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1.
锌(II)与2,2′ 联吡啶 1,1′ 二氧化物bypyO2形成的配合物主要有[Zn(bipyO2)3](ClO4)·2H2O、[Zn(bipyO2)3](PtCl4)·2H2O和[Co(bipyO2)2(NCS)2]等。我们在DMF溶剂中合成了锌(II)与bipyO2形成的三核配合物,测定了它的组成及IR谱气敏特性,发现对氨气有很高的敏感性和选择性。用它制作的传感器具有灵敏度高、选择性好、能耗低和常温下工作的特点,在涉氨化工生产的自动控制和氨气泄漏报警方面有一定的应用前景。1 实验部分bipyO2按文献[1]制备,经重结晶得白色晶体。C10H8N…  相似文献   

2.
氨三乙氧基三苯甲酸(NEB)(NEB·HCl的分子结构式见下图)作为有立体选择性的配体,它与铀酰离子UO2(Ⅱ)配位作用已有报导[1]。在对NEB质子化常数及二元体系M(Ⅱ)-NEB·HCl(M=Cd、Co、Ni、Cu和Zn)配合物的稳定常数测定的基础上[2],本文在25℃及离子强度为0 2mol/LKNO3的条件下,用精密pH电位法考察二元体系RE(III)—NEB(RE=La→Nd,Sm→Lu,Y)中存在的配合物物种及其稳定常数。NEB·HCl结构式1 实验部分1 1 试剂和仪器NEB·HCl(H3L·HCl,L3-=C27H24NO9)…  相似文献   

3.
由于稀土元素镧与氨基酸形成的配合物具有抗癌、抗肿瘤活性 ,人们对稀土氨基酸配合物的研究产生了浓厚兴趣。有关这类配合物的制备和表征的研究较多[1~ 4] ,而对其热化学性质的研究较少。我们按文献[5] 方法合成了配合物La(Tyr)(Gly) 3Cl3·3H2 O(s) ,在自行研制的具有恒定温度环境反应热量计上 ,分别测定了La2 O3(s)、氨基酸 [L 酪氨酸 (Lyr) +甘氨酸 (Gly) ]和配合物在2mol·L- 1 HCl溶液中的溶解焓 ,通过设计的热化学循环得出配合反应焓 ,进而计算出La(Tyr)(Gly) 3Cl3·3H2 O(s)的标准摩尔…  相似文献   

4.
采用半微量相平衡方法研究了LaCl_3·3H_2O-18C6-C_2H_5OH三元体系在25℃时的溶解度,测定了各饱和溶液的折光率。结果表明:该体系在25℃时形成了3种化学计量的配合物,组成分别为LaCl_3·18C6·3H_2O·2LaCl-3·18C6·6H_2O·C_2H_5OH及3LaCl_3·18C6·9H_2O·C_2H_5OH.考察了相平衡过程中水的行为,结果表明:无论在液相还是在固相中,H_2O/LaCl_3的摩尔比总是3:1.制备了固态配合物,用IR、DTG、TG与DSC研究了配合物的组成与性质。由DSC得到配合物不同分解步骤的焓变.  相似文献   

5.
采用半微量相平衡方法研究了Gd(ClO_4)_3·3H_2O-18C6-CH_3CN三元体系在25℃时的溶解度,测定了饱和溶液的折光率。结果表明,该体系在25℃时形成两种化学计量的配合物,其组成分别为:Gd(ClO_4)_3·18C6·3H_2O·2CH_3CN和Gd(ClO_4)_3·2(18C6)·3H_2O·2CH_3CN,制备了固态配合物,用化学分析及元素分析、IR、DTG、TG及DSC等研究了配合物的组成与性质。  相似文献   

