| 1. |
- Barai, Manas, et al.
(författare)
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Physicochemical Studies on Amino Acid Based Metallosurfactants in Combination with Phospholipid
- 2024
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X.
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Tidskriftsartikel (refereegranskat)abstract
- Dicarboxylate metallosurfactants (AASM), synthesized by mixing N-dodecyl aminomalonate, -aspartate and -glutamate with CaCl2, MnCl2 and CdCl2, were characterized by XRD, FTIR, and NMR spectroscopy. Layered structures, formed by metallosurfactants, were evidenced from differential scanning calorimetry and thermogravimetric analyses. Solvent-spread monolayer of AASM in combination with soyphosphatidylcholine (SPC) and cholesterol (CHOL) were studied using Langmuir surface balance. With increasing mole fraction of AASM mean molecular area increased and passed through maxima at ~60 mol% of AASMs, indicating molecular packing reorganization. Systems with 20 and 60 mol% AASM exhibited positive deviations from ideal behavior signifying repulsive interaction between the AASM and SPC, while synergistic interactions were established from the negative deviation at other combinations. Dynamic surface elasticity increased with increasing surface pressure signifying formation of rigid monolayer. Transition of monolayer from gaseous to liquid expanded to liquid condensed state was established by Brewster angle microscopic studies. Stability of the hybrid vesicles, formed by AASM+SPC+CHOL, was established by monitoring their size, zeta potential and polydispersity index values over 100 days. Size and spherical morphology of hybrid vesicles were confirmed by transmission electron microscopic studies. Biocompatibility of the hybrid vesicles were established by cytotoxicity studies revealing their possible applications in drug delivery and imaging.
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| 2. |
- Biswas, Srijit, et al.
(författare)
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The Efficiency of the Metal Catalysts in the Nucleophilic Substitution of Alcohols is Dependent on the Nucleophile and Not on the Electrophile
- 2013
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 8:5, s. 974-981
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigate the effect of the electrophiles and the nucleophiles for eight catalysts in the catalytic SN1 type substitution of alcohols with different degree of activation by sulfur-, carbon-, oxygen-, and nitrogen-centered nucleophiles. The catalysts do not show any general variance in efficiency or selectivity with respect to the alcohols and follow the trend of alcohol reactivity. However, when it comes to the nucleophile, the eight catalysts show general and specific variances in the efficiency and selectivity to perform the desired substitution. Interestingly, the selectivity of the alcohols to produce the desired substitution products was found to be independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation. Catalysts based on iron(III), bismuth(III), and gold(III) show higher conversions for S-, C-, and N-centered nucleophiles, and BiIII was the most efficient catalyst in all combinations. Catalysts based on rhenium(I) or rhenium(VII), palladium(II), and lanthanum(III) were the most efficient in performing the nucleophilic substitution on the various alcohols with the O-centered nucleophiles. These catalysts generate the symmetrical ether as a by-product from the reactions of S-, C-, and N-centered nucleophiles as well, resulting in lower chemoselectivity.
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| 3. |
- Chai, Zhigang
(författare)
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Light-Driven Alcohol Splitting by Heterogeneous Photocatalysis : Recent Advances, Mechanism and Prospects
- 2021
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X. ; 16:5, s. 460-473
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Forskningsöversikt (refereegranskat)abstract
- Splitting of alcohols into hydrogen and corresponding carbonyl compounds, also called acceptorless alcohol dehydrogenation, is of great significance for both synthetic chemistry and hydrogen production. Light-Driven Alcohol Splitting (LDAS) by heterogeneous photocatalysis is a promising route to achieve such transformations, and it possesses advantages including high selectivity of the carbonyl compounds, extremely mild reaction conditions (room temperature and irradiation of visible light) and easy separation of the photocatalysts from the reaction mixtures. Because a variety of alcohols can be derived from biomass, LDAS can also be regarded as one of the most sustainable approaches for hydrogen production. In this Review, recent advances in the LDAS catalyzed by the heterogeneous photocatalysts are summarized, focusing on the mechanistic insights for the LDAS and aspects that influence the performance of the photocatalysts from viewpoints of metallic co-catalysts, semiconductors, and metal/semiconductor interfaces. In addition, challenges and prospects have been discussed in order to present a complete picture of this field.
