A composite material, {Fe(L)(TPPE)0.5⋅3 CH3OH}n, has been constructed by integrating the spin‐crossover (SCO) subunit ...FeII{diethyl(E,E)‐2,2′‐1,2‐phenyl‐bis(iminomethylidyne)bis(3‐oxobutanoate)‐(2‐)‐N,N′,O3,O3′} and the highly luminescent connector 1,1,2,2‐tetrakis(4‐(pyridin‐4‐yl)phenyl)‐ethene. Its structure contains four staggered 4×4 layers and intercalated methanol. The packing is dominated by considerable H‐bonds either between adjacent layers and between layers and guests. A crystal‐structure transformation was detected upon removal of the guest molecules. The SCO transition of the solvated crystals is centered at ca. 215 K with a non‐symmetrical hysteresis of 25 K wide, and the desolvated Fe(L)(TPPE)0.5n exhibits gradual SCO without hysteresis. Intriguingly, the intensity of the fluorescence at 460 nm for the latter is maximized at the SCO transition. The energy transfer between luminescent and SCO entities is achievable as confirmed by theoretical calculations.
A square‐grid layered FeII coordination polymer based on a luminophore connector TPPE was studied. This framework not only features a solvent‐dependent structure and spin crossover (SCO) behavior, but also exhibits a switch between spin transition and fluorescence for the guest‐free species. Theoretical calculation reveals an energy‐transfer mechanism.
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•Microplastics monitoring data in soil systems are currently insufficient.•Standardized analytical methods for soil microplastics are still lacking.•Microplastics can affect soil ...physicochemical properties and biota.•Future studies on occurrence and impacts of microplastics in soils are required.
The wide and intensive application of plastics and their derived products has resulted in global environmental contamination of plastic waste. Large-sized plastic litter can be fragmented into microplastics (<5 mm), which have attracted increasing concerns from the general public and scientific communities worldwide. Until recently, the majority of microplastics research reported in literatures has been focusing on the aquatic settings, especially the marine environment, while information about microplastics contamination in terrestrial soil systems is highly insufficient. In this paper, we reviewed the latest data regarding the occurrence of microplastics in terrestrial soils and discussed their potential pathways into the soil environment. We also summarized the currently used methodologies for extraction and characterization of microplastics in soil matrices and evaluated their advantages and limitations. Additionally, we assessed the ecotoxicological consequences of microplastics contamination on soil ecosystems, including the effects on soil physiochemical properties, terrestrial plants, soil fauna, and soil microbes. Finally, based on the most current progress summarized in this review, we suggested several directions for future research on microplastics in soil ecosystems.
The prevalence of microplastics in aquatic environments has raised concerns about their availability and risks to aquatic biota. Since fish is an important source of animal protein for human beings, ...the occurrence and potential impacts of microplastics in fishes deserve special attention. Although there have been an increasing number of studies concerning microplastics ingestion and effects in fish, review papers specifically focusing on this issue are few. This review summarized the current knowledge about the bioavailability and toxicity of microplastics to fish species. By collating literatures, it can be concluded that microplastics contamination could occur in almost all types of aquatic habitats around the globe. Both field and laboratory studies suggest that fishes are very susceptible to microplastics ingestion. Compared with marine species, freshwater fishes have been less studied. Microplastics alone or in combination with other contaminants could cause various health problems to fish after exposure. There still exist some debates over the environmental relevance of the laboratory-based effect studies and the relative contribution of microplastics in increasing the exposure of fish to hazardous chemicals. Hopefully, this review could extend the current knowledge on the ecotoxicological impacts of microplastics contamination to fish and provide guidance for future research.
•Microplastics are pervasive in global waters.•Ingestion of microplastics by fish widely occurs in natural aquatic environments.•Exposure to microplastics could cause various health problems to fish.•Microplastics are potential carriers of adhered contaminants to fish.
