Supramolecular assemblages from uranyl complexes of calixarenes and potassium complexes of 18-crown-6 or dibenzo-18-crown-6

Reaction of uranyl nitrate with p-tert-butyl[3.1.3.1]homocalixarene (L¹H₄) or p-tert-butylcalix[8]arene (L²H₈) has been carried out in the presence of KOH and 18-crown-6 (18C6) or dibenzo-18-crown-6 (db18C6), giving the supramolecular assemblages [K(db18C6)(H₂O)₂]₃ [{UO₂(L¹)}₂K(H₂O)₅] (1) and [K(18C6)(OH)₂][{(UO₂)₂(L²H₅)(OH)}{K(18C6)}] (2). Compound 1 comprises a sandwich, “complex-within-complex” assemblage in which two uranyl/calixarene complexes encompass a potassium/crown ether guest. A direct bond between uranyl and K(18C6) is present in 2, in which a columnar arrangement of alternate dimetallic calixarene complexes and potassium/crown ether species is formed.     

含二苯并-18-冠-6单元的酰胺型双臂冠醚化合物的合成

合成了２个含二苯并－１８－冠－６单元的酰胺型双臂冠醚化合物,其结构经ＩＲ、＾１ＨＮＭＲ、ＭＳ和元素分析确证,该２个化合物都不具有液晶性,探讨了冠醚结构与液晶性的关系。     

Extraction of lead with nitrobenzene solution of strontium dicarbollylcobaltate in the presence of 18-crown-6

From extraction experiments with ⁸⁵Sr as a tracer, the extraction constant corresponding to the equilibrium Pb²⁺(aq) + SrL²⁺(nb) ⇄ PbL²⁺(nb) + Sr²⁺(aq) taking place in the two-phase water – nitrobenzene system (L = 18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K_ex(Pb²⁺, SrL²⁺) = 1.5. Further, the stability constant of the PbL²⁺ complex in nitrobenzene saturated with water was calculated: log β_nb(PbL²⁺) = 12.9.     

基于二苯并-18-冠-6基体改性的K+选择性离子交换膜的制备及性能研究

基于18-冠-6醚环腔体可与K⁺形成1∶1型稳定的络合物,通过掺杂的方式将4,4'-二氨基-二苯并-18-冠-6（A18C6）引入离子交换膜基材料中并成膜,然后利用1,3,5-苯三甲酰氯（TMC）对A18C6分子进行交联固定,制得一系列改性阳离子交换膜。通过改变A18C6的含量和TMC的反应时间来调控阳离子交换膜的基体结构,系统考察了改性膜在K⁺/Mg²⁺、K⁺/Na⁺ 和K⁺/Li⁺的二元体系中对K⁺的电渗析选择性。研究结果表明,在电流密度为5.0 mA·cm^-2的条件下,最优膜M-A18C6-10%-T30在K⁺/Mg²⁺和K⁺/Li⁺体系中对K⁺的选择性（P_{\mathrm{M}{\mathrm{g}}^{\mathrm{2}+}}^{{\mathrm{K}}^{+}}=\mathrm{6.96},P_{\mathrm{L}{\mathrm{i}}^{+}}^{{\mathrm{K}}^{+}}=\mathrm{3.73}）高于商业的单价选择性阳离子交换膜CIMS（P_{\mathrm{M}{\mathrm{g}}^{\mathrm{2}+}}^{{\mathrm{K}}^{+}}=\mathrm{5.36}）。A18C6的掺杂引入不仅提高了膜基体的致密性（孔径筛分效应）,也为K⁺在膜基体中的传输提供了新的离子传输通道（离子-偶极作用）。     

Mass transfer study in a pulsed bed electrode - application to the electrodeposition of a poly(dibenzo-18-crown-6) film

The polymerization of dibenzo-18-crown-6 has been carried out in an electrochemical reactor containing a granular electrode percolated by a pulsed solution. The influence of different parameters (pulse frequency, permanent flow velocity of the electrolytic solution, particle diameter and bed height) on the mass transfer has been studied. A correlation between the reduced mass transfer coefficient and the Strouhal number has been established. The maximum mass transfer coefficient and the maximum Strouhal number have been determined as a function of the Galilee number. The correlation predicts well the mass transfer coefficient over a larger range of the variables than previously achieved.     

Heterogeneous fluorination of chlorine containing polymers with 18-crown-6 as phase transfer agent

Effectiveness of alkali metal fluorides, complexed with crown ethers, as fluorinating agents, was investigated in nitrobenzene as mediating solvent. Partial fluorination of the surface of the crosslinked film of chlorinated polyethylene occurs within the first 2 h at 80°C. Further reaction leads to dehydrochlorination only. Up to 50% of chlorine in polyepichlorhydrin (Herchlor-H) may be replaced by fluorine. Further reaction is strongly inhibited by the presence of fluorine substituents in the neighbourhood of unsubstituted chlorines. ‘Plateau’ is reached after about 10 h at 140°C. In all investigated systems elimination, E, competes with substitution, S. It was suggested that the same transition state complex may be responsible for the two reactions. The energy of activation of the two processes is ～5 kcal mol^?1. The $\text{S}\text{E}$ ratio decreases in the following order: primary > Secondary >>> vicinal.     