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| 4. |
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| 5. |
- Cheruku, Pradeep, et al.
(författare)
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Phosphine-Free Cp*Ru(Diamine) Catalysts in the Hydrogenation of Imines
- 2008
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 3:8-9, s. 1390-1394
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Tidskriftsartikel (refereegranskat)abstract
- We previously reported the phosphine-free Cp*Ru(diamine)-catalyzed hydrogenation of aryl methyl ketones. Herein we present the first report of ruthenium-diamine-catalyzed imine hydrogenation to form amines. The most effective catalyst, I/KOtBu, completely converted several imines to amines at room temperature. The effect of electron-donating and -with- drawing groups on the reaction was investigated using a suitable series of substrates. The asymmetric version of the reaction was studied for two substrates, and the chiral amine products could be obtained in moderate enantiomeric excess.
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| 6. |
- Das, Suman, et al.
(författare)
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Alloying in an Intercalation Host : Metal Titanium Niobates as Anodes for Rechargeable Alkali-Ion Batteries
- 2018
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Ingår i: Chemistry - An Asian Journal. - : Wiley-VCH Verlagsgesellschaft. - 1861-4728 .- 1861-471X. ; 13:3, s. 299-310
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Tidskriftsartikel (refereegranskat)abstract
- We discuss here a unique flexible non-carbonaceous layered host, namely, metal titanium niobates (M-Ti-niobate, M: Al3+, Pb2+, Sb3+, Ba2+, Mg2+), which can synergistically store both lithium ions and sodium ions via a simultaneous intercalation and alloying mechanisms. M-Ti-niobate is formed by ion exchange of the K+ ions, which are specifically located inside galleries between the layers formed by edge and corner sharing TiO6 and NbO6 octahedral units in the sol-gel synthesized potassium titanium niobate (KTiNbO5). Drastic volume changes (approximately 300-400%) typically associated with an alloying mechanism of storage are completely tackled chemically by the unique chemical composition and structure of the M-Ti-niobates. The free space between the adjustable Ti/Nb octahedral layers easily accommodates the volume changes. Due to the presence of an optimum amount of multivalent alloying metal ions (50-75% of total K+) in the M-Ti-niobate, an efficient alloying reaction takes place directly with ions and completely eliminates any form of mechanical degradation of the electroactive particles. The M-Ti-niobate can be cycled over a wide voltage range (as low as 0.01V) and displays remarkably stable Li+ and Na+ ion cyclability (>2 Li+/Na+ per formula unit) for widely varying current densities over few hundreds to thousands of successive cycles. The simultaneous intercalation and alloying storage mechanisms is also studied within the density functional theory (DFT) framework. DFT expectedly shows a very small variation in the volume of Al-titanium niobate following lithium alloying. Moreover, the theoretical investigations also conclusively support the occurrence of the alloying process of Li ions with the Al ions along with the intercalation process during discharge. The M-Ti-niobates studied here demonstrate a paradigm shift in chemical design of electrodes and will pave the way for the development of a multitude of improved electrodes for different battery chemistries.
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| 7. |
- De Adhikari, Amrita, et al.
