inversion center and has a slightly distorted octa-hedral coordination environment. Weak π-π stacking inter-actions, with centroid-centroid distances of 3.862 (2) and 3.887 (5) Å, and significant C-H⋯π inter-actions help to stabilize the crystal structure. The atoms of the unique terminal 4-pyridine-propane group are disordered over two sites, the ratio of refined occpancies being 0.712 (7):0.288 (7).

(E)-(2,4-Dichloro-phen-yl)[2-hydr-oxy-6-(methoxy-imino)cyclo-hex-1-en-yl]methanone.

The title compound, C(14)H(13)Cl(2)NO(3), was obtained as the product of an attempted synthesis of herbicidally active compounds containing oxime ether and cyclo-hexenone groups. In the crystal structure, the mol-ecule adopts an endocyclic enol tautomeric form and the cyclo-hexene ring adopts a distorted envelope form. The oxime ether group has an E configuration, with the meth-oxy group anti to the ortho-chloro substitutent. Intra-molecular O-H⋯O and inter-molecular C-H⋯O hydrogen bonds are found in the crystal structure.

Bi2S3 nanorod-stacked hollow microtubes self-assembled from bismuth-based metal-organic frameworks as advanced negative electrodes for hybrid supercapacitors.

Bismuth sulfide (Bi2S3) with a lamellar structure has emerged as a promising negative electrode material for supercapacitors (SCs) due to its high theoretical specific capacity. Meanwhile, the improvement of electrochemical properties strongly depends on the size, shape and morphologies of Bi2S3 nanomaterials. Herein, the hierarchical Bi2S3 nanorod-stacked hollow microtubes are self-assembled through a facile self-sacrificing template strategy from bismuth-based metal-organic framework microprisms. Benefiting from the unique structures with a large specific surface area (54.3 m2 g-1), the as-prepared Bi2S3 exhibits an ultrahigh specific capacity (532 C g-1 at 1 A g-1) as a negative electrode for SCs, outperforming other reported Bi2S3 materials.

A novel tetranuclear copper(I) sulfanide complex with bis(diphenylphosphino)amine.

The title novel mixed mu(2)-SH- and mu(3)-SH-bridged tetranuclear copper(I) complex, cyclo-bis[mu(2)-bis(diphenylphosphino)amine]di-mu(3)-sulfanido-di-mu(2)-sulfanido-tetracopper(I) methanol disolvate, [Cu(4)(SH)(4)(C(24)H(21)NP(2))(2)].2CH(3)OH, has crystallographically imposed centrosymmetry and affords a neutral Cu(4)S(4) core with a distorted step-like structure. The distances of 2.8458 (16) and 2.8179 (16) A between copper(I) centres indicate the presence of ligand-supported Cu...Cu interactions. Strong N-H...O and O-H...S hydrogen bonds between the tetranuclear cluster and methanol solvent molecules result in a two-dimensional hydrogen-bonded supramolecular network. This complex is the first example of a coinage tetranuclear metal complex with mixed mu(2)-SH- and mu(3)-SH-bridged chromophores.

Hierarchical core-shell SiO2@PDA@BiOBr microspheres with enhanced visible-light-driven photocatalytic performance.

To explore catalysts combining highly accessible specific surface areas with low recombination of the photo-induced electron-hole pairs, a novel SiO2@PDA@BiOBr composite photocatalyst with a hierarchical core-shell structure was prepared by a facile solvothermal method. The catalyst shows a superior performance on photodegradation of Rhodamine B under visible light irradiation, especially for SiO2@PDA-2@BiOBr with the reactant kinetics constant (k = 0.0487 min-1). The enhanced photocatalytic performance of SiO2@PDA-2@BiOBr was ascribed to the decreased band-gap, higher surface area, and effectively photo-generated electron-hole pairs by the introduction of polydopamine (PDA). In addition, the photocatalytic degradation is initiated by ˙O2- derived from dye photosensitization and h+ from the BiOBr. Cyclic experiments also indicate that the SiO2@PDA-2@BiOBr is reusable during the photodegradation process. The hierarchical core-shell SiO2@PDA@BiOBr photocatalyst will provide a theoretical model for the development of physical chemistry and structural properties of BiOBr-based composites to enhance the photocatalytic performances.

A hierarchical NiO/NiMn-layered double hydroxide nanosheet array on Ni foam for high performance supercapacitors.

A hierarchical NiO/NiMn-LDH nanosheet array on Ni foam was prepared via a facile two-step approach and exhibited a high specific capacitance (937 F g-1 at 0.5 A g-1) and good cycling stability (91% retention after 1000 cycles at 5 A g-1). The improved electrochemical performance is benefited from the synergistic properties of hierarchical NiO/LDH nanosheet composites on a conductive substrate.

In situ growth of ZIF-8 nanocrystals on layered double hydroxide nanosheets for enhanced CO2 capture.

A hexagonal nanosheet LDH@ZIF-8 composite was fabricated by in situ growth of ZIF-8 on Zn-Al LDH without adding any zinc precursor, and exhibited a CO2 adsorption capacity of 1.0 mmol g(-1) at room temperature and 1 bar, which was significantly higher than that of pure Zn-Al LDH or ZIF-8, indicating a synergy between ZIF-8 and Zn-Al LDH.

Enhanced photocatalytic performance of BiOBr/NH2-MIL-125(Ti) composite for dye degradation under visible light.

Metal-organic frameworks (MOFs) are considered as suitable materials for various applications in the area of photocatalysis. On the other hand, 2D BiOBr materials are efficient for the photodegradation of organic dyes under visible light illumination. In this work, BiOBr/NH2-MIL-125(Ti) composite photocatalysts with different NH2-MIL-125(Ti) content were prepared by incorporating NH2-MIL-125(Ti) with BiOBr using a co-precipitation method. A series of characterizations confirmed the strong synergistic effect between BiOBr and NH2-MIL-125(Ti). In rhodamine B (RhB) degradation experiments, the composite photocatalyst with a mass percent of 7 wt% NH2-MIL-125(Ti) exhibited an improved photocatalytic activity compared to pristine BiOBr and NH2-MIL-125(Ti). Furthermore, the enhanced photocatalytic performance under visible light illumination could be attributed to the Ti3+-Ti4+ intervalence electron transfer and synergistic effect between NH2-MIL-125(Ti) and BiOBr, and also resulted in a separation efficiency of photo-generated electron-hole pairs during the photocatalytic reaction. This study can open up numerous opportunities for the development of various MOF-based visible light photocatalysts when combined with 2D bismuth oxyhalide materials for applications in environmental cleaning.

A one-dimensional ladder-like coordination polymer derived from chains formed via hydrogen bonds: catena-poly[[aquadipyridinenickel(II)]-mu-2,2'-dithiodibenzoato-kappa3O,O':O"].

The title one-dimensional chain nickel(II)-disulfide complex, [Ni(C14H8O4S2)(C5H5N)2(H2O)]n, has each Ni(II) cation coordinated by two N atoms from two pyridine ligands, three carboxylate O atoms from two different dithiodibenzoate ligands and one O atom from a coordinated water molecule, in a distorted octahedral coordination geometry. Each dithiodibenzoate ion links two Ni(II) cations through its carboxylate O atoms, making the structure polymeric. Hydrogen-bond interactions between two shoulder-to-shoulder chains lead to the formation of a ladder-like structure.