Search

Organic solar cells are a potential solution for sustainable energy. However, it is time-consuming and costly to discover high-efficiency materials for organic solar cells. In this study, a deep learning-based framework (DeepDonor) has been developed to find high-performance donor materials. Specifically, a small molecule (SM) dataset and a polymer molecule (PM) dataset were collected from the literature. Then, the quantum deep field (QDF) model and transfer learning method were used to predict the power conversion efficiency (PCE). Results show that DeepDonor significantly outperforms other common methods with r = 0.82 and MAE = 1.67% on the SM test set, and r = 0.77 and MAE = 1.59% on the PM test set. These models can predict PCE with great accuracy, extrapolation performance, and transferability. Then, a molecule generation and screening strategy was proposed to discover high-performance polymer donors with the help of DeepDonor. Two discovered candidates were further validated by experiments, and their PCE reached 16.27% and 15.07%, respectively. The released online interface of DeepDonor substantially boosts the accessibility and efficiency of designing and discovering high-performance donors. In sum, DeepDonor is a promising method to predict the PCE and speed up the discovery of high-performance donor materials. [ABSTRACT FROM AUTHOR]

The construction of low-symmetry topological supramolecular structures using bistable building blocks remains challenging. We report an unusual truncated triangular prismatic cage with D3h symmetry using a ligand with both cis- and trans-configurations upon coordination with metal. This work provides new ideas and methods for the future synthesis of low-symmetry topological supramolecules. [ABSTRACT FROM AUTHOR]

Electrochemical nitrate (NO3−) reduction is a sustainable pathway for ambient ammonia (NH3) synthesis while eliminating NO3− pollutants in water. However, the NO3− reduction reaction (NO3−RR) involves a complicated eight-electron transfer process, which needs highly selective and efficient electrocatalysts. This work describes the synthesis of Fe3O4 nanoparticle-decorated 3D pinewood-derived carbon (Fe3O4/PC) as a high-efficiency catalyst for the electroreduction of NO3− to NH3 at ambient reaction conditions. When tested in 0.1 M NaOH containing 0.1 M NO3−, the Fe3O4/PC obtains a large NH3 yield of 394.8 μmol h−1 cm−2 and high faradaic efficiency (FE) of 91.6% at −0.4 V. Significantly, Fe3O4/PC also delivers high stability. [ABSTRACT FROM AUTHOR]

Herein, a novel 3D metal–organic ligand consisting of a folded Ru(II)-connected tetrameric cycle and two sets of 60° juxtaposed bisterpyridine arms was synthesized and its complexation with Zn2+ gave rise to dendritic-faced metallo-octahedron 6. Remarkably, octahedron 6 displayed unexpected photosensitization ability that could produce singlet oxygen (1O2) under white light irradiation. [ABSTRACT FROM AUTHOR]

Water-stable anionic Ln2L2-type (Ln = LaIII and EuIII) lanthanide–organic macrocycles have been constructed by deprotonation self-assembly of a bis-tridentate ligand consisting of two 2,6-bis-(1,2,4-triazole)-pyridine chelation arms bridged by a dibenzofuran chromophore, of which the luminescent Eu2L2 macrocycle can be used for enantiomeric excess (ee) detection toward pybox-type chiral ligands and selective colorimetric sensing of omethoate (OMA) in water. [ABSTRACT FROM AUTHOR]

A facile incorporation of a privileged sulfide, a naphthofuran framework, and a perfluoroalkyl moiety in one molecule was successfully accomplished through tandem defluorinative sulfenylation of α-perfluoroalkyl ketones with a sulfur source. The reaction presumably proceeds via a sequence involving defluorination, reductive sulfenylation, autoaromatization, and annulation, accompanied by the simultaneous cleavage of four C(sp3)–F bonds and the formation of new C–S and C–O bonds. [ABSTRACT FROM AUTHOR]

Macrocycle-based architectures are of importance in synthetic chemistry. Here, a novel parallelogram metallomacrocycle Fe2(LA)2 with reversible structural transformation was designed and synthesized. The template-free metalla[2]catenane [Fe2(LA)2]2 could be obtained by changing the concentration and has been monitored on the basis of NMR analysis. By redesigning the metallo-ligand, a catenane-like intersected parallelogram assembly with two shape-persistent supramolecular isomers was achieved. This work develops the field of terpyridine-based macrocycle system research and is valuable for obtaining other types of supramolecular isomerism. [ABSTRACT FROM AUTHOR]