Soluble,polymeric condensate of dibenzo-18-crown-6 and formaldehyde; synthesis,characterization and absorption of anionic copolymers

Dibenzo-18-crown-6 and formaldehyde polycondensate (PDBCO, M_w = 6760, soluble in CHCl₃ and in 2-methyl-1-pyrolidone (NMP) was synthesized by condensation in NMP using formic acid as catalyst. Alternatively, a sequence of reaction steps, involving sodium bromide salts, for solubilization (see Scheme 1) was worked up. PDBC as its sodium bromide complex is compatible with polysulfone derivatives. PDBC was found to be active in KSCN transport across a liquid membrane. Membranes cast from PDBC were also compared in adsorption of anionic proteins (PGT) with sulfonated polysulfone (SPS) or aminated polysulfone (APS). The absorption of PGT on PDBC membrane is strongest, but reversible. Thermal decomplexation of the cations neutralizes the cation-charged membrane and causes elution of the anionic PGT polymer.     

丙氧基—18—冠—6硅胶键合固定相的合成及色谱性能的研究

以多孔硅胶为基质,固相合成并制备了一种新型丙氧基-18-冠-6键合固定相(P18-C-6 SB),详细研究了其合成反应条件。P18-C-6 SB 是一种热稳定性好、耐溶剂,表面键合浓度高的色谱固定相。已应用于芳香族异构体及同系物的分离。     

超声波法合成二苯并-18-冠-6

采用超声波反应器，以邻苯二酚、二甘醇和对甲基苯磺酰氯等为原料，二甲亚砜为溶剂，氢氧化钾为催化剂兼模板剂，合成二苯并-18-冠-6（DB18C6）。产物经IR和^1HNMR表征。合成收率达到42％。较之传统方法具有操作简单、反应时间短、反应条件温和等优势。     

Effect of charge on anion and cation binding to poly(vinylbenzo-18-crown-6) in water

Complex formation constants, K, of cation to poly(vinylbenzo-18-crown-6) (P18C6) and to its monomeric analogue 4′-methylbenzo-18-crown-6 (MB 18C6) were measured in water potentiometrically or spectrophotometrically. The constants for Na⁺, K⁺ and Cs⁺ to P18C6, extrapolated to zero charge density, were found to be 2.4, 110 and 300 M^?1, respectively, and 27, 110 and ≈20 for MB18C6. Binding of K⁺ and of picrate anions to P18C6 was measured as a function of the number of K⁺ ions, Z, on the P18C6 chain. The charge effect (a decrease in K⁺ binding with increasing Z, and an increase in picrate binding) can be reasonably well-described by assuming the macroion to be a solvent- and ion-impenetrable sphere, the potential of which can be calculated by using a Debye-Huckel approximation. A linear plot is predicted and found (at least for picrate binding) between InK and Z, the slope yielding information on the radius of the P18C6 macroion. The cation effect on picrate binding to P18C6 was utilized to determine spectrophotometrically the order of binding of a series of cations to P18C6. The results were confirmed by using the dye, 2-(4′-hydroxybenzeneazo)benzoate which produces a much larger bathochromic shift on binding to P18C6 in water than does the picrate anion.     

Synthesis of formaldehyde-dibenzo-18-crown-6 condensation resins containing phosphonic acid groups and their alkali-metal cation sorption

Ion-exchange resins are prepared by introducing phosphonic acid monoethyl ester or phosphonic acid groups into formaldehyde condensation poly(dibenzo-18-crown-6) resin. The phosphonic acid ion-exchange groups provide accessibility for metal cations, while the ion-selective cyclic polyether binding site influences the selectivity. The selectivities and efficiencies for competitive alkali-metal cation sorption from aqueous solutions by these crown ether-containing phosphonic acid resins are strongly influenced by the pH of the aqueous solution, the identity of the phosphonic acid groups, and the molar ratio of ion-exchange groups to crown ether units. © 1995 John Wiley & Sons, Inc.     

Electroluminescent Performances of Iridium Complexes with Dibenzo-18-crown-6

Three novel iridium complexes with dibenzo-18-crown-6 substituted 2-penylpyridine (ppy) ligand have been synthesized and characterized. In order to investigate the electroluminescent properties of the resulting iridium complexes, polymer light-emitting diodes (PLEDs) with device structure of ITO/PEDOT:PSS/Emissive Layer/LiF/Al are fabricated using soluble poly(N-vinylcarbazole) (PVK) as the host and the resultant iridium complexes as dopant. Consequently, the PLEDs with G1 as dopant exhibited the highest luminous efficiencies of 13.3 cd A^?1 and the maximal brightness of 13523 cd m^?2 at the doping concentration of 8 wt%. Moreover, the iridium complexes G1, G2 and G3 exhibited nearly identical Commission Internationale de L’Eclairage (CIE) coordinates of (0.34?±?0.1, 0.62?±?0.1), which are very close to the CIE coordinates of (0.33, 0.61) for Ir(ppy)₃. This indicates that the CIE coordinates of the iridium complexes would not be influenced as the dibenzo-18-crown-6 groups pended on the meta-position of benzene ring of ppy.     