(författare)
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Polyaniline-Stabilized Intertwined Network-like Ferrocene/Graphene Nanoarchitecture for Supercapacitor Application
- 2017
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Ingår i: Chemistry - An Asian Journal. - : WILEY-V C H VERLAG GMBH. - 1861-4728 .- 1861-471X. ; 12:8, s. 900-909
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Tidskriftsartikel (refereegranskat)abstract
- The present work highlights the effective H-p interaction between metallocenes ( ferrocene; Fc) and graphene and their stabilization in the presence of polyaniline ( PANI) through pi-pi interactions. The PANI-stabilized Fc@ graphene nanocomposite ( FcGA) resembled an intertwined network-like morphology with high surface area and porosity, which could make it a potential candidate for energy-storage applications. The relative interactions between the components were assessed through theoretical ( DFT) calculations. The specific capacitance calculated from galvanostatic charging/discharging indicated that the PANI-stabilized ter-nary nanocomposite exhibited a maximum specific capacitance of 960 Fg(-) at an energy density of 85 WhKg(-1) and a current density of 1 Ag-. Furthermore, electrochemical impedance spectroscopy (EIS) analysis confirmed the low internal resistance of the as-prepared nanocomposites, which showed improved charge-transfer properties of graphene after incorporation of Fc and stabilization with PANI. Additionally, all electrodes were found to be stable up to 5000 cycles with a specific capacitance retention of 86%, thus demonstrating the good reversibility and durability of the electrode material.
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| 8. |
- Fan, Qunping, 1989, et al.
(författare)
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Fluorinated Photovoltaic Materials for High-Performance Organic Solar Cells
- 2019
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-471X .- 1861-4728. ; 14:18, s. 3085-3095
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Forskningsöversikt (refereegranskat)abstract
- Over the past decade, organic solar cells (OSCs) have achieved a dramatic boost in their power conversion efficiencies from about 6 % to over 16 %. In addition to developments in device engineering, innovative photovoltaic materials, especially fluorinated donors and acceptors, have become the dominant factor for improved device performance. This minireview highlights fluorinated photovoltaic materials that enable efficient OSCs. Impressive OSCs have been obtained by developing some important molds of fluorinated donor and acceptor systems. The molecular design strategy and the matching principle of fluorinated donors and acceptors in OSCs are discussed. Finally, a concise summary and outlook are presented for advances in fluorinated materials to realize the practical application of OSCs.
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| 9. |
- Fu, Yating, et al.
(författare)
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Rational Synthesis of 5,5,5-Tricyclic Fused Thia-heptaphyrin (1.1.1.1.1.1.0) From a Helical Oligopyrrin Hybrid
- 2020
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Ingår i: Chemistry - An Asian Journal. - : WILEY-V C H VERLAG GMBH. - 1861-4728 .- 1861-471X. ; 15:8, s. 1285-1289
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of a thiophene-hexapyrrane hybrid S-P-6 afforded a stable conjugated open-chain thiaheptapyrrolic helix 1 with the terminal thiophene and confused pyrrole units lying at a long distance that is adverse for further cyclization. Chelation of 1 with copper(II) ion afforded 1-Cu, which exhibits more distant terminal units. Interestingly, further oxidation of 1 triggered an intramolecular C-N fusion reaction to afford a unique 5,5,5-tricyclic fused linear thiaheptapyrrin 2, with the two terminals positioned in proximity, which favors the oxidative ring-closure reaction to give a unique 5,5,5-tricyclic fused thiaheptaphyrin (1.1.1.1.1.1.0) 3 under air. The inner-fusion strategy for positioning the reactive sites in proximity to promote oxidative cyclization offers a new approach for constructing large porphyrinoids through conjugated oligopyrrins without the assistance of metal ions.
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| 10. |
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| 11. |
- Kessler, Vadim, et al.
