Assembly of donor-acceptor hybrid heterostructures based on iodoplumbates and viologen coordination polymers.

The insertion of electron-rich iodoplumbate nanowires and nanolayers into layered electron-deficient metal-viologen frameworks leads to two donor-acceptor hybrid structures, respectively, which exhibit interesting semiconductor behaviors. Due to the bicontinuous donor and acceptor components, both of them exhibit highly efficient photocatalytic degradation activities over organic dyes under visible light irradiation compared to those of other iodoplumbate hybrid materials.

Construction of a bicontinuous donor-acceptor hybrid material at the molecular level by inserting inorganic nanowires into porous MOFs.

Herein, we report an unprecedented hybrid structure of electron-rich iodoplumbate nanowires precisely inserted into the periodic pores of electron-deficient pyridinium metal-organic frameworks (MOFs). To the best of our knowledge, this is the first example of semiconductive MOFs in situ loaded with inorganic semiconductive nanowires via a simple self-assembly method. Due to the dissimilar semiconductivities between the host and guest components, this hybrid also represents the first bicontinuous donor-acceptor hybrid at the molecular level based on host-guest interactions.

Encapsulating Naphthalene in an Electron-Deficient MOF to Enhance Fluorescence for Organic Amines Sensing.

Host-guest encapsulation of electron-rich naphthalene molecules into a weakly emissive porous metal-organic framework based on π-electron-deficient (π-acidic) naphthalene diimide tectons leads to orange-emissive crystals, which can be used to sense strongly basic organic amines in a fast response, high photostability, and tunable sensitivity. Moreover, such host-guest inclusion crystals are also a good photochromic probe for the detection of weakly basic N-methyl-2-pyrrolidone and N,N-dimethylformamide molecules.

Two-semiconductive-component hybrid coordination polymers with controllable photo-induced electron-transfer properties.

Two semiconductive inorganic-organic hybrid coordination polymers constructed from metal iodide clusters and naphthalene diimide semiconductive components, [Cu2I2(DPNDI)]n () and [PbI2(DPNDI)]n () (DPNDI = N,N'-di-(4-pyridyl)-1,4,5,8-naphthalene diimide), have been synthesized and characterized. Although possessing similar 2D heterostructures, hybrids exhibited different photo-induced electron-transfer properties. Due to the higher HOMO energy level of the [Cu2I2]n chain than that of the [PbI2]n cluster, only hybrid can easily undergo intramolecular electron transfer to form a long-lived charge separated state, which may be applied in artificial photosynthesis.

The impact of lone pair-π interactions on photochromic properties in 1-D naphthalene diimide coordination networks.

Lone pair-π interaction is an important but less studied binding force. Generally, it is too weak to influence the physical properties of supramolecular systems. Herein we reported the first example exhibiting the impact of lone pair-π interactions on photochromic properties of naphthalene diimide based coordination networks. In three isostructural 1-D networks, [(DPNDI)ZnX2] (DPNDI = N,N-di(4-pyridyl)-1,4,5,8-naphthalene diimide, X = Cl for 1, X = Br for 2 and X = I for 3), they exhibit different electron-transfer photochromic behaviors due to different lone pair-π interactions between the capped halogen atoms and electron-deficient DPNDI moieties. Specifically, 1 and 2 but not 3 are photochromic, which is attributed to a stronger lone pair-π interaction in 3 than those in 1 and 2. This study anticipates breaking a new path for designing novel photochromic materials through such unnoticeable supramolecular interactions.

Mixed-metal metallocavitands: a new approach to tune their electrostatic potentials for controllable selectivity towards substituted benzene derivatives.

We have successfully developed a new synthetic approach to modulate the electrostatic potentials of metallocavitands and thus their selective recognition towards substituted benzene derivatives via integrating two metal cations of different electronegativity into a self-assembled system.

A panchromatic hybrid crystal of iodoplumbate nanowires and J-aggregated naphthalene diimides with long-lived charge-separated states.

A panchromatic hybrid crystal of anionic iodoplumbate nanowires and J-aggregated protonated naphthalene diimides has been formed through charge-assisted anion-π and lone pair-π interactions, which exhibits unusually long-lived charge-separated states even upon the irradiation of indoor lighting.

Photogeneration of two reduction-active charge-separated states in a hybrid crystal of polyoxometalates and naphthalene diimides.

