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101.
合成了九种不同摩尔比的苯基苯甲酰甲基亚砜高氯酸镝、铥异核配合物,通过元素分析、稀土滴定确定其组成为(DyxTmy)L5(ClO4)3·2H2O(x∶y=1.000∶0.000,0.999∶0.001,0.995∶0.005,0.990∶0.010,0.900∶0.100,0.800∶0.200,0.700∶0.300,0.600∶0.400,0.500∶0.500,L=C6H5SOCH2COC6H5).红外光谱及摩尔电导表明,配体通过亚砜基上的氧原子与稀土离子配位,羰基氧不参与配位,三个ClO4-均在外界不参与配位.荧光光谱表明:当Tm3 的掺入量在0.001~0.300 mol之间时,对Dy3 的荧光有极强的敏化作用,且当Tm3 的掺入量为0.010 mol时,敏化强度最大,可使Dy3 荧光强度增加246%. 相似文献
102.
103.
Acyclic olefinic amides were iodolactonized in the mixed solvent of CH3CN and H2O (90:102 v/v) under reflux to give products with trans configuration of the newly formed iodomethyl to the inherent alkyl group in high yield. 相似文献
104.
A solid-supported acidic oxazolium perchlorate was investigated as a heterogeneous catalyst in N-glycosylation reactions using silylated modified pyrimidines and an acylated ribose or glucose to afford the corresponding pyrimidine nucleosides. This salt is a nonhygroscopic and stable powder whose activity is comparable to that of 2-methyl-5-phenylbenzoxazolium perchlorate. A reaction with this polymer catalyst can be conducted on a gram scale. Reusability of the solid-supported catalyst was also investigated. 相似文献
105.
A pilot plant study of the radiation grafting of styrene to polyvinyl chloride) (PVC) latex is described. When correct extraction conditions are used less than 3% grafting took place. This is shown to be due to the low total radiation doses needed to polymerize the styrene in an emulsion system. A parallel study with PVC film did, however, lead to substantial true grafting. The G (radical) value for PVC film as determined by ESR was found to be 4.6. 相似文献
106.
Larisa Petrovna Demyanova Viaseslav S. Rimkevich Alexandre S. Buynovskiy 《Journal of fluorine chemistry》2011,132(12):1067-1071
A method of elaboration of nanometric amorphous silica is proposed using a rational processing of quartz-based ores with the help of a fluorination method. The different steps of the process are described, including the kinetics of the interaction mechanism of ammonium bifluoride with the initial raw materials, the sublimation of ammonium fluorosilicate and the formation of nanometric amorphous silica. Rate constants and activation energy of the chemical reactions are calculated. 相似文献
107.
Birczyński A Lalowicz ZT Olejniczak Z Stoch G Petelenz B 《Solid state nuclear magnetic resonance》2005,28(2-4):142-159
Partially deuterated ammonium compounds contain ammonium ion isotopomers with relative abundances given by the binomial distribution of protons and deuterons. All isotopomers with deuterons contribute characteristic deuteron NMR spectra at 5K. Experimental NMR spectra were separated and respective contributions of isotopomers were determined. The derived contributions agree with expected values for a given deuteration in the case of ammonium hexafluorophosphate. In ammonium hexachlorotellurate both NH2D2+ and about 50% of NH3D+ ions are rigid, while the remaining NH3D+ perform limited jumps. NHD3+ and ND4+ ions undergo tunnelling rotation, NH3D+ ions perform either jumps about C2 axis or limited jumps, but some stay rigid in ammonium hexachlorostannate. NH2D2+, NHD 3+ and ND4+ undergo rotational tunnelling. In the case of ammonium perchlorate, the NH3D+ ions perform either jumps about C3 axis or limited jumps whilst some remain rigid. Very low values of activation energies were derived for all spectral components from the temperature dependence of their spectra, up to about 20K, which indicates an incoherent tunnelling nature of the observed dynamic processes. The diverse mobility of NH3D+ ions appears to be the most interesting and new feature. 相似文献
108.
109.
110.
Controllable synthesis and characterization of ammonium polyphosphate with crystalline form V by phosphoric acid process 总被引:2,自引:0,他引:2
Gousheng Liu Wenyan Chen Xinchun Liu Jianguo Yu 《Polymer Degradation and Stability》2010,95(9):1834-12155
Ammonium polyphosphate (APP) with crystalline form V (APP-V) was synthesized by heating a mixture of 85% food-grade phosphoric acid and melamine under dry ammonia atmosphere. Effects such as raw material ratios, charging methods, dehydration temperature, condensation temperature and condensation time were investigated. Its water solubility was tested, its XRD and FTIR were characterized and compared with those of industrial APP-I and APP-II. Results showed that the prepared APP-V was insoluble in water, its XRD spectrum was the same as APP-V in literature. The molecular structures of the prepared APP-V and APP-I/APP-II were speculated and discussed in detail. 相似文献