(författare)
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Methodical Thermolysis of [Ba2Ti2(thd)(4)(OnPr)(8)(nPrOH)(2)] under Autogenous Pressure Followed by Combustion for the Synthesis of Dielectric Tetragonal BaTiO3 Nanopowder
- 2009
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 4, s. 1084-1091
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Tidskriftsartikel (refereegranskat)abstract
- The tetragonal BaTiO3 nanopowder is synthesized in a solvent-less, efficient process by the thermolysis of a single [Ba2Ti2(thd)(4)(OnPr)(8)(nPrOH)(2)] precursor in a closed reactor at 700 degrees C under autogenous pressure, followed by combustion. This paper compiles the synthesis of the [Ba2Ti2(thd)(4)(OnPr)(8)(nPrOH)(2)] precursor, its analysis by mass spectrometry, and implementation for the fabrication of dielectric tetragonal BaTiO3 nanopowder by controlled efficient thermal decomposition. The as-prepared, intermediate, and final forms of the obtained nanomaterials are systematically analysed by XRD, Raman, and EDS measurements to gain structural and compositional information. Employing HR-SEM, TEM, and HR-TEM techniques, the morphological changes during the structural evolution of all the phases are pursued. The mechanistic elucidation for the fabrication of BaTiO3 nanopowder is developed on the basis of TGA and DTA data obtained for the initial [Ba2Ti2(thd)(4)(OnPr)(8)(nPrOH)(2)] reactant as well as the as prepared BaCO3 With amorphous Ti phase.
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| 12. |
- Khossossi, Nabil, et al.
(författare)
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Recent progress of defect chemistry on 2D materials for advanced battery anodes
- 2020
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 15:21, s. 3390-3404
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Forskningsöversikt (refereegranskat)abstract
- The rational design of anode materials plays a significant factor in harnessing energy storage. With an in-depth insight into the relationships and mechanisms that underlie the charge and discharge process of two-dimensional (2D) anode materials. The efficiency of rechargeable batteries has significantly been improved through the implementation of defect chemistry on anode materials. This mini review highlights the recent progress achieved in defect chemistry on 2D materials for advanced rechargeable battery electrodes, including vacancies, chemical functionalization, grain boundary, Stone Wales defects, holes and cracks, folding and wrinkling, layered von der Waals (vdW) heterostructure in 2D materials. The defect chemistry on 2D materials provides numerous features such as a more active adsorption sites, great adsorption energy, better ions-diffusion and therefore higher ion storage, which enhances the efficiency of the battery electrode.
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| 13. |
- Kloss, Florian, et al.
(författare)
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Metal-Free 1,5-Regioselective Azide-Alkyne [3+2]-Cycloaddition
- 2011
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 6:10, s. 2816-2824
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Tidskriftsartikel (refereegranskat)abstract
- [3+2]-cycloaddition reactions of aromatic azides and silylated alkynes in aqueous media yield 1,5-disubstituted-4-(trimethyl-silyl)-1H-1,2,3-triazoles. The formation of the 1,5-isomer is highly favored in this metal-free cycloaddition, which could be proven by 1D selective NOESY and X-ray investigations. Additionally, DFT calculations corroborate the outstanding favoritism regarding the 1,5-isomer. The described method provides a simple alternative protocol to metal-catalyzed "click chemistry" procedures, widening the scope for regioselective heavy-metal-free synthetic applications.
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| 14. |
- Li, Fei, et al.
(författare)
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Water Splitting via Decoupled Photocatalytic Water Oxidation and Electrochemical Proton Reduction Mediated by Electron-Coupled-Proton Buffer
- 2017
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Ingår i: Chemistry - An Asian Journal. - : WILEY-V C H VERLAG GMBH. - 1861-4728 .- 1861-471X. ; 12:20, s. 2666-2669
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Tidskriftsartikel (refereegranskat)abstract
- Water splitting mediated by electron-coupled-proton buffer (ECPB) provides an efficient way to avoid gas mixing by separating oxygen evolution from hydrogen evolution in space and time. Though electrochemical and photoelectrochemcial water oxidation have been incorporated in such a two-step water splitting system, alternative ways to reduce the cost and energy input for decoupling two half-reactions are desired. Herein, we show the feasibility of photocatalytic oxygen evolution in a powder system with BiVO4 as a photocatalyst and polyoxometalate H3PMo12O40 as an electron and proton acceptor. The resulting reaction mixture was allowed to be directly used for the subsequent hydrogen evolution with the reduced H3PMo12O40 as electron and proton donors. Our system exhibits excellent stability in repeated oxygen and hydrogen evolution, which brings considerable convenience to decoupled water splitting.