Hg2+ is highly toxic and hazardous and widely found in polluted water. To remove mercury ions from wastewater, there is an urgent need to investigate and develop new adsorbents. Herein, we synthesized three novel thioether-based metal–organic frameworks (MOFs) through a facile diffusion method or a solvothermal strategy, i.e. [(ZnCl2)3(L1)2·χ(solvent)]n (1), [(Cu2I3O2)4(CH4N0.5)4(L1)4(DMA)4·3(H2O)·χ(solvent)]n (2) and [(CuBr2)2(L2)2 CH3CN·χ(solvent)]n (3), where L1 = 1,3,5-tris((pyridin-4-ylthio)methyl)benzene and L2 = 2,4,6-trimethoxy-1,3,5-tris((pyridin-4-ylthio)methyl)benzene. The obtained thioether-based MOFs were characterized by single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis. Further studies revealed that they could remove Hg2+ from water. They have high adsorptivity (up to 362 mg g−1) and are highly efficient in removing Hg2+ (up to 95%). Besides, these MOFs can be recycled and can selectively remove Hg2+ from water in the presence of other metal ions. Consequently, these MOFs are highly promising candidates for the selective absorption and removal of mercury ions from water. [ABSTRACT FROM AUTHOR]

We demonstrate a unique negative solvatochromic emission (NSE) process from a conformational change of a coordination cage in response to solvent composition. The cationic cage contains two tetra-(4-pyridylphenyl)ethylene (TPPE) luminogens on two opposite faces, linked by Pt(PEt3)2 and isophthalate. When the solvent changes from acetone/acetonitrile/methanol to water, the emission of single cages gradually shifts to short wavelength (NSE) with a drastic value of ∼60 nm. Small angle X-ray scattering (SAXS) measurements indicate a molecular conformational change during the process and intramolecular π–π stacking and hydrophobic interaction between the TPPE planes could be the driving forces. As a comparison, a cage with a longer inter-fluorophore distance does not have such strong intramolecular interactions and only shows regular positive solvatochromic emission (PSE) under the same conditions. [ABSTRACT FROM AUTHOR]

We present a Ag(i)/Co(ii) co-catalyzed tandem fragmentation and recombination reaction commencing from detachable nonaflates and amidines. This catalytic method offers a unique and expeditious access to various fluoroalkylated dihydrobenzo[h]quinazolines and benzo[h]quinazolines in the absence of external fluorine sources through a rationally designed radical desulfonylation, migration, defluorination, and polar condensation relay. [ABSTRACT FROM AUTHOR]

Hierarchical construction of a highly ordered supramolecular array has been, in general, a challenge due to the complexation of building blocks and the hard-to-control weak interactions. Herein, we present a type of well-ordered nanoribbon, which was self-assembled via shape complimentary and hydrophobic effects from the bowl-shaped supramolecular components, which were synthesized by combining designer terpyridine-based monomers and two different metal ions (Ru2+, Zn2+). Interestingly, switching counter ions or changing monomer concentrations, a transformation between a uniform nanosphere and nanoribbon occurred. This opens a door to fabricate readily tailorable, large-scale, supramacromolecular materials. [ABSTRACT FROM AUTHOR]

A novel terpyridine-based, trapezoidal architecture was synthesized by a coordination-driven multicomponent assembly and features three different tpy–M2+–tpy bonds (M2+ = Ru2+, Fe2+, and Zn2+) in the macrocyclic ring. This trimetallic macrocycle introduces the construction of polymetallosupramolecular assemblies possessing multiple, differing metal centers in an ordered, predetermined pattern. Characterization was accomplished by NMR spectroscopy, mass spectrometry, and UV-Vis spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, a promising preparation strategy for antibacterial silk sutures with an l-lysine based nanogel grafting is reported. The triclosan-loaded nanogels (NGTLs) were fabricated by the convenient enzymatic degradation of macrogels, namely, triclosan-loaded macrogel, degrading into NGTLs triggered by the trypsin. Nanogels, about 60 nm and 90 nm in diameter, were obtained after 7 days of biodegradation in the enzyme solution. Triclosan maintained a sustained release period over 260 hours in trypsin solution with the concentration of 0.1 mg mL−1. Triclosan-loaded nanogel grafted silk sutures (TLNGSs) were characterized by an antibacterial activity assessment. Our results showed that TLNGS had long-term efficacy against pathogens such as S. aureus and E. coli. In particular, these TLNGSs had a relative decreased stable size of inhibition zones on agar plates in the first four days. The antibacterial activity could be sufficient evidence of the prevention of potential early wound infections. The mechanical strength tests indicated negligible influence on TLNGSs compared to commercial ones. The novel antibacterial silk sutures showed acceptable in vitro cytotoxicity according to ISO 10993-5. This novel biocompatible and biodegradable nanogel grafting to silk sutures provides an effective and universal approach for the treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