6.
采用半微量相平衡方法研究了三元体系Y(ClO4)3·3H2O-B15C5—CH3OH在25℃的溶解度,测定了各饱和溶液的折光率.该体系在25℃生成三种化学计量的配合物,其组成分别为:4Y(ClO4)3·3B15C5·12H2O·12CH3OH(Ⅰ)、Y(ClO4)3·B15C5·3H2O·1.5CH3OH(Ⅱ)与Y(ClO4)3·2B15C5·3H2O·CH3OH(Ⅲ),其中配合物(Ⅰ)和(Ⅱ)是溶解不一致化合物.在甲醇溶剂中,分离制备了配合物(Ⅲ),在69—72℃下干燥得到配合物Y(ClO4)3·2B15C5·3H2O.利用IR光谱、电导测量及X-射线衍射分析对配合物进行了表征.  相似文献   

7.
采用半微量相平衡方法研究了PrCl_3·3H_2O-18C6-C_2H_5OH三元体系在25℃的溶解度,测定了各饱和溶液的折光率。在该体系中有三种比学计量的配合物形成,其化学组成为:2PrCl_3·18C6·6H_2O·C_2H_5OH、4PrCl_3·3(18C6)·12H_2O和PrCl_3·18C6·3H_2O,依据相平衡结果,合成了三种固态配合物,利用化学分析、IR、TG、DTG、DSC及电导研究了配合物的组成和性质。  相似文献   

8.
磷钨钴和磷钨镍杂多酸化学修饰电极的研究   总被引:3,自引:0,他引:3  
杂多酸由于组成和结构上的特点,在电化学和电分析化学领域有着广泛应用[1,2]。迄今为止,有关磷钨钴和磷钨镍三元杂多酸化学修饰电极还未见报道。本文按文献方法[3]合成了磷钨钴(H3PW11CoO40·xH2O)和磷钨镍(H3PW11NiO40·xH2O)杂多酸,分别以H3PW12O40·xH2O、H3PW11CoO40·xH2O和H3PW11NiO40·xH2O杂多酸(以下简写为H3PW11MO40·xH2O,其中M代表W,Co和Ni)为修饰剂,采用电化学方法在导电基体玻碳(GC)电极上制备了H3PW11MO40/GC膜修饰电极,制备过程简便、快速。对膜电极的…  相似文献   

9.
羟基磷灰石合成工艺研究   总被引:1,自引:0,他引:1  
羟基磷灰石 [Ca10 (PO4 ) 6(OH) 2 ,简称HAP]是80年代发展起来的新型牙科、骨科材料 ,其成份接近生物体骨质的无机成份 ,能诱发新骨生长 ,具有良好的生物相容性。HAP的制备方法较多 ,有溶胶 凝胶法[1,2 ] 、沉淀法、电化学合成法[3 ,4 ] 等。1 实验1 1 试剂与仪器所用试剂除磷酸三丁酯为化学纯外 ,其它都是分析纯。美国尼高力公司 (NICOLET)傅里叶变换红外光谱仪 (MAGNA 5 5 0 (Ⅱ ) )。1 2 HAP的制备1 2 1 溶胶 凝胶法合成HAP 我们以不同原料制备了HAP。第一种方法是以Ca(NO3)2 与磷酸三丁…  相似文献   

10.
采用半微量相平衡方法研究了Y(ClO_4)_3·3H_2O-Bl5C5-CH_3CN三元体系在20℃时的溶解度,测定了各饱和溶液的折光率.该体系于20℃生成两种化学计量的配合物,其组成分别为Y(ClO_4)_3·B15C5·3H_2O·2.5CH_3CN和Y(ClO_4)_3·2B15C5·3H_2O·CH_3CN。用IR光谱、电导、DTG、TG和DSC研究了配合物的组成和性质。  相似文献   

11.
Summary A colloidal solution of cobalt tungstate of negative charge and highly lyophilic character was prepared by mixing sodium tungstate and cobalt chloride solutions in presence of glycerine and caustic soda. The sol exhibits protective action against the electrolytic coagulation of hydrophobic sols of opposite electrical character. In its coagulation both the anions and cations follow theHofmeister series. The sol is highly viscous and exhibits the acclimatisation effect and also the ionic antagonism.  相似文献   

