Co-reporter:Ruyu Li;Yanjiao Mo;Rong Shi;Peng Li
Monatshefte für Chemie - Chemical Monthly 2014 Volume 145( Issue 1) pp:85-90
Publication Date(Web):2014 January
DOI:10.1007/s00706-013-1051-2
In order to improve efficiency, processability, and stability, two groups of novel poly(p-phenylene vinylene) (PPV) derivatives (P1–P3 and P4–P6) with hyperbranched structure and containing a nitro substituent were synthesized via a Gilch reaction in different monomer ratios. The properties of the polymers were investigated by using UV–Vis absorption, fluorescence spectroscopy, cyclic voltammetry, and thermogravimetric analysis. The result shows that the band gaps of the PPV derivatives with a nitro substituent were decreased and the polymers had higher molecular weights (106), excellent solubility in common organic solvents, good film-forming ability, and better thermal stability. The polymers can be used as an efficient acceptor material in polymeric solar cells.
Co-reporter:Wei-Jie Li, Bin Liu, Yan Qian, Ling-Hai Xie, Jing Wang, Sheng-Biao Li and Wei Huang
Polymer Chemistry 2013 vol. 4(Issue 6) pp:1796-1802
Publication Date(Web):11 Dec 2012
DOI:10.1039/C2PY20971C
Diazafluorene (DAF) has a similar configuration to a fluorene unit except that two carbon atoms are replaced with nitrogen atoms, offering an ideal model of supramolecular conjugated polymers to investigate the structure–property relationship. Herein, a series of DAF-based oligofluorenes and polyfluorenes, including NFF, NF2F, F2NF, PFO-NO, PFO-N5, PFO-N15 and PFO-N50, have been synthesized by Suzuki and/or Yamamoto polymerization. All dioctyldiazafluorene-based copolymers show improved solubility, high quantum efficiency and good thermal stability. The 4,5-diazafluorenone (DAFone)-based oligomers exhibit solvent-dependent fluorescence and DAF-based copolymers show an optical response with a large red-shift (ca. 40–60 nm) of the absorption peak when they were protonated with trifluoroacetic acid. Their photoluminescent properties have also been obviously tuned by coordinating different metal ions to the polymers. DAF-based conjugated polymers are potential supramolecular polymer semiconductors for thin film electronics.
Co-reporter:Hao Zheng, Chuanqi Feng, Seung-Joo Kim, Shengyu Yin, Huimin Wu, Shiquan Wang, Shengbiao Li
Electrochimica Acta 2013 Volume 88() pp:225-230
Publication Date(Web):15 January 2013
DOI:10.1016/j.electacta.2012.09.119
KMn8O16 nanorods were prepared for the first time by a rheological phase reaction method, using KMnO4 and Mn(CH3COO)2·4H2O as reactants. The KMn8O16 samples annealed at different temperatures were characterized by X-ray diffraction, transmission electron microscopy, and galvanostatic charge/discharge profile measurement. The KMn8O16 nanorods annealed at 400 °C show the highest reversible discharge capacity (153.8 mAh/g even after 50 cycles) at current density of 50 mA/g and the best cycling stability. The annealed nanorods exhibit the superior electrochemical performances compared to the unannealed sample, which is confirmed by the AC impedance measurements. These results indicate that the KMn8O16 nanorods could be a promising cathode material for lithium ion batteries.Graphical abstractHighlights► KMn8O16 nanorods were prepared for the first time by a rheological phase method. ► The nanorods have a diameter of about 5–15 nm and a length of around 50–300 nm. ► The annealed nanorods exhibit the better electrochemical properties and cyclability. ► The sample annealed at 400 °C show high capacity of 153.8 mAh/g at the 50th cycle.
Co-reporter:Yan Tang;Hui-Ran Yang;Hui-Bin Sun; Shu-Juan Liu;Jing-Xia Wang; Qiang Zhao;Dr. Xiang-Mei Liu;Dr. Wen-Juan Xu; Sheng-Biao Li; Wei Huang
Chemistry - A European Journal 2013 Volume 19( Issue 4) pp:1311-1319
Publication Date(Web):
DOI:10.1002/chem.201203137
Abstract
Biothiols, such as cysteine (Cys) and homocysteine (Hcy), play very crucial roles in biological systems. Abnormal levels of these biothiols are often associated with many types of diseases. Therefore, the detection of Cys (or Hcy) is of great importance. In this work, we have synthesized an excellent “OFF-ON” phosphorescent chemodosimeter 1 for sensing Cys and Hcy with high selectivity and naked-eye detection based on an IrIII complex containing a 2,4-dinitrobenzenesulfonyl (DNBS) group within its ligand. The “OFF-ON” phosphorescent response can be assigned to the electron-transfer process from IrIII center and C^N ligands to the DNBS group as the strong electron-acceptor, which can quench the phosphorescence of probe 1 completely. The DNBS group can be cleaved by thiols of Cys or Hcy, and both the 3MLCT and 3LC states are responsible for the excited-state properties of the reaction product of probe 1 and Cys (or Hcy). Thus, the phosphorescence is switched on. Based on these results, a general principle for designing “OFF-ON” phosphorescent chemodosimeters based on heavy-metal complexes has been provided. Importantly, utilizing the long emission-lifetime of phosphorescence signal, the time-resolved luminescent assay of 1 in sensing Cys was realized successfully, which can eliminate the interference from the short-lived background fluorescence and improve the signal-to-noise ratio. As far as we know, this is the first report about the time-resolved luminescent detection of biothiols. Finally, probe 1 has been used successfully for bioimaging the changes of Cys/Hcy concentration in living cells.
.jpg)