A major challenge is the development of multifunctional metal–organic frameworks (MOFs), wherein magnetic and electronic functionality can be controlled simultaneously. Herein, we rationally ...construct two 3D MOFs by introducing the redox active ligand tetra(4‐pyridyl)tetrathiafulvalene (TTF(py)4) and spin‐crossover FeII centers. The materials exhibit redox activity, in addition to thermally and photo‐induced spin crossover (SCO). A crystal‐to‐crystal transformation induced by I2 doping has also been observed and the resulting intercalated structure determined. The conductivity could be significantly enhanced (up to 3 orders of magnitude) by modulating the electronic state of the framework via oxidative doping; SCO behavior was also modified and the photo‐magnetic behavior was switched off. This work provides a new strategy to tune the spin state and conductivity of framework materials through guest‐induced redox‐state switching.
A 3D FeII metal–organic framework (MOF) based on the tetrathiafulvalene tetrapyridyl ligand and its I2‐doped analogue were prepared. The TTF moieties provide redox activity, and I2 doping improves the conductive properties. Doping or light irradiation significantly alters the magnetic properties, indicating the material has electronically and photo‐switchable spin‐crossover properties.
Metal-organic frameworks (MOFs) that respond to external stimuli such as guest molecules, temperature, or redox conditions are highly desirable. Herein, we coupled redox-switchable properties with ...breathing behavior induced by guest molecules in a single framework. Guided by topology, two flexible isomeric MOFs, compounds 1 and 2, with a formula of In(Me
NH
)(TTFTB), were constructed via a combination of In(COO)
metal nodes and tetratopic tetrathiafulvalene-based linkers (TTFTB). The two compounds show different breathing behaviors upon the introduction of N
. Single-crystal X-ray diffraction, accompanied by molecular simulations, reveals that the breathing mechanism of 1 involves the bending of metal-ligand bonds and the sliding of interpenetrated frameworks, while 2 undergoes simple distortion of linkers. Reversible oxidation and reduction of TTF moieties changes the linker flexibility, which in turn switches the breathing behavior of 2. The redox-switchable breathing behavior can potentially be applied to the design of stimuli-responsive MOFs.
Herein, we report a cobalt‐catalyzed hydroarylation of maleimides followed by an annulation sequence for the synthesis of polycyclic azaheterocycles in one pot. The reaction proceeds under ...redox‐neutral conditions and is compatible with various functional groups. Notably, the as‐prepared product exhibits potential photophysical properties.
Organic ultralong room‐temperature phosphorescence (RTP) materials have attracted great attention for their wide applications in optoelectronic devices and bioimaging. However, the development of ...these materials remains a challenging task, partially due to the lack of rational molecular design strategies and unclear luminescence mechanisms. Herein, we present a method for facile access to structurally diverse substituted 1‐aminoisoquinoline derivatives through a copper‐catalyzed one‐pot three‐component coupling reaction that provides a promising approach to rapidly assemble a library of 1‐aminoisoquinolines for exploring the regularity of the host‐guest doped system. A series of host‐guest RTP materials with wide‐ranging lifetimes from 4.4 to 299.3 ms were constructed by doping various substituted isoquinolines derivatives into benzophenone (BP). Furthermore, 4 r/BP nanoparticles could be used for in‐vivo imaging with a signal‐to‐noise ratio value as high as 32, revealing the potential of the isoquinoline framework for the construction of high‐performance RTP materials.
A convenient, efficient and direct approach toward structurally diverse substituted 1‐aminoisoquinoline derivatives has been developed. By simply doping the 1‐aminoisoquinolines into benzophenone (BP), a series of RTP systems with tunable lifetime luminescence can be realized. 4 r/BP nanoparticles could be used for in‐vivo imaging with a high signal‐to‐noise ratio.
