ABSTRACT
Bipolar redox organic compounds have been considered as potential next-generation electrode materials due to their sustainability, low cost and tunable structure. However, their development is still limited by the poor cycling stability and low energy density ascribed to high dissolution during cycling and the low conductivity of organic molecules. Herein, porphyrin-based bipolar organics of [5,10,15,20-tetrathienylporphinato]â MII (M=2 H, Cu (CuTTP)) are proposed as new stable organic electrodes. Enhanced cycling stability is obtained by a temperature-induced inâ situ polymerization strategy of porphyrin molecules. The resulting polymer exhibits excellent cycling stability up to 10 00â cycles even at a high current density (1000â mA g-1 ) in organic lithium-/sodium-based charge storage devices at 50 °C. In a symmetrical cell using CuTTP as both cathode and anode material a discharge capacity of 72â mAh g-1 is achieved after 600â cycles at 1000â mA g-1 . This strategy would offer a new approach to developing stable energy storage bipolar materials in organic-based devices at high temperature.
ABSTRACT
A rhodamine spirolactam derivative (1) is developed as a colormetric and fluorescent probe for trivalent aluminum ions (Al(3+)). It exhibits a highly sensitive "turn-on" fluorescent response toward Al(3+) with a 70-fold fluorescence intensity enhancement under 2 equiv. of Al(3+) added. The probe can be applied to the quantification of Al(3+) with a linear range covering from 5.0 × 10(-7) to 2.0 × 10(-5) M and a detection limit of 4.0 × 10(-8) M. Most importantly, the fluorescence changes of the probe are remarkably specific for Al(3+) in the presence of other metal ions, which meet the selective requirements for practical application. Moreover, the experiment results show that the response behavior of 1 towards Al(3+) is pH independent in neutral condition (pH 6.0-8.0) and the response of the probe is fast (response time less than 3 min). In addition, the proposed probe has been used to detect Al(3+) in water samples and image Al(3+) in living cells with satisfying results.
Subject(s)
Aluminum/analysis , Fluorescent Dyes/chemistry , Fresh Water/analysis , Optical Imaging/methods , Rhodamines/chemistry , Spectrometry, Fluorescence/methods , Cations/analysis , Fluorescence , HeLa Cells , Humans , Limit of Detection , Microscopy, Fluorescence/methodsABSTRACT
Palladium-catalyzed C-S bond formation via dehydrative-dehydrogenative double C-H sulfuration using sulfur powder is described. The dehydrogenated intermediates of cyclohexanones can be trapped to act as efficient aryl sources under an oxygen atmosphere. This procedure provides a novel approach for the preparation of benzothieno[2,3-b]indoles.
Subject(s)
Cyclohexanones/chemistry , Indoles/chemistry , Palladium/chemistry , Sulfur/chemistry , Catalysis , Crystallography, X-Ray , Molecular StructureABSTRACT
A novel palladium catalyzed approach to 3-arylindoles was developed from indoles and cyclohexanones. Various cyclohexanones acted as aryl sources via an alkylation and dehydrogenation sequence using molecular oxygen as the hydrogen acceptor. This method showed good regioselectivity and afforded 3-arylindoles as the sole products.
Subject(s)
Cyclohexanones/chemistry , Heterocyclic Compounds, 3-Ring/chemical synthesis , Indoles/chemistry , Indoles/chemical synthesis , Palladium/chemistry , Catalysis , Combinatorial Chemistry Techniques , Heterocyclic Compounds, 3-Ring/chemistry , Molecular StructureABSTRACT
2-Aryl benzothiazole formation from aryl ketones and 2-aminobenzenethiols under metal- and I(2)-free conditions was described. Various 2-aryl benzothiazoles were selectively obtained in good yields using molecular oxygen as oxidant. DMSO played an important role in this transformation. Functional groups such as methyl, methoxy, fluoro, chloro, bromo and nitro groups were tolerated under the optimized reaction conditions.
Subject(s)
Benzothiazoles/chemical synthesis , Ketones/chemistry , Sulfanilic Acids/chemistry , Benzothiazoles/chemistry , Catalysis , Combinatorial Chemistry Techniques , Dimethyl Sulfoxide , Molecular StructureABSTRACT
Two series of heteroleptic cyclometalated platinum(II) complexes [(C(n)Oppy)Pt(acac) and (C(n)OFppy)Pt(acac)] have been prepared. Their liquid-crystal and optophysical properties were studied, in which C(n)Oppy is 2-(4-alkoxyphenyl)-5-(alkoxymethyl)pyridine and C(n)OFppy is 2-(3-fluoro-4-alkoxyphenyl)-5-(alkoxymethyl)pyridine. Only the heteroleptic cyclometalated platinum(II) complexes (n = 12 and 16) exhibited enantiotropic mesophase transitions with smectic (S(m)) structure. Intense polarized luminescence with a maximum peak at 532 nm and a polarization ratio as high as 10.5 were obtained in an aligned polyimide film under opto-excitation at room temperature. This research work provides a simple approach to realize high-efficiency polarized emission by heteroleptic cyclometalated platinum(II) complexes.