A Bi2O3 nanoparticle modified BiOCl composite was synthesized by a solvothermal method combined with in situ reduction and oxidation in KBH4 and H2O2 solutions respectively. The thickness of a BiOCl nanosheet and the amount of Bi2O3 nanoparticle can be adjusted by changing the KBH4 concentration. The structure, morphology, elemental composition and optical absorption performance were characterized by using an X-ray diffraction diffractometer, a scanning electron microscope, a high resolution transmission electron microscope, an X-ray photoelectron spectroscope and a UV-Vis diffuse reflection spectroscope respectively. A nanolayered hierarchical structure of BiOCl was observed, and Bi2O3 nanoparticles were found to be evenly distributed on the surface/interface of the nanosheets. The photocatalytic activity of the composite was tested by the degradation of 40 mg L−1 methyl orange solution under UV light illumination. The Bi2O3/BiOCl composite prepared in a KBH4 concentration of 0.02 M achieved the highest photocatalytic rate of 95.7% in 8 min under UV light illumination with a kinetic constant of 0.3125 l min−1. The photocatalytic mechanism of the composite has been discussed. [ABSTRACT FROM AUTHOR]

A composite cathode based on redox-stable La0.2Sr0.8TiO3+δ (LSTO) can perform direct carbon dioxide electrolysis; however, the insufficient electro-catalytic activity limits the electrode performances and current efficiencies. In this work, catalytically active scandium is doped into LSTO to enhance the electro-catalytic activity for CO2 electrolysis. The structures, electronic conductivities and ionic conductivities of La0.2Sr0.8Ti1−xScxO (LSTSxO) (x = 0, 0.05, 0.1, 0.15 and 0.2) are systematically studied and further correlated with electrode performances. The ionic conductivities of single-phase LSTSxO (x = 0, 0.05, 0.1 and 0.15) remarkably improve versus the scandium doping contents though the electrical conductivities gradually change in an adverse trend. Electrochemical measurements demonstrate promising electrode polarisation of LSTSxO electrodes and increasing scandium doping contents accordingly improve electrode performances. The Faradic efficiencies of carbon dioxide electrolysis are enhanced by 20% with LSTS0.15O in contrast to bare LSTO electrodes in a solid oxide electrolyser at 800 °C. [ABSTRACT FROM AUTHOR]

Bi nanoparticles are grown on BiOCl nanosheets via an in situ chemical reduction in a KBH4 aqueous solution. Bi/BiOCl nanosheets with different contents of Bi nanoparticles can be achieved by changing the concentration of the KBH4 solution. The structure, morphology, elemental composition and optical absorption performance are characterized using an X-ray diffraction diffractometer, a scanning electron microscope, a high resolution transmission electron microscope, an X-ray photoelectron spectrometer and a UV-Vis diffuse reflection spectrometer. The photocatalytic activities of the as-prepared photocatalysts are tested using the degradation of methyl orange under both UV light and visible light irradiation. Bi nanoparticles modified on BiOCl nanosheets not only enhance the photocatalytic activity under UV light irradiation, but also achieve visible light photocatalytic activity. The mechanism of the photocatalytic processes, such as optical absorption, charge transfer and surface reactions, for the Bi/BiOCl nanosheets are discussed in detail. [ABSTRACT FROM AUTHOR]

Heterojunction composites based on n-type TiO2 nanotubes arrays (TNAs) coupled with p-type Cu2O nanoparticles were synthesized using a square wave voltammetry deposition method for in situ deposition of Cu2O nanoparticles onto the inner surfaces and interfaces of TNAs. The prepared samples were characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis spectroscopy. When compared with pure TNAs, the Cu2O–TNAs heterojunction composites exhibit considerably higher photocurrent density under visible-light irradiation and enhanced photocatalytic activity for the visible-light-driven photodegradation of methyl orange. Moreover, the photocurrent densities and photocatalytic activity of the Cu2O–TNAs heterostructures largely depend on the deposition potential which determines the content of the Cu2O nanoparticles. The Cu2O–TNAs prepared by the deposition potential of −1.0 V showed the highest photocurrent density (0.91 mA cm−2) and the largest photodegradation rate of methyl orange (88.8%) at the applied potential of 0.5 V under visible light irradiation. The enhanced photoelectrocatalytic activity can be attributed to reducing the recombination rate of the photoexcited electron–hole pairs in TNAs when coupled with Cu2O nanoparticles. [ABSTRACT FROM AUTHOR]

The formation of metallo-cages is affected by a variety of factors such as the ligands, metals, and anions, among which the impact of metals with different binding capacities is particularly important, but has rarely been studied in three-dimensional metallo-cages. Herein, we report the design of truxene-centered terpyridine ligands and the self-assembly of a series of tetrameric metallo-cages. The utilization of metal ions with strong (Zn 2+ , Fe 2+ ) or weak (Cd 2+ ) binding strength afforded 3D metallo-cages with low symmetry or highly symmetric metallo-tetrahedra, respectively, possessing totally different geometrical configurations. In addition, their photophysical properties and host-guest chemical properties were investigated.