The combination of naphthalene diimide tectons with zinc cations in the presence of polyanions, Mo6O19(2-), leads to a hybrid crystal composed of two-dimensional porous coordination networks and polyoxometalates, which can generate two kinds of long-lived charge-separated states for the reduction reactions upon irradiation.

Lone pair-π interaction-induced generation of non-interpenetrated and photochromic cuboid 3-D naphthalene diimide coordination networks.

Interpenetration is an intrinsic behaviour for the porous coordination networks. To prevent the interpenetration, a common strategy is the imposition of geometric or steric restrictions by incorporating bulky moieties into organic tectons. So far, most of the available incorporations have been achieved through a covalent connection, while few involved in the non-covalent weak interactions. In this paper, we have reported that such interpenetration can be prevented by the less common lone pair-π interactions. By imposing the lone pair-π interactions through the addition of lone-pair-bearing N-methylpyrrolidin-2-one or iodine, combinations of rigid naphthalene diimide tectons bearing two divergently oriented pyridyl units at both imide extremities with ZnSiF6 led to non-interpenetrated cuboid 3-D coordination networks that should have been interpenetrated. In addition, such close-contacting lone pair-π interactions between electron donors and acceptors have also been demonstrated to play a key role in their photochromic properties.

A photochromic naphthalene diimide coordination network sensitized by polyoxometalates.

Metal-ion-directed assembly of naphthalene diimide tectons cooperatively enhanced by anion-π interactions of giant anions, PMo12O40(3-), leads to a novel organic-inorganic hybrid with ultrafast-responsive photochromic properties, which is attributed to the polyoxometalate-sensitized photo-induced radical generation of naphthalene diimide units.

[Molluscicidal effect of buried niclosamide sustained-release method in plateau mountainous areas].

OBJECTIVE: To evaluate the molluscicidal effect of the buried niclosamide sustained-release method in Oncomelania snail-infested terraced environments of mountainous areas in Yunnan Province. METHODS: A piece of relatively isolated snail-infested terraced environment was selected as experimental plot and randomly divided into four groups. The buried niclosamide sustained-release methods were performed in Group A, B, C with the doses of 6 g/m2, 12 g/m2, 24 g/m2 respectively, and Group D was sprayed with 50% niclosamide ethanolamine salt wettable powder (2 g/m2) as the control. RESULTS: In Group C (with the buried niclosamide sustained-release method of 24 g/m2), the half-year reduction of living snail density was 89.90%, and one-year reduction of living snail density was 96.80%, which were significantly higher than those of Group D (40.35% and 59.11%) (Both P < 0.01) CONCLUSION: The buried niclosamide sustained-release method is effective and suitable for snail control in mountainous terrace areas.

[Study of photocatalytic performance of TiO2 membrane for oleic acid by FTIR-ATR technique].

The TiO2 membranes were prepared on glass, ceramic tile and aluminum pieces by Sol-Gel and PVD methods. A fast and exact evaluation on the photocatalytic self-cleaning performance of the membrane materials was achieved by FTIR-ATR technique using oleic acid which was laid on the surface of the membrane. The hydrophilic property of the samples was also determined by the contact angle with water. The results showed that both the TiO2 membrane prepared on glass by the Sol-Gel and PVD methods displayed good photo-induced hydrophilic property and degradation activity of oleic acid, and no difference in hydrophilic property, but the former was a little superior to the latter in photocatalytic activity. The photocatalytic conversion of oleic acid on the TiO2/glass, TiO2/ceramic tile and TiO2 aluminum piece were 92%, 85% and 46%, respectively after illumination 3.5 h, showing a distinct effect of support material property on TiO2 photocatalytic performance. The results suggested that the photocatalytic activity of TiO2 membrane coated on insulator support was higher than that coated on conductor support.

[Photocatalytic functional ceramic and its speciality of photodecomposition].

Photocatalytic ceramic was prepared by coating photocatalytic membrane on ceramic matrix. The photocatalytic behavior of the TiO2 coated ceramic for degradation of oleic acid, ethylene, SO2, NOx and sterilization was studied by using XRD, chromatogram, in-situ IR and spectrophotometer. The results showed that the photocatalytic ceramic prepared by special conditions have the function of environmental conservation such as the photodegradating organic contaminants, removing inorganic baleful gas and killing bacteria. Degradation ratio of ethylene, oleic acid, SO2 and NOx reached 95%-100% respectively for the photocatalytic functional ceramic.