Researchers often examine hydro-climatological processes via Global Circulation Model (GCM) and hydrological model, which have been shown to benefit water resources management and prediction, ...especially at the basin scale. In this study, the Soil and Water Assessment Tool (SWAT) and Statistical Downscaling Method (SDSM) were integrated and applied to estimate streamflows in the Xin River Basin, China, based on climate change scenarios downscaled from different GCMs (BCC-CSM1.1, CanESM2, and NorESM1-M) under three Representative Concentration Pathways (RCPs). Results confirmed that the calibrated SWAT model accurately depicts hydrological processes features at daily, monthly, and yearly scales. Three GCMs based on the calibrated SDSM showed that temperature is continually increasing in the region, however, future precipitation is highly complex and uncertain; there were significant differences among various GCM RCP scenarios. The average of the precipitation in three models showed slight and steady increase trends under RCP2.6 and RCP4.5, but a significant increase under the RCP8.5 scenario. The ensemble average of streamflow in GCMs demonstrated that many RCPs significantly decrease from May to June but increase from August to September relative to the baseline period. The ensemble mean of the multi-GCM indicated that future streamflows under RCP2.6 and RCP4.5 scenarios will be closer to the current streamflow volume. Many RCPs also revealed a significant increase in monthly streamflow dispersion coefficient in October, reflecting a tendency for drought and flood events in that month. The BCC-CSM1.1 and NorESM1-M models showed that streamflows are higher than the baseline with median probability in the future. The low monthly streamflow (10th percentile) processes for each GCM were altogether similar to the baseline, whereas the high monthly streamflows (90th percentile) showed various levels of disparity compared to the baseline.
•Climate data was projected from three CMIP5 GCMs under RCP scenarios using a statistical downscaling model.•Future streamflow was modeled through the calibrated SDSM and SWAT models.•We compared streamflow characteristics in three future periods of the RCPs.
Using the redox‐active tetrathiafulvalene tetrabenzoate (TTFTB4−) as the linker, a series of stable and porous rare‐earth metal–organic frameworks (RE‐MOFs), RE9(μ3‐OH)13(μ3‐O)(H2O)9(TTFTB)3 (1‐RE, ...where RE=Y, Sm, Gd, Tb, Dy, Ho, and Er) were constructed. The RE9(μ3‐OH)13(μ3‐O) (H2O)9(CO2)12 clusters within 1‐RE act as segregated single‐molecule magnets (SMMs) displaying slow relaxation. Interestingly, upon oxidation by I2, the S=0 TTFTB4− linkers of 1‐RE were converted into S=1/2
TTFTB.3− radical linkers which introduced exchange‐coupling between SMMs and modulated the relaxation. Furthermore, the SMM property can be restored by reduction in N,N‐dimethylformamide. These results highlight the advantage of MOFs in the construction of redox‐switchable SMMs.
Redox switchable single‐molecule magnets (SMM) arranged in ordered architectures are valuable objects for use in memory devices. A metal–organic framework is an ideal platform to integrate SMM as nodes and redox‐active organic linkers as switching probes (see figure).
Two transition metal complexes {Co
2
(bpda)
4
(H
2
O)
2
·4H
2
O}
n
(Co-
1
) and {Ni(bpda)
2
(H
2
O)
2
·2H
2
O}(Ni-
2
) (H
2
bpda = 2,2′-bipyridine-4,4′-dicarboxylic acid) have been synthesized by a ...hydrothermal method and characterized. These two compounds can be explored as stable electrocatalysts in the hydrogen evolution reaction (HER) using two important parameters: the overpotential and Tafel slope (TS). Electrochemical studies suggest that the reaction kinetics of a Co-
1
catalyst is more favorable than that of a Ni-
2
catalyst. Co-
1
exhibits better HER performance with an overpotential of 182 mV at a current density of 10 mA cm
−2
, a small TS of 87.21 mV dec
−1
and superior long-term durability (of up to 3000 cycles). Structural analysis shows that its catalytic activity is improved due to the two mixed valence cobalt ions and the pore structure formed by hydrogen bonds in Co-
1
, which is different from that of Ni-
2
. In addition, the mechanism of the HER is also explained theoretically by DFT molecular orbital and free energy calculations in this article.
Co-
1
exhibits a three-dimensional pore structure through hydrogen bonding and π-conjugation, providing a platform for efficient charge carrier mobility and the hydrogen evolution reaction.
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