12.
The influence of various monovalent cations and of divalent calcium ions on colloidal fouling strength was investigated quantitatively on a bench-scale ultrafiltration device. A higher colloidal fouling potential (k) was consistently observed with lithium chloride compared to the same ionic strengths of chlorides of other monovalent cations (Na+, K+, and Cs+). This observation was attributed to the formation of an impervious layer around the colloidal particle by lithium ions that prevented the repulsive forces due to the interaction of the silica hairs formed on the particles in the presence of water. The impact of the divalent calcium ion on the fouling potential was more complex. The fouling potential first increased with calcium ion concentration and then decreased. The maximum value of fouling potential occurred at the ionic strength corresponding to the critical coagulation concentration, which decreased with increasing colloid concentration. The colloidal fouling potential was well correlated by a bilinear relationship with colloid concentration and ionic strength for all salts tested under the critical coagulation concentration.  相似文献   

13.
The rheological behaviour of aqueous suspensions of boehmite (AlO(OH)) modified with different Ce-salts (Ce(NO(3))(3), CeCl(3), Ce(CH(3)COO)(3) and Ce(2)(SO(4))(3)) was investigated at a fixed Ce/Al molar ratio (0.05). Freshly prepared boehmite suspensions were near-Newtonian and time-independent. A shear-sensitive thixotropic network developed when Ce-salts with monovalent anions were introduced in the nanoparticle sols. The extent of particle aggregation dramatically increased with ageing for Ce(NO(3))(3) and CeCl(3) whereas an equilibrium value was reached with Ce(CH(3)COO)(3). The addition of Ce(2)(SO(4))(3) with divalent anions involved no thixotropy but rather a sudden phase separation. The combined data set of IRTF and DRIFT spectra indicated that free NO(3)(-) anions of peptized boehmite adsorb on the nanoparticle surface by H-bond. The introduction of Ce-salts in the boehmite sol led to the coordination between Ce(3+) ions and NO(3)(-) anions adsorbed on boehmite i.e. to [Ce(NO(3))(4)(H(2)O)(x)](-) complex. Such coordination led to a thixotropic behaviour which was lower with Ce(NO(3))(3) compared to CeCl(3) and Ce(CH(3)COO)(3). In contrast, Ce(2)(SO(4))(3) formed insoluble complexes with dissolved aluminium species. The formation of H-bonded surface nitrate complexes was found to play a decisive role on the particle-particle interactions and consequently on the rheological behaviour of the sols.  相似文献   

14.
采用紫外分光光度法和荧光分光光度法研究了主体分子对二甲氨基苯甲酸与HPO42-、SO42-、H2PO4-、ClO4-、HSO4-、NO3-、BF4-、PF6-、F-、Cl-和Br-等11种阴离子客体的识别作用.发现在乙腈溶液中,该主体分子对二价阴离子HPO42-和SO42-表现了强亲和力和高选择性;并对一价阴离子F-和H2PO4- 具有一定的响应能力;而与一价阴离子ClO4-、HSO4-、NO3-、BF4-、PF6-、Cl-和Br-几乎没有作用.结果表明主客体分子本身的酸碱性和阴离子的负电荷数目是影响主体分子对阴离子识别性能的主要因素.  相似文献   