The construction of low-symmetry topological supramolecular structures using bistable building blocks remains challenging. We report an unusual truncated triangular prismatic cage with D 3h symmetry using a ligand with both cis - and trans -configurations upon coordination with metal. This work provides new ideas and methods for the future synthesis of low-symmetry topological supramolecules.

Electrochemical nitrate (NO 3 - ) reduction is a sustainable pathway for ambient ammonia (NH 3 ) synthesis while eliminating NO 3 - pollutants in water. However, the NO 3 - reduction reaction (NO 3 - RR) involves a complicated eight-electron transfer process, which needs highly selective and efficient electrocatalysts. This work describes the synthesis of Fe 3 O 4 nanoparticle-decorated 3D pinewood-derived carbon (Fe 3 O 4 /PC) as a high-efficiency catalyst for the electroreduction of NO 3 - to NH 3 at ambient reaction conditions. When tested in 0.1 M NaOH containing 0.1 M NO 3 - , the Fe 3 O 4 /PC obtains a large NH 3 yield of 394.8 μmol h -1 cm -2 and high faradaic efficiency (FE) of 91.6% at -0.4 V. Significantly, Fe 3 O 4 /PC also delivers high stability.

Herein, a novel 3D metal-organic ligand consisting of a folded Ru(II)-connected tetrameric cycle and two sets of 60° juxtaposed bisterpyridine arms was synthesized and its complexation with Zn 2+ gave rise to dendritic-faced metallo-octahedron 6. Remarkably, octahedron 6 displayed unexpected photosensitization ability that could produce singlet oxygen ( 1 O 2 ) under white light irradiation.

Water-stable anionic Ln2L2-type (Ln = LaIII and EuIII) lanthanide-organic macrocycles have been constructed by deprotonation self-assembly of a bis-tridentate ligand consisting of two 2,6-bis-(1,2,4-triazole)-pyridine chelation arms bridged by a dibenzofuran chromophore, of which the luminescent Eu2L2 macrocycle can be used for enantiomeric excess (ee) detection toward pybox-type chiral ligands and selective colorimetric sensing of omethoate (OMA) in water.

Hg 2+ is highly toxic and hazardous and widely found in polluted water. To remove mercury ions from wastewater, there is an urgent need to investigate and develop new adsorbents. Herein, we synthesized three novel thioether-based metal-organic frameworks (MOFs) through a facile diffusion method or a solvothermal strategy, i.e. [(ZnCl 2 ) 3 (L 1 ) 2 ·χ(solvent)] n (1), [(Cu 2 I 3 O 2 ) 4 (CH 4 N 0.5 ) 4 (L 1 ) 4 (DMA) 4 ·3(H 2 O)·χ(solvent)] n (2) and [(CuBr 2 ) 2 (L 2 ) 2 CH 3 CN·χ(solvent)] n (3), where L 1 = 1,3,5-tris((pyridin-4-ylthio)methyl)benzene and L 2 = 2,4,6-trimethoxy-1,3,5-tris((pyridin-4-ylthio)methyl)benzene. The obtained thioether-based MOFs were characterized by single-crystal X-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis. Further studies revealed that they could remove Hg 2+ from water. They have high adsorptivity (up to 362 mg g -1 ) and are highly efficient in removing Hg 2+ (up to 95%). Besides, these MOFs can be recycled and can selectively remove Hg 2+ from water in the presence of other metal ions. Consequently, these MOFs are highly promising candidates for the selective absorption and removal of mercury ions from water.

SmI 2 -mediated reductive cyclization of β-arylthio ketones to generate thiochroman derivatives is not a generally observed process and the reported examples are limited to geminal disubstitution in the substrates. The results of the current study show that the cyclization also occurs when other substitution patterns are present, affording a general approach to dihydrothiochroman-ols in good yields and high degrees of diastereoselectivity. Besides, the halogen substitution on β-aryl is tolerated in most cases here although reductive dehalogenation has been reported to predominate in the reductive cyclization process. Dihydrothiochroman-4-ols were readily oxidized to thiochroman-4-ols in almost quantitative yields.

