裂解色谱法测定环化顺1,4聚丁二烯的环化度

用裂解色谱法(PGC)研究了不同环化度的环化顺1,4聚丁二烯(CPBd)。建立了测定CPBd环化度的方法。分析了不同实验条件下生成的CPBd的环化度,结果与NMR测定值一致。

二(2,4,4-三甲基戊基)膦酸萃取分离稀土元素(Ⅲ)的研究

本文研究了二(2,4,4-三甲基戊基)磷酸(Cyanex 272)的煤油溶液在不同介质(HCI,HNO_3)中对三价混合稀土的萃取分离性能.观测了平衡水相酸度对萃取平衡的影响,由酸度曲线求出相邻元素的平均分离系数,并考察了酸度对反萃取平衡的影响.比较了HCI和HNO_3介质中,Cyanex 272对混合稀土(Ⅲ)的萃取性能.

异丙基磷酸单(1-已基-4-乙基)辛酯萃取分离锆、钍、钛、铁、镥及其机理

本文通过异丙基膦酸单(1-己基-4-乙基)辛酯在硫酸介质中对Zr~(4+)、Th~(4+)、Ti~(4+)、Fe~(3+)、Lu~(3-)的萃取平衡研究,探讨了Zr~(4-)与其它离子分离的可能性,提出了萃取Zr~(4-)的三种反应机理,并计算了萃取反应平衡常数和热力学函数.

铕和铽与3,4-呋喃二甲酸双核配合物的合成、表征及其晶体结构

本文首次合成了铕(Ⅲ)和铽(Ⅲ)与3,4-呋喃二甲酸配合物,研究了它们的IR、DTA、TG、DTG和荧光光谱等性质,并完成了单晶的晶体分析。结果表明,配合物为〔Ln·HL_2(H_2O)_2〕_2·2H_2O(Ln=Eu(Ⅲ),Tb(Ⅲ);H_2L=3,4-呋喃二甲酸),属单斜晶系,P2/c空间群,Z=2,晶胞参数对铕和铽配合物分别为α=10.842(1),10.801(4);b=8.725(2),8.664(2);c=16.366(4),16.308(6)A;β=93.50(1),93.67(3)°;V=1545.3(5),1523.0(8)A~3。

Crystal structure and DFT studies of a triazole derivative: 4-(2-hydrobenzylideneamino)-3-(1,2,4-triazol-4-yl-methyl) 1H-1,2,4-triazole-5 (4H)-thione

A novel triazole derivative 4-(2-hydrobenzylideneamino)-3-(1, 2, 4-triazol-4-ylmethyl)-1H-1, 2, 4-triazole-5 (4H)-thione(1) was synthesized and characterized using elemental analysis, MR, and H-1 NMR, and its crystal structure was determined via X-ray single crystal diffraction analysis. Crystal data: monoclinic, P2 (1)/c, a = 0.83335 (9) nm, b = 1. 49777 (16) run, c = 1. 14724 (12) nm, beta = 107. 990 (2)degrees, D = 1. 470 Mg/m(3), and Z = 4. The geometries and the vibrational frequencies were determined using the density functional theory(DFT) method at the B3LYP/6-31G* level. To demonstrate the accuracy of the reaction route of compound 1, one of the important intermediates was also tested using the same method. The structural parameters of the two compounds calculated using the DFT study are close to those of the crystals, and the harmonic vibrations of the two compounds computed via the DFT method are in good agreement with those in the observed IR spectral data. The thermodynamic properties of the title compound were calculated, and the compound shows a good structural stability at normal temperature. The test results of biological activities show that it has a certain bactericidal ability.

Pre-column derivatization of amines with 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl chloroformate followed by LC-fluorescence and LC-APCI-MS

A pre-column derivatization method for the sensitive determination of amines using the labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl chloroformate (BCIC-Cl) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives is carried out by high performance liquid chromatography/atmospheric pressure chemical ionization (LC-APCl-MS-MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent is replaced by 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl functional group, which results in a sensitive fluorescence derivatizing reagent BCIC-Cl. BCIC-Cl can easily and quickly label amines. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography and show an intense protonated molecular ion corresponding m/z [MH](+) under APCl in positive-ion mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 260 corresponding to the cleavage of CH2-OCO bond. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3 to 4-fold molar reagent excess. In addition, the detection responses for BCIC derivatives are compared with those obtained using CEOC and FMOC as derivatization reagents. The ratios of l(BCIC)/l(CEOC) and l(BCIC)/l(FMOC) are, respectively, 1.23-3.14 and 1.25-3.08 for fluorescent (FL) responses (here, l is relative fluorescence intensity). Separation of the derivatized amines had been optimized on reversed-phase Eclipse XDB-C-8 column. Detection limits are calculated from 1.0 pmol injection, at a signal-to-noise ratio of 3, are 10.6-37.8 fmol. The mean interday accuracy ranges from 94 to 105% for fluorescence detection with the largest mean %CV < 7.5. The mean interday precision for all standards is < 6.0% of the expected concentration. Excellent linear responses are observed with coefficients of > 0.9997.

洞穴滴水溶解有机碳三维荧光光谱特征及其对环境的响应: 以贵州4个洞穴系统为例

荧光光谱是洞穴次生沉积物古环境、古气候重建的重要指标之一, 充分理解产生洞穴次生沉积物的滴水的荧光变化对现代环境、气候的响应关系, 是较好利用该指标的关键. 利用三维荧光光谱分析4 个岩溶洞穴系统溶解有机碳(DOC)荧光特征, 结果表明洞穴系统中土壤水及洞穴滴水中的DOC 荧光类型主要以类富里酸荧光和类蛋白荧光为主; 类富里酸荧光强度与DOC 浓度有很好的线性关系, 指示了洞穴滴水DOC 来自洞穴上覆土壤层. 洞穴滴水类富里酸荧光在林地覆盖下的凉风洞激发发射波长变化较小, 激发波长相对于其他3 个洞穴滴水的稍长, 而荧光强度变化较大; 灌草丛覆盖的将军洞激发发射波长及荧光强度变化最大, 激发波长较短, 揭示洞穴系统上覆植被的变化明显地影响到滴水的荧光光谱特征.