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| 15. |
- Li, Zhong-Yu, et al.
(författare)
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Restricted Rotation of sigma-Bonds through a Rigidified Donor Structure to Increase the ICT Ability of Platinum-Acetylide-Based DSSCs
- 2013
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 8:11, s. 2660-2669
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Tidskriftsartikel (refereegranskat)abstract
- A series of new triarylamine-based platinum-acetylide complexes (WYs) have been designed and synthesized as new sensitizers for applications in dye-sensitized solar cells (DSSCs). With the aim of investigating the effect of a rigidifying donor structure on the photoelectrical parameters of the corresponding DSSCs, two new sensitizers, WY1 and WY2, with rigid and coplanar fluorene units as an electron donor, were prepared. Moreover, two sensitizers that contained triphenylamine units as an electron donor, WY3 and WY4, were also synthesized for comparison. The photo- and electrochemical properties of all of these new complexes have been extensively explored. We found that the dimethyl-fluorene unit exhibited a stronger electron-donating ability and better photovoltaic performance compared to the triphenylamine unit, owing to its rigidifying structure, which restricted the rotation of sigma bonds, thus increasing the conjugation efficiency. Furthermore, WY2, which contained a dimethyl-fluorene unit as an electron donor and bithiophene as a bridge, showed a relatively high open-circuit voltage (V-oc) of 640mV and a PCE of 4.09%. This work has not only expanded the choice of platinum-acetylide sensitizers, but also demonstrates the advantages of restricted rotation of donor sigma bonds for improved behavior of the corresponding DSSCs.
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| 16. |
- Liu, Tianqi, et al.
(författare)
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Iron-Based Molecular Water Oxidation Catalysts : Abundant, Cheap, and Promising
- 2019
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Ingår i: Chemistry - An Asian Journal. - : WILEY-V C H VERLAG GMBH. - 1861-4728 .- 1861-471X. ; 14:1, s. 31-43
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Forskningsöversikt (refereegranskat)abstract
- An efficient and robust water oxidation catalyst based on abundant and cheap materials is the key to converting solar energy into fuels through artificial photosynthesis for the future of humans. The development of molecular water oxidation catalysts (MWOCs) is a smart way to achieve promising catalytic activity, thanks to the clear structures and catalytic mechanisms of molecular catalysts. Efficient MWOCs based on noble-metal complexes, for example, ruthenium and iridium, have been well developed over the last 30 years; however, the development of earth-abundant metal-based MWOCs is very limited and still challenging. Herein, the promising prospect of iron-based MWOCs is highlighted, with a comprehensive summary of previously reported studies and future research focus in this area.
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| 17. |
- Ma, Ming-Guo, et al.
(författare)
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The Microwave-Assisted Ionic-Liquid Method : A Promising Methodology in Nanomaterials
- 2014
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 9:9, s. 2378-2391
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Forskningsöversikt (refereegranskat)abstract
- In recent years, the microwave-assisted ionic-liquid method has been accepted as a promising methodology for the preparation of nanomaterials and cellulose-based nanocomposites. Applications of this method in the preparation of cellulose-based nanocomposites comply with the major principles of green chemistry, that is, they use an environmentally friendly method in environmentally preferable solvents to make use of renewable materials. This minireview focuses on the recent development of the synthesis of nanomaterials and cellulose-based nanocomposites by means of the microwave-assisted ionic-liquid method. We first discuss the preparation of nanomaterials including noble metals, metal oxides, complex metal oxides, metal sulfides, and other nanomaterials by means of this method. Then we provide an overview of the synthesis of cellulose-based nanocomposites by using this method. The emphasis is on the synthesis, microstructure, and properties of nanostructured materials obtained through this methodology. Our recent research on nanomaterials and cellulose- based nanocomposites by this rapid method is summarized. In addition, the formation mechanisms involved in the microwave-assisted ionic-liquid synthesis of nanostructured materials are discussed briefly. Finally, the future perspectives of this methodology in the synthesis of nanostructured materials are proposed.
