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1.
本工作研究了冠醚化合物在外延乳剂生长过程中的调变作用。结果表明,1,4,7,10,13,16-六氧杂环十八烷对AgBr八面体乳剂无侵蚀作用,对非同晶系晶体之间的外延不起调变作用。1,7,10,16-四氟-4,13-二氮代杂环十八烷均使AgBr八面体乳剂的棱角产生了不同程度的侵蚀,可充当不同晶系晶体外延生长的调变剂,对晶体的溶解侵蚀能力依2S-18-C-6,2N-18-C-6,18-C-6的次序降低。这与它们同Ag+络合能力的强弱一致。2S-18-C-6,2N-18-C-6仅对非同晶系晶体之间的外延起调度作用,而对同晶系晶体的外延不起调查作用。冠醚化合物对晶体外延生长的调变作用与冠醚化合物对晶体的络合溶解作用有关。  相似文献   

2.
近年来国内外相继报道了在冠醚核心上引入取代基合成出一系列具有液晶特性的冠醚化合物,它们除具有普通液晶的电光、电磁及超声等特性外,还具有选择性络合金属离子的能力。研究这类化合物结构及性能将有助于选择和制备对金属离子具有高度识别能力的输送膜。为此,我们研究了以二苯并-18-冠-6(DB-18-C-6)及苯并-15-冠-5(B-15-C-5)为核心衍生的胆甾型冠醚化合物。经红外、核磁、质谱及元素分析确定其结构,由差热分析和偏光显微镜观察证明其具有液晶特性,并用电导法探讨了该系列液晶化合物与KClO_4在25℃时的络合特性,测定了络合比及络合常数。  相似文献   

3.
含有离子交换基的冠醚共缩聚物的合成与性能   总被引:2,自引:0,他引:2  
本工作采用对磺酸基(羧酸基)苯酚与甲醛反应生成的2,6—二羟甲基—4—磺酸基(羧酸基)本酚二钠盐与单苯并冠醚、二苯并冠醚缩聚,合威了两个不同系列高度水浸润性冠醚聚合物;测定了它们的溶胀性、热稳定性和络合性能。这类新型冠醚聚合物的络合能力显著优于相应冠醚聚合物,其中P_sBl5C5动态络合容量(Ag~+)最高:1.3mmol/g。  相似文献   

4.
赵明  张青莲 《应用化学》1989,6(2):48-51
制备了两种新的锂盐冠醚络合物:LiBr·(15-C-5)·H_2O和LiTFA·(18-C-6)·3H_2O。测定了二种锂盐LiCl、LiBr的(15-C-5)络合物和四种锂盐LiCl、LiBr、LiClO_4LiTFA的(18-C-6)络合物的中红外光谱,对主要吸收峰进行了指认,表明各种锂盐上的Li~ 都直接与醚环上的氧络合。由于不同锂盐的配位水形成氢键的差异,锂盐(15-C-5)络合物中配位的V_(OH)波数大小顺序为,LiClO_4>LiCl>LiBr,而锂盐(18-C-6)络合物中配位的V_(OH)波数大小的顺序为LiClO_4>LiTFA>LiBr>LiCl。此外,LiTFA盐中TFA~-的构型属Cs点群,呈双齿配体,但与Li~ 配位后,由于构型变化,发生谱带分裂和频率移动。  相似文献   

5.
本文报道了一种合成硫杂冠醚聚合物的新方法。以聚(2′-氯乙基-2,3-环硫丙基醚)为预聚物与二巯基化合物通过大分子反应直接环化,一步法合成了四种以聚硫醚为主链的新型硫杂冠醚聚合物(PD1-PD4)。并测定了它们对Ag~+、Au~(3+)、Pd~(2+)、Pt~(4+)、Cu~(2+)、Hg~(2+)、Zn~(2+)、Cd~(2+)、Pb~(2+)、Mg~(2+)、K~+、Ns~+等金属离子的络合性能。结果表明:它们除不络合K~+、Na~+、Mg~(2+)、Pb~(2+)外,对其它八种离子有不同程度的络合,其中对Ag~+、Au~(3+)、Pd~(2+)等贵金属离子的络合容量较高。  相似文献   

6.
本文用不同溶剂的冠醚溶液为流动相,硅胶G为固定相,对碱金属离子的薄层层析行为进行了研究。探讨了冠醚种类及浓度、不同阴离子种类及浓度、展开剂的酸度、薄层厚度和活化温度对R_f值的影响。结果表明,冠醚浓度增加,络合能力增强,其顺序为18-C-6>B-15-C-5>D B-24-C-8。相匹配的阴离子不同,络合物的R_f值也各异,顺序是三氯乙酸>苦味酸。当选用三氯甲烷-甲醇-甲酸(9:9:2,V/V)的18-C-6(0.1mol/L)溶液为展开剂时,可以分离(R_f)K~+(0.70)-Rb~+(0.48)-Cs~+(0.33)的混合物。  相似文献   

