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某些铁—硫原子族络合物紫外—可见光谱的研究 总被引:1,自引:1,他引:0
本文研究了某些铁-硫原子簇络合物紫外-可见光谱220-230nm吸收带λmax的浓度效应;△λnm随络合物结构对称性增加而减小,随浓度基数增大而变大的变化关系。该类型络合物紫外-可见光谱吸收峰的归属,计算了Fe^II分裂能△值;配体上的取代基效应,以用在二氯甲烷等溶剂中的溶剂效应。 相似文献
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在二氯甲烷溶剂中对有机铁硫原子簇配合物进行了紫外光谱(190~400 nm)研究发现,π-π~*跃迁紫外吸收峰的λ_(max)随溶液浓度的增加明显红移,而对含孤立C—S键或C—O键化合物未见明显移动。本文还研究了一些含n-π、π-π共轭化合物的紫外光谱,发现除π-π跃迁λ_(max)随溶液浓度增加红移外,π-π~*跃迁λ_(max)还随溶液浓度增加发生蓝移。 相似文献
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研究了8个新合成的四取代苯基卟啉氯化铁络合物的紫外-可见光谱,对在三氯甲烷溶剂中荷移带约240nm处λmax随测试溶液浓度增加而红移的规律进行了计算机拟合,拟合修正公式为λmax=e^a+bc^e,相关系数达0.998,本文用拟合公式对络合物含量进行测定,相对误差为0.05 ̄4.9%。本文还对该系列络合物的紫外-可见光谱主要吸收峰作了归属,也研究了取代基效应。 相似文献
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[5,10,15,20]—四取代苯基卟啉氯化锰配合物紫外—可见光谱… 总被引:3,自引:0,他引:3
测定了18个新合成的四代苯基卟啉氯化锰的紫外-可见光谱,对主要吸收峰作了归属,指定了CT带,研究了样品在四氢呋喃溶剂中220nm附近吸收带的浓度效应和在四氢呋喃、三氯甲烷、二氯甲烷、乙醇中的溶剂效应及取代基效应。结果表明,除o-Me,p-I取代苯基卟啉锰外,220nm附近吸收带随测试溶浓度增加,λmax红移;随测定溶剂极性(P值)增加,λmax蓝移。 相似文献
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测定了18个新合成的四取代苯基卟啉氯化锰的紫外-可见光谱,对主要吸收峰作了归属,指定了CT带,研究了样品在四氢呋喃溶剂中220nm附近吸收带的浓度效应和在四氢呋喃、三氯甲烷、二氯甲烷、乙醇中的溶剂效应及取代基效应。结果表明,除o-Me、p-Ⅰ取代苯基卟啉锰外,220nm附近吸收带随测试溶液浓度增加,λ_(max)红移;随测定溶剂极性(p值)增加,λ_(max)蓝移。 相似文献
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利用Vaspec-2048-2紫外光谱仪和Renishaw InVia型共聚焦拉曼光谱仪,测量了极性溶剂1,2-二氯乙烷碘溶液中的β-胡萝卜素的紫外-可见吸收光谱和拉曼光谱.结果表明,生成络合物的β-胡萝卜素在460 nm处的紫外-可见吸收峰消失,并在1000 nm处出现β-胡萝卜素与碘形成络合物的吸收峰,致使514.5 nm激光激发时观察不到络合物中C-C(C—C,C=C)键的共振拉曼光谱.而溶液中没有形成络合物的β-胡萝卜素的C-C键拉曼散射截面减小.其机理为:β-胡萝卜素和碘溶液不稳定,β-胡萝卜素分子结构有序性减弱,导致相干弱阻尼C-C键振动减弱,使得其拉曼散射截面减小. 相似文献
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新显色剂2-(2-咪唑偶氮)-5-二乙氨基苯胺与钯显色反应的研究 总被引:3,自引:0,他引:3
研究了新显色剂2-2-(咪唑偶氮)-5-二乙氨基苯胺(IZAEA)与Pd2+显色反应的条件。试验结果表明,在pHL5. 0的HOAc-NaOAc介质中,试剂与Pd2+形成稳定的紫红色络合构,此络合物不被强酸分解,其它金属离子与试剂形成的有色络合构均被强酸分解。络合物的λmax为564nm,试剂的λmax为476nm,对比度△λ为88nm,Pd2+与试剂的络合比为l2,表观摩尔吸光系数为2.81×104L·mol-1·cm-1,Pdz+浓度在0~0.8mg·L-1范围内遵守比耳定律。所拟方法直接测定催化剂和分子筛中微量钯,结果满意。 相似文献
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钍(Ⅳ)与偶氮溴膦-mB和溴化十四烷基吡啶在乙醇-水溶液中的显色反应及其分析应用 总被引:1,自引:0,他引:1
在pH1~2的酸性介质中,钍(Ⅳ)与偶氮溴膦-mB(BPAmB)形成最大吸收波长(λ_(max)位于686nm的蓝色络合物,摩尔吸光系数(ε)为8.27×10~4L·mol~(-1)·cm~(-1).在有少量乙醇存在的0.5~1.0 mol/L盐酸溶液中,钍(Ⅳ)能与BPAmB和溴化十四烷基吡啶形成更灵敏的三元络合物,最大吸收位于695nm,具有更大的对比度(△λ=135nm)和更高的灵敏度.ε值达1.41×10~5L·mol~(-1)·cm~(-1),是目前光度法测定钍(Ⅳ)灵敏度最高的显色反应之一,Th(Ⅳ)的浓度在0~800μg/L范围内遵守比尔定律.方法具有良好的选择性,此法用于岩矿中微量钍的测定,结果满意. 相似文献
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二乙胺液相催化羰化制备二乙基甲酰胺 总被引:1,自引:0,他引:1
考察了反应压力、催化剂、助催化剂和反应温度对二乙胺(DEA)液相羰基化合成二乙基甲酰胺(DEF)反应的影响,确定了量佳反应条件.结果表明,CO分压(P∞)对反应有明显影响,生成DEF的速率随P∞增大而增大;催化剂浓度对反应的速率影响较小,添加剂环氧丙烷(PO)对催化剂有较强的助催化作用,而且助催化作用随PO浓度的增加而增大,生成DEF的选择性随PO浓度的增加而降低,温度对反应也有明显的影响,确定最佳反应条件为:CO分压小于6.0MPa,反应温度为80℃至90℃,催化剂浓度不大于0.05mol/L,助催化剂PO浓度不大于4.0mol/L.此时选择性不小于96%. 相似文献
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Nighat Nazir Mohammad Syed Ahanger Arif Akbar 《Journal of Dispersion Science and Technology》2013,34(1):51-55
The effect of methanol, ethanol, and 1-propanol on cmc and degree of counter ion binding, β, of cetyltrimethylammonium bromide (CTAB) has been studied conductometrically. The micellization of CTAB in these water-alcohol media have been found to be both dependent on nature as well as the concentration of alcohol in water. The cmc values shift toward higher concentration with increase in alcoholic content up to certain concentration beyond which decrease in cmc is registered in case of all the alcohols. However, the maximum in the cmc versus concentration of alcohol shifts to lower concentration with the increase in number of carbons in alcohol. β shows the inverse peaked behaviour in conformity with the cmc variation. The effects viz. solvent modifying tendency of alcohols and their tendency of penetration into the micelles have been used to interpret their effect on micellization of CTAB. 相似文献