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| 18. |
- Mondal, I. C., et al.
(författare)
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Organosulfur/Selenium-Based Highly Fluorogenic Molecular Probes for Live-Cell Nucleolus Imaging
- 2022
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 17:7
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Tidskriftsartikel (refereegranskat)abstract
- We present fluorogenic cationic organo chalcogens that are highly selective to RNA. We have demonstrated that the conformational dynamics and subsequently the optical properties of these dyes can be controlled to facilitate efficient bioimaging. We report the application of organoselenium and organosulfur-based cell-permeable red-emissive probes bearing a favorable cyclic sidearm for selective and high contrast imaging of cell nucleoli. The probes exhibit high quantum yield upon interacting with RNA in an aqueous solution. An in-depth multiscale simulation study reveals that the prominent rotational freezing of the electron-donating sidearm of the probes in the microenvironment of RNA helps in attaining more planar conformation when compared to DNA. It exerts a greater extent of intramolecular charge transfer and hence leads to enhanced fluorescence emission. A systematic structure-interaction relationship study highlighted the impact of heavy-chalcogens toward the improved emissive properties of the probes.
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| 19. |
- Ohlin, C. Andre
(författare)
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Reaction Dynamics and Solution Chemistry of Polyoxometalates by Electrospray Ionization Mass Spectrometry
- 2012
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 7:2, s. 262-270
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Tidskriftsartikel (refereegranskat)abstract
- Mass spectrometry both complements other analytical techniques and allows for types of analyses and experiments not possible with common analytical methods, such as NMR, IR, and UV/Vis spectroscopy. Electrospray constitutes one of the mildest forms of ionization, making it the preferred method for the analysis of large fragile or reactive ions. There is particular promise for mass spectrometry in aiding the characterization of polyoxometalates and their solutions, but caution must be taken in designing the experiments in order to yield reliable data and to avoid the temptation of over-interpreting the relevance of gas-phase data to solution chemistry.
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| 20. |
- Ren, Bo, et al.
(författare)
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A Carbohydrate- Anion Recognition System in Aprotic Solvents
- 2014
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 9:5, s. 1298-1304
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Tidskriftsartikel (refereegranskat)abstract
- A carbohydrate-anion recognition system in nonpolar solvents is reported, in which complexes form at the B-faces of -D-pyranosides with H1-, H3-, and H5-cis patterns similar to carbohydrate- interactions. The complexation effect was evaluated for a range of carbohydrate structures; it resulted in either 1:1 carbohydrate-anion complexes, or 1:2 complex formation depending on the protection pattern of the carbohydrate. The interaction was also evaluated with different anions and solvents. In both cases it resulted in significant binding differences. The results indicate that complexation originates from van der Waals interactions or weak CHA(-) hydrogen bonds between the binding partners and is related to electron-withdrawing groups of the carbohydrates as well as increased hydrogen-bond-accepting capability of the anions.
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| 21. |
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| 22. |
- Wu, ZhiFang, et al.