7.
通过双羟甲基 - 18-冠 - 6与烯丙基氯反应得到双烯丙氧甲基 - 18-冠 - 6,以之为原料 ,与不同量的含氢硅油加成制备出 5种新型有机硅聚合物冠醚 ,同时测试了它们对K+和Na+的络合容量。  相似文献   

8.
本文应用反相纸色层法和静态吸附平衡法检测了王冠化合物与稀土离子之间的络合能力和水相阴离子类型对络合能力的影响。所用的王冠化合物有:B-15-C-5,DB-18-C-6,四氢呋喃丙酮四聚体,DB-18-C-6-甲醛缩聚物和B-15-C-5-甲醛缩聚物。得到如下主要结果:1.不同王冠化合物的络合能力顺序是;B-15-C-5>DB-18-C-6》四氢呋喃丙酮吗聚体,另B-15-C-5-甲醛缩聚物>DB-18-C-6-甲醛缩聚物。2.稀土离子络合能力的顺序是:Sm3+Er3+=La3+(反相纸色层法),Er3+>Eu3+>La3+(吸附平衡法)。3.与不同阴离子缔合的离子对的稳定性顺序是:苦味酸根>三氯代乙酸根>磺基水杨酸根》Cl-、NO3-、ClO4-及SO4=。  相似文献   

9.
18-冠醚-6(18-C-6)和聚乙烯醇(PVA)改性海藻酸钠(SA)制备了阳膜层(18-C-6+m SA),戊二醛(GA)和PVA改性壳聚糖(CS)制备了阴膜液(m CS),将阴膜液流延于上述阳膜层上,制备了18-C-6+m SA/m CS双极膜。红外谱图表明18-C-6与海藻酸钠已成功交联。分别从双极膜的氢离子渗透性能、溶胀度、I-V工作曲线、交流阻抗、热稳定性能等方面表征了双极膜的性能,实验结果表明,经18-C-6改性的双极膜具有较低的溶胀度,较低的工作电压和膜阻抗,较高的氢离子渗透性能和热稳定性,是一种性能优异的双极膜。  相似文献   

10.
双冠醚与较大的金属离子能形成夹心型络合物,与相应的单冠醚相比较,它们具有更好的络合性和选择性。但双冠醚一般不溶于水中。本文用EDTA二酐与4'-氨基苯并-12-冠-4及4'-氨基苯并-15-冠-5反应,制得了两种在桥键上带有两个羧基的酰胺型双冠醚Ⅰ和Ⅱ。Ⅰ、Ⅱ未见报导,均能溶于水,这就可以象其它水溶性单冠醚一样,在水溶液中研究它们的络合行为。  相似文献   

11.
冠醚共缩聚物的合成与性能(Ⅱ)   总被引:1,自引:0,他引:1  
采用2,6-二羟甲基苯酚类化合物分别与单苯并冠醚(B15CS、B18C6)和M苯并冠醚(2B18C6、2B24C8、2B30C10)在酸催化下缩聚,合成了两个系列冠醚共缩聚物.这些聚合物M=1200—4500,可溶于氯仿等溶剂,萃取性能和络合选择性均有所提高.作为树脂使用,动态吸附容量为0.05—0.15mmol/g,并有较好的色谱特性.  相似文献   

12.
采用2,6-二羟甲基苯酚类化合物分别与单苯并冠醚(B15C5、B18C6)和二苯并冠醚(2B18C6、2B24C8、2B30C10)在酸催化下缩聚,合成了不同两个系列冠醚共缩聚物,这些聚合物M=1200-4500,可溶于氯仿等溶剂,萃取性能和络合选择性均有所提高。作为树脂使用,动态吸附容量为0.05-0.15mmol/g,并有较好的色谱特性。  相似文献   

13.
4′-氨基苯并-18-冠-6分别与间-硝基苯甲醛、对-硝基苯甲醛、间-苯二甲醛及其取代物和对-苯二甲醛缩合制得6种新的Schiff碱型单冠醚和双冠醚。4′-甲酰基苯并-18-冠-6分别与4′-氨基苯并-15-冠-5、4′-氨基苯并-18-冠-6作用制得2个醚环大小相同和不同的Schiff碱型双(苯并冠醚)。这些双冠醚经硼氢化钠还原得到相应的6种新的仲按型双冠醚。  相似文献   