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Different types of industrially produced titanium dioxide nanoparticles and a precipitated titanium dioxide have been dissolved in aqueous NaCl solutions at temperatures of 25 and 37 degrees C. The titanium concentration in solution with regard to dependence on time has been determined up to 3000 h after starting the dissolution experiment. The effect of particle size, pH value, temperature, background electrolyte concentration, and mass concentration of titanium dioxide exposed to the liquid phase has been studied. The nanoparticles have been characterized by N2 physisorption measurements and XRD. The total dissolved titanium in solution has been determined by adsorptive stripping voltammetry (AdSV) and inductively coupled plasma mass spectrometry (ICP-MS). A new kinetic size effect has been observed. It turns out that this effect can be explained by applying an already existing phenomenological thermodynamic and kinetic model. The model describes all possible phenomena in a colloidal dispersion, nucleation, growth of particles, Ostwald ripening, and dissolution of particles using a uniform concept. 相似文献
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The adsorption and diffusion phenomena of Methylene Blue dye on glass fiber have been explored. Both isotherm and kinetics have been studied. Effect of process parameters such as pH, adsorbent loading, and initial dye concentration was investigated. Temperature had a little effect on adsorption. A diffusion model was developed to estimate the diffusivity of the dye in glass fiber. The diffusivity was found to be varying exponentially with the dye concentration. 相似文献
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淀粉和聚乙烯二者极性差别很大,如何提高淀粉/聚乙烯共混物降解塑料中两相的相容性是此项研究的技术关键.采用添加增容剂[1],或进行淀粉疏水改性[2],或对聚乙烯进行亲水改性[3]的办法均取得了一定的进展.本文在提高相容性研究的基础上,又添加油酸和有机铁... 相似文献
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《Journal of membrane science》1997,125(2):257-268
The studies on ion transport of terbium and dysprosium through a porous supported liquid membrane (SLM) containing TOPO (trioctyl phosphine oxide) and TBP (tributyl phosphate) as immobilised carriers have been carried out. The effect of stirring of bulk solutions on permeability coefficient has been investigated. The permeability coefficient increases with increase in pH of source phase from 0–6, and hydrogen ion concentration from 0.01 to 0.1 M of receiving solution. The dependency of permeability coefficient on the carrier concentration has been explored. The effect of ammonium thiocyanate concentration on permeability coefficient has been studied. In order to develop a method for enrichment of rare earth elements, further investigations were carried out by using a hollow fibre membrane extractor. The mechanism of ion transport of terbium and dysprosium in SLM systems has been explained. 相似文献
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《Journal of Coordination Chemistry》2012,65(13):2337-2348
An emulsion liquid membrane process using bis-(2-ethylhexyl) phosphoric acid (D2EHPA) to extract and separate Ni(II) and Co(II) from acidic chloride solutions is described. Liquid membrane consists of a diluent, a surfactant (Span 80), and an extractant (D2EHPA). Hydrochloric acid was used as the stripping solution. The important parameters governing the permeation of nickel and their effect on the separation process have been studied. These parameters are stirring speed, feed phase pH, surfactant concentration, extractant concentration, stripping phase concentration, phase ratio, initial concentration of metal, and treatment ratio. The optimum conditions have been determined. The separation factors of Ni(II) with respect to Co(II), based on initial feed concentration, have been experimentally determined. Furthermore, the extraction selectivity for Co(II) over Ni(II) has been improved by using D2EHPA during the initial minutes. 相似文献
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《液相色谱法及相关技术杂志》2012,35(6):937-947
Abstract A reverse phase thin layer partition chramotography has been performed on metal ions using silica gel G as an adsorbent. The effect of chlorosubstituent groups on the migration of cations has been studied. The use of aqueous solutions of acetic acid, monochloro, dichloro and trichloro acetic acid in the solvent system revealed profound effect of substituent groups on the Rf values of metal ions. The effect of concentration and pH of the mobile phases have been studied. Many qualitative ternary separations have been sucessfully achieved. 相似文献