(författare)
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Influence of the Auxiliary Acceptor on the Absorption Response and Photovoltaic Performance of Dye-Sensitized Solar Cells
- 2014
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 9:12, s. 3549-3557
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Tidskriftsartikel (refereegranskat)abstract
- Three new dyes with a 2-(1,1-dicyanomethylene)rhodanine (IDR-I, -II, -III) electron acceptor as anchor were synthesized and applied to dye-sensitized solar cells. We varied the bridging molecule to fine tune the electronic and optical properties of the dyes. It was demonstrated that incorporation of auxiliary acceptors effectively increased the molar extinction coefficient and extended the absorption spectra to the near-infrared (NIR) region. Introduction of 2,1,3-benzothiadiazole (BTD) improved the performance by nearly 50%. The best performance of the dye-sensitized solar cells (DSSCs) based on IDR-II reached 8.53% (short-circuit current density (J(sc))=16.73mAcm(-2), open-circuit voltage (V-oc)=0.71V, fill factor (FF)=71.26%) at AM1.5 simulated sunlight. However, substitution of BTD with a group that featured the more strongly electron-withdrawing thiadiazolo[3,4-c]pyridine (PT) had a negative effect on the photovoltaic performance, in which IDR-III-based DSSCs showed the lowest efficiency of 4.02%. We speculate that the stronger auxiliary acceptor acts as an electron trap, which might result in fast combination or hamper the electron transfer from donor to acceptor. This inference was confirmed by electrical impedance analysis and theoretical computations. Theoretical analysis indicates that the LUMO of IDR-III is mainly localized at the central acceptor group owing to its strong electron-withdrawing character, which might in turn trap the electron or hamper the electron transfer from donor to acceptor, thereby finally decreasing the efficiency of electron injection into a TiO2 semiconductor. This result inspired us to select moderated auxiliary acceptors to improve the performance in our further study.
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| 23. |
- Xie, Sheng, et al.
(författare)
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Impact of Hydrogen Bonding on the Fluorescence of N-Amidinated Fluoroquinolones
- 2019
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Ingår i: Chemistry - An Asian Journal. - : Wiley-Blackwell. - 1861-4728 .- 1861-471X. ; 14:6, s. 910-916
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Tidskriftsartikel (refereegranskat)abstract
- The fluorescence properties of AIE-active N-amidinated fluoroquinolones, efficiently obtained by a perfluoroaryl azide-aldehyde-amine reaction, have been studied. The fluorophores were discovered to elicit a highly sensitive fluorescence quenching response towards guest molecules with hydrogen-bond-donating ability. This effect was evaluated in a range of protic/aprotic solvents with different H-bonding capabilities, and also in aqueous media. The influence of acid/base was furthermore addressed. The hydrogen-bonding interactions were studied by IR, NMR, UV/Vis and time-resolved fluorescence decay, revealing their roles in quenching of the fluorescence emission. Due to the pronounced quenching property of water, the N-amidinated fluoroquinolones could be utilized as fluorescent probes for quantifying trace amount of water in organic solvents.
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| 24. |
- Yadav, Sangeeta, et al.
(författare)
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Exploiting the Aromatic Chameleon Character of Fulvenes for Computational Design of Baird-Aromatic Triplet Ground State Compounds
- 2019
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Ingår i: Chemistry - An Asian Journal. - : Wiley-VCH Verlagsgesellschaft. - 1861-4728 .- 1861-471X. ; 14:10, s. 1870-1878
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Tidskriftsartikel (refereegranskat)abstract
- Due to the reversal in electron counts for aromaticity and antiaromaticity in the closed-shell singlet state (normally ground state, S-0) and lowest * triplet state (T-1 or T-0), as given by Huckel's and Baird's rules, respectively, fulvenes are influenced by their substituents in the opposite manner in the T-1 and S-0 states. This effect is caused by a reversal in the dipole moment when going from S-0 to T-1 as fulvenes adapt to the difference in electron counts for aromaticity in various states; they are aromatic chameleons. Thus, a substituent pattern that enhances (reduces) fulvene aromaticity in S-0 reduces (enhances) aromaticity in T-1, allowing for rationalizations of the triplet state energies (E-T) of substituted fulvenes. Through quantum chemical calculations, we now assess which substituents and which positions on the pentafulvene core are the most powerful for designing compounds with low or inverted E-T. As a means to increase the -electron withdrawing capacity of cyano groups, we found that protonation at the cyano N atoms of 6,6-dicyanopentafulvenes can be a route to on-demand formation of a fulvenium dication with a triplet ground state (T-0). The five-membered ring of this species is markedly Baird-aromatic, although less than the cyclopentadienyl cation known to have a Baird-aromatic T-0 state.
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| 25. |
- Zhang, Biaobiao, et al.