A Bi2O3 nanoparticle modified BiOCl composite was synthesized by a solvothermal method combined with in situ reduction and oxidation in KBH4 and H2O2 solutions respectively. The thickness of a BiOCl nanosheet and the amount of Bi2O3 nanoparticle can be adjusted by changing the KBH4 concentration. The structure, morphology, elemental composition and optical absorption performance were characterized by using an X-ray diffraction diffractometer, a scanning electron microscope, a high resolution transmission electron microscope, an X-ray photoelectron spectroscope and a UV-Vis diffuse reflection spectroscope respectively. A nanolayered hierarchical structure of BiOCl was observed, and Bi2O3 nanoparticles were found to be evenly distributed on the surface/interface of the nanosheets. The photocatalytic activity of the composite was tested by the degradation of 40 mg L(-1) methyl orange solution under UV light illumination. The Bi2O3/BiOCl composite prepared in a KBH4 concentration of 0.02 M achieved the highest photocatalytic rate of 95.7% in 8 min under UV light illumination with a kinetic constant of 0.3125 l min(-1). The photocatalytic mechanism of the composite has been discussed.

Composite cathodes based on Sr0.94Ti0.9Nb0.1O3 (STNO) can be utilized for direct steam electrolysis; however, the insufficient electrocatalytic activity limits electrode performance and current efficiency. In this work, redox-reversible (Sr0.94)0.9(Ti0.9Nb0.1)0.9Ni0.1O3 (STNNO) with A-site deficiency and B-site excess has been designed as a cathode material in an oxide-ion-conducting solid oxide electrolyzer for direct steam electrolysis. The XRD, TEM, SEM, EDS, TGA and XPS results together confirm that the exsolution or dissolution of Ni nanoparticles anchored on the STNO surface is completely reversible in the redox cycles. The electrical properties of STNO and STNNO are investigated and correlated to electrode performances. The current efficiency with an STNNO cathode is enhanced by about 20% compared to the values with a bare STNO cathode in 5% H2O/H2/Ar or 5% H2O/Ar at 800 °C. The synergetic effect of catalytically active nickel nanoparticles and the redox-stable STNO skeleton contributes to the improved performance and excellent stability of the cathode for steam electrolysis.

The highly dispersed Ni nanoparticles in mesoporous silica were achieved via using polyol as new delivery conveyors and removable carbon templates. The catalyst exhibits excellent coking- and sintering-resistance in dry reforming of methane attributed to the controlled size and location of Ni nanoparticles.

We devised a new ratiometric fluorescent probe for the detection of chloride ions. This synthesized probe was applied to the ventricular myocytes to successfully realize dynamic imaging of Cl(-) concentration fluctuations during the myocardial ischemia course., (This journal is © The Royal Society of Chemistry 2012)

The first near-infrared fluorescent probe was developed toward Cu(2+). Based on the photo-induced electron transfer (PET) mechanism, the probe exhibited weak fluorescence. Upon the addition of Cu(2+), it fluoresced strongly. The probe offered this unique capability, and was successfully applied to living cells, tissues and in vivo to visualize Cu(2+).

By employing different diimine complexes and a naphthanoimidazolate (L(1)) or benzoimidazolate (L(2)) anion ligand as linker, a series of trimetallo-macrocycles have been synthesized through a directed self-assembly approach that involves spontaneous deprotonation of the ligands in aqueous solution. Some compounds, namely, [M(3)L(3)](NO(3))(3) (M = (18-crown-6-phen)Pt, 1 or 7; (15-crown-5-phen)Pt, 2; (benzo-24-crown-8-phen)Pt, 8; (benzo-24-crown-8-phen)Pd, 9; (15-crown-5-phen)Pd, 4 or 11; (18-crown-6-phen)Pd, 3 or 10; (dmbpy)Pd, 6 or 14; (bpy)Pd, 5 or 13; (bpy)Pt, 12; (N4-Phen)Pd, 15) were synthesized. In all of these compounds, the L(1)or L(2) anion ligands are in a syn, syn, syn orientation which result in a bowl-like cavity that can serve as a host to bind the methyl of a solvent CH(3)CN within the naphthanoimidazolate or benzoimidazolate-built cavity through C-H...pi hydrogen bonds in the crystal state. The structures are characterized by elemental analysis, (1)H NMR, ESI-MS, and in the cases of 4a, 11, 13, and 14a by single-crystal X-ray diffraction analysis.