15.
十一钨锰硅酸盐异构体的电化学性质及其催化性能   总被引:4,自引:0,他引:4  
报道了十一钨锰硅酸盐异构体α-,β  相似文献   

16.
I. Isildak 《Chromatographia》1999,49(5-6):338-342
Summary An all solid-state contact tubular PVC-matrix membrane electrode has been applied for potentiometric detection of inorganic and organic monovalent anions using phosphate and hydrogen phosphate eluents at low concentrations. This is a “monovalent detection method” as the selectivity of the electrode towards monovalent anions results in some other anions being undetected unless the concentration of those other anions is higher than 10−3 mol dm−3 in the sample solution injected. It takes only eight minutes to complete the separation with a good resolution. Theoretical and practical considerations are discussed, and in particular, sensitivity, linearity, detection limit and dynamic behaviour are presented. The use of an all solid-state contact bromide-selective electrode as a detector offers so far the best simultaneous sensitivity toward all anions when compared with other detection methods. Determination of Cl and NO3 ions in river, rain and drinking water samples without any further sample preconcentration has been successfully achieved. The detection limit is sub-ppb for most of anions in a 20 μL injection volume.  相似文献   

17.
A new ion chromatographic (IC) system has been established by using micelles of 3-(N,N-dimethylmyristylammonio)propanesulfonate (Zwittergent 3-14) loaded onto a reversed-phase packed column as the separation column with an electronic rotary switching valve packed-bed suppressor for conductometric detection of inorganic anions. An aqueous H3BO3-Na2B4O7 solution has been demonstrated to be the most desirable eluent for this IC system. The relationship between retention time and the concentration of the borate eluent was determined for a series of model anionic analytes and this relationship was found to be opposite to that exhibited in a conventional anion-exchange IC system. The rapid elution and complete separation of monovalent inorganic anions were obtained by initially using a high-concentration borate solution as the eluent for a short-period, and then switching to a lower-concentration borate eluent to complete the separation. Detection limits for nitrite, bromide, nitrate, and chlorate were 0.85, 0.88, 0.95 and 4.8 microM, respectively, when a 7.0 mM Na2B4O7 eluent was used. Moreover, the ability to directly detect these monovalent anions in samples containing high concentrations of sulfate and/or chloride ions provided a major advantage of this approach.  相似文献   

18.
The constants of anion-exchange extraction of divalent ions by quaternary ammonium salts of various structures were determined. The exchange constants depend significantly on steric accessibility of the exchange site. For the exchange of small-size anions, the affinity of the ion exchanger for divalent ions is higher than for monovalent ions. For large divalent anions, the exchange constant may increase or decrease, depending on the size of a monovalent anion. The obtained results are explained by the specifics of the ion-pair association of monovalent and divalent anions with quaternary ammonium cations.  相似文献   

19.
Negatively charged silica sol is known to lead to fouling of anion exchange membranes during electrodialysis (ED) as a result of its deposition on the membrane surface. It is known that the fouling potential is related to the physical and electrochemical properties of the silica particles as well as those of the anion exchange membranes. In this study, the properties of the silica sol were characterized in terms of its particle size, turbidity, and zeta potential in order to predict their effects on the electrodialysis performance. In the stability of colloidal particles, the critical coagulation concentrations of silica sol were determined as functions of ionic strength, cation species, and solution pH. In the electrodialysis of NaCl solution containing silica sol with various concentrations of CaCl(2), the colloidal behavior related to deposition and transport was examined during and after electrodialysis. The electrodialysis experiments clearly showed that the deposition and transport of silica sol during electrodialysis were related to the colloidal stability of dispersion.  相似文献   

20.
The present work reports the parameterization of the polarizable continuum model for predicting the free energies of solvation for monovalent anions in acetonitrile and N,N-dimethylformamide. The parameterization of the model for acetonitrile employed the experimental free energies of solvation for a set of 12 charged solutes, containing H, C, N, O, S, F, Cl, Br, and I atoms. For the N,N-dimethylformamide solutions, experimental solvation free energies for 11 monovalent anions were used. A mean absolute error of 0.7 kcal/mol in the solvation free energies has been achieved for the 12 anions in acetonitrile, whereas the mean absolute error for the 11 anions corresponds to 0.5 kcal/mol in N,N-dimethylformamide. These results indicate that the polarizable continuum model is a suitable methodology for the study of thermodynamic effects in solutions of monovalent anions in both solvents.  相似文献   

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