The title compound, [NaLaMo8O26(C3H7NO)7]n, contains infinite chains of [Mo8O26]4− units supporting dimethylformamide‐coordinated LaIII cations and linked by Na+ cations. The lanthanum center adopts a nine‐coordinate geometry and the Na atom is sandwiched between two β‐[Mo8O26]4− units. 相似文献
A novel series of soluble and heat-resistant copoly(arylene ether phenyl-s-triazine)s (PAEPs) have been prepared for their potent utilities as structural coatings, high-temperature membranes or adhesives. The copolymers have been synthesized via the nucleophilic displacement polymerization of 2,4-bis(4-fluorophenyl)-6-phenyl-1,3,5-triazine (BFPT) with various ratios of hydroquinone (HQ) and resorcinol (RS). A key feature of these copolymers is the incorporation of multiply meta-ether linkages in the polymer chain, which results in an improvement in the solubility of poly(arylene ether phenyl-s-triazine)s in common organic solvents (e.g., N,N’-dimethylacetamide, N,N’-dimethylformamide, N-methyl-2-pyrrolidinone). The new random copolymers exhibit high glass transitions exceeding 241 °C and excellent thermal and thermo-oxidative stabilities associating with decomposition temperatures for 5% mass-loss in excess of 531 °C. These copolymers can be easily cast into tough, clear and creasable films and exhibit good mechanical properties. All copolymers are amorphous except PAEP9010 as evidenced by WAXD. Their solubility increases with an increase in meta-ether linkage content in the polymer backbone, while the crystallinity and the overall thermal stability appear to decrease slightly. This kind of phenyl-s-triazine-based poly(arylene ether) copolymers may be considered a good candidate for using as high-performance polymeric materials. 相似文献
Double the fun! Singlet–triplet dual emission at ambient temperature has been achieved in compounds containing a triarylboron acceptor and an N‐(2′‐pyridyl)‐7‐azaindolyl donor group bridged by a tetrahedral Si linker (see figure). PtII chelation and chelate‐mode switching from N,N to N,C have been found to greatly enhance phosphorescent emission. Furthermore, both singlet and triplet emission bands are responsive to fluoride ions.
Poly(trimethylene terephthalate)(PTT) is an excellent fiber material.Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis(TGA),thermogravimetric analysis-Fourier transform infrared spectroscopy(TGA-FTIR) analysis,differential scanning calorimetry(DSC) and X-ray diffraction(XRD).The thermal degradation mechanism of PTT follows Mclafferty rearrangement principle.The PTTwithintrinsicviscosity(Ⅳ) of 0.74 dL/g has a maximum crystallinity... 相似文献
An immunosensor has been fabricated for direct amperometric determination of carcinoembryonic antigen. It is based on a biocompatible composite film composed of porous chitosan (pChit) and gold nanoparticles (GNPs). Firstly, a pChit film was formed on a glassy carbon electrode by means of electrodeposition. Then, thionine as a redox probe was immobilized on the pChit film modified electrode using glutaraldehyde as a cross-linker. Finally, GNPs were adsorbed on the electrode surface to assemble carcinoembryonic antibody (anti-CEA). The surface morphology of the pChit films was studied by means of a scanning electron microscope. The immunosensor was further characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical behaviors and factors influencing the performance of the resulting immunosensors were studied in detail. Results showed that the pChit films can enhance the surface coverage of antibodies and improve the sensitivity of the immunosensor. Under optimal conditions, the immunosensor was highly sensitive to CEA with a detection limit of 0.08 ng·mL?1 at three times the background noise and linear ranges of 0.2~10.0 ng·mL?1 and 10.0~160 ng·mL?1. Moreover, the immunosensor exhibited high selectivity, good reproducibility and stability. 相似文献