14.
Crown ethers bound to microporous polystyrene resins by oxyethylene spacers were prepared by the reaction of monoazacrown ethers with 2-tosyloxyethoxymethylated or 2-(2-tosyloxyethoxy)ethoxymethylated polystyrene resins crosslinked with 2 mol % of divinylbenzene. The activity of the immobilized lariat crowns for halogen exchange reactions under triphase conditions has been studied as a function of catalyst structure, loading, substrate structure, reagent structure, and solvent. The lariat catalysts with extra oxygen donors in the spacer chain exhibited higher activity than the corresponding immobilized catalysts without the donors in the spacer. The increased activity of the catalyst containing 15-crown-5 unit and two extra donors for the reaction of 1-bromooctane with KI was concluded to result from the enhanced complexation with the K+ ion, induced by the cooperative coordination of the crown unit donors and the donors in the spacer chain. The recovered catalysts could be re-used without decrease in activity.  相似文献   

15.
双冠醚化合物对某些金属离子比单冠醚具有更好的络合性能和选择性,它们合成、应用研究越来越受到人们的重视,本工作采用2,6-二羟甲基对甲氧基苯酚为缩合剂与芳香族冠醚缩聚,得到一系列具有双冠醚结构特征的新酚醛型聚苯并冠醚(简称聚冠醚),聚冠醚合成容易,并呈现了比相应单冠醚更优越的络合萃取能力和富集效率。  相似文献   

16.
Allylation of sodium phenoxide in the presence of crown ethers produces a high ratio of O/O + C allylation when conducted in water, phenol, benzene, or diethyl ether. The striking increase in the product ratios is attributed to specific complexation of the crown ethers that facilitate the dissociation of the ion pair aggregate of the sodioderivative in benzene or diethyl ether. The crown ethers may act as a phase transfer catalyst when the reaction is run in water. Furthermore, the O/O + C ratios of the allylation strongly depend on the kind of crown ethers used. To examine their effect the allylation of sodium phenoxide was studied with various crown ethers, such as 18-crown-6, benzo-18-crown-6, benzo-15-crown-5, poly(vinylmonobenzo-15-crown-5), and poly(vinylmono-benzo-18-crown-6), as catalysts. It was found that among these crown ethers poly(vinylmono-benzo-15-crown-5) was the most effective catalyst.  相似文献   

17.
Polymers that contain crown ether moieties at the side chain and are capable of forming rather tough film were synthesized by the polymer reaction of poly(vinyl alcohol) with formyl derivatives of aliphatic crown ethers such as 12-crown-4, 15-crown-5, and 18-crown-6. In the passive transport of alkali metal picrates across the poly(crown ether) membranes the permeation, particularly of alkali metals which tend to form intramolecular sandwich-type complexes with the crown ether rings, was retarded, compared with a poly(vinyl alcohol) membrane. The cation selectivities in the permeation of poly(crown ether) membranes differed significantly from those of poly(vinyl alcohol).  相似文献   

18.
Unique structures of novel ionophores of double-armed penta-crown ethers were successfully synthesized. Diaza 18-crown-6 was designed as the parent crown ring. The penta-crown ethers were prepared by the reaction of trimethylolpropane triacrylate (TMPTA) with diaza 18-crown-6 and further with 1-aza crown ethers through the Michael reaction. The newly synthesized penta-crown ethers were characterized by 1H NMR, 13C NMR, FAB mass spectrum, IR and elemental analyses, respectively.  相似文献   

19.
Redox active films have been generated via electrochemical reduction in a solution containing palladium(II) acetate and fulleropyrrolidine with covalently linked crown ethers, viz., benzo-15-crown-5 and benzo-18-crown-6. In these films, fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. Films show ability to coordinate alkali metal cations from the solution. Therefore, in solutions containing salts of alkali metal cations, benzo-15-crown-5-C60/Pd and benzo-18-crown-6-C60/Pd films are doped with cations coordinated by crown ether moiety and anions of supporting electrolyte which enter the film to balance positive charge. These films are electrochemically active in the negative potential range due to the reduction of the fullerene moiety. Reduction of the polymer is accompanied by the transport of supporting electrolyte ions between solution and solid phase. In solution containing alkali metal salts, the process of film reduction is accompanied by the transport of anions from the film to the solution. In the presence of tetra(alkyl)ammonium salts, transport of cations from the solution to the film takes place during the polymer reduction.  相似文献   

20.
The synthesis of a functionalized crown ether was accomplished in two steps by condensing 3,4-dihydroxybenzaldehyde with bis(2-chloroethyl)ether and subsequent reduction of the reaction product, bis(formylbenzo)-18-crown-6 (4) to a diol (5). Polyurethanes that bear the dibenzo-18-crown-6 moiety in the polymer backbone were synthesized from bis(methylolbenzo)-18-crown-6 (5), a polypropylene glycol, and methylene bis(4-cyclohexyl isocyanate). The resulting polymers were fibrous white solids with glass transitions from ca. 15–120°C, depending on the starting diol composition. The thermomechanical spectra of melt pressed or solvent cast films of several crown-ether-bearing polyurethanes showed evidence of multiphase character. The polymers failed to complex effectively with sodium ions. However, their complexing ability with potassium ion was similar in magnitude to that observed with relatively simple crown ethers.  相似文献   

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