(författare)
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Homogeneous Oxidation of Water by Iron Complexes with Macrocyclic Ligands
- 2014
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728 .- 1861-471X. ; 9:6, s. 1515-1518
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Tidskriftsartikel (refereegranskat)abstract
- The activity of eleven separated iron complexes and nine in situ-generated iron complexes towards catalytic water oxidation have been examined in aqueous solutions with Ce(NH4)(2)(NO3)(6) as the oxidant. Two iron complexes bearing tridentate and tetradentate macrocyclic ligands were found to be novel water oxidation catalysts. The one with tetradentate ligand exhibited a promising activity with a turnover number of 65 for oxygen evolution.
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| 26. |
- Zhang, B., et al.
(författare)
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In Situ Formation of Efficient Cobalt-Based Water Oxidation Catalysts from Co2+-Containing Tungstate and Molybdate Solutions
- 2015
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X. ; 10:10, s. 2228-2233
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Tidskriftsartikel (refereegranskat)abstract
- Replacing rare and expensive noble-metal catalysts with inexpensive and earth-abundant ones is of great importance to split water either electrochemically or photoelectrochemically. In this study, two amorphous cobalt oxide catalysts (Co-W film and Co-Mo film) with high activity for electrocatalytic water oxidation were prepared by fast, simple electrodeposition from aqueous solutions of Na2WO4 and Na2MoO4 containing Co2+. In solutions of Na2WO4 and Na2MoO4, sustained anodic current densities up to 1.45 and 0.95mA cm-2 were obtained for Co-W film at 1.87V versus a reversible hydrogen electrode (RHE) and Co-Mo film on fluorine-doped tin oxide (FTO) substrates at 1.85V versus RHE. For the Co-W film, a much higher current density of 4.5mA cm-2 was acquired by using a stainless-steel mesh as the electrode substrate. Significantly, in long-term electrolysis for 13h, the Co-W film exhibited improved stability in cobalt-free buffer solution in comparison with the previously reported Co-Pi film.
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| 27. |
- Zhang, Haitao, et al.
(författare)
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Gel Electrolytes: Chemistry and Applications
- 2023
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X. ; 18:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 28. |
- Zhang, Zhicheng, et al.
(författare)
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The Editorial
- 2023
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Ingår i: Chemistry - An Asian Journal. - : John Wiley & Sons. - 1861-4728 .- 1861-471X. ; 18:6
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Surface and interface engineering has been considered as a promising strategy to enhance the performance of catalysts towards CO2 reduction. In their editorial to this special collection, guest editors Zhicheng Zhang, Zhen Zhang, Zhenyu Sun, Shaoqi Zhan and Guoxiong Wang provide a brief overview of this field and highlight the state-of-the-art contributions featured in this special collection.
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| 29. |
- Dong, Bin, et al.
(författare)
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Local and Remote Charge-Transfer-Enhanced Raman Scattering on One-Dimensional Transition-Metal Oxides
- 2010
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Ingår i: Chemistry - An Asian Journal. - : Wiley. - 1861-4728. ; 5:8, s. 1824-1829
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Tidskriftsartikel (refereegranskat)abstract
- The one-dimensional (1D) transition-metal oxide MoO3 belt is synthesized and characterized with Xray diffraction, scanning electron microscopy, and Raman spectroscopy. Charge-transfer-(CT) enhanced Raman scattering of 4-mercaptobenzoic acid (4-MBA) on a 1D MoO3 belt was investigated experimentally and theoretically. The chemical enhancement of surface-enhanced Raman scattering (SERS) of 4-MBA on the MoO3 belt by CT is in the order of 10(3). The SERS of 4-MBA was investigated theoretically by using a quantum chemical method. The remote SERS of 4-MBA along the 1D MoO3 belt (the light excitation to one side of the MoO3 belt, and the SERS spectrum is collected on the other side of the MoO3 belt) is also shown experimentally, which provides potential applications of SERS. The incident polarization dependence of remote SERS spectra has also been investigated experimentally.
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