Inorganic anion regulated phase transition in a supramolecular adduct: 4-Trifluoromethoxyanilinium hexafluorophosphate-18-crown-6

A new supramolecular adduct 4-trifluoromethoxyanilinium hexafluorophosphate-1,4,7,10,13,16-hexaoxacyclooctadecane ([C₇H₇NOF₃–(18-crown-6)]⁺[PF₆]⁻) was synthesized and separated as crystals. DSC measurement detected that this compound undergoes a reversible phase transition at about 158 K with a heat hysteresis of 4.8 K. The single crystal X-ray diffraction data obtained at 213 K and 113 K suggest that the phase transition undergoes from a high temperature phase with a space group of Pnma to a low temperature one with a space group of P2₁/n, the symmetry breaking occurs with an Aizu notation of mmmF2/m. The driving force of the transition may be ascribed to the order–disorder transformation of the inorganic PF₆⁻ anion. Broad peak dielectric anomaly observed at 157 K further confirms this phase transition.     

二苯并-18-冠醚-6/聚醚嵌段酰胺膜富集水中苯酚性能研究

为提高聚醚嵌段酰胺 （PEBA）膜对水中苯酚的选择分离性能,采用二苯并-18-冠醚-6 (CE) 对PEBA膜进行改性制备了PEBA/CE渗透蒸发膜。通过FT-IR、SEM表征证实了CE与PEBA紧密结合且CE均匀分布在膜表面;AFM表征表明CE的修饰有效地提高了膜表面与苯酚的接触面积;水接触角测试表明CE的修饰极大地提高了PEBA/CE膜的疏水性。同时系统地研究了膜中CE含量、原料液苯酚浓度、进料温度对膜渗透汽化性能的影响,结果表明CE能显著提高PEBA膜对苯酚的选择性,在料液苯酚为0.8%（质量）及70℃操作温度条件下,当CE 的添加量为PEBA的6%（质量）时,PEBA/CE-6膜的分离因子和渗透通量分别为23.34和494.40 g/(m²·h),远超PEBA膜性能[分离因子8.46,总渗透通量547.48 g/(m²·h)]。长期性能稳定性测试表明所制备PEBA/CE-6膜具有良好稳定性,具有较好的工业运用潜力。     

水化在18-冠醚-6对K+和Na+选择过程中作用的理论研究

A combination of molecular dynamics (MD) and density functional theory (DFT) calculations were used to study the hydration structures of K+ and Na+ ions under the confinement of 18-crown-6 in order to identify the role of water in the selectivity of 18-crown-6 towards K+. The radial distribution functions, coordination numbers, orientation structures and interaction energies were analyzed to investigate the hydration of K+ and Na+ in 18-crown-6/cation complexes. All calculations of K+ and Na+ in bulk water were also conducted for comparison. The simulation results show that the orientation distributions of the water molecules in the first coordination shell of K+ are more sensitive to the confinement of 18-crown-6 than those of Na+. It is more favorable to confine a K+ in 18-crown-6 than a Na+ in terms of interaction energy. Good agreement is obtained between MD results and DFT results.     

Selective transport of a cupric-nickel-cobalt ion ternary system through cation ion-exchange membranes with a complexing agent by dialysis

The selective transport behaviors of metal ions for a ternary ion system through a cation-exchange membrane were studied in a stirred batch dialyzer. Cu⁺²-Ni⁺²-Co⁺² was chosen for the experiment. Malonic acid, oxalic acid and citric acid were employed as the complexing agent used in the solution in order to increase the discrepancy between transport fluxes of metal ions. The experimental results show that the order of effective complexing agents is citric acid> malonic acid > oxalic acid. The stoichiometric ratio of complexing agent to metal ions and the pH value of the feed solution are the primary factors on the selective transport behavior of metal ions. The optimal results of P_Co-Na:P_Ni-Na: P_{Cu_Na} can be attained about 5.40:3.75:0.75. A theoretical model of the system was formulated on the basis of the Nernst-Planck equation and interface equilibrium hypothesis. Theoretical solutions obtained by numerical calculation were in agreement with the results within a 15% deviation.     

Non-linear effect of 18-crown-6 in propylene oxide polymerization with potassium glycidoxide used as the inimer

A new initiating system containing potassium glycidoxide as the inimer and 18-crown-6 as the activator was used for propylene oxide polymerization. It was found that the rate of the reaction increased together with the crown ether concentration in a rather unexpected way. Two maxima of that parameter were found in the case of crown ether : inimer molar ratio equal to 3:1 and 6:1. On the other hand, the molecular weight of polymers showed two minima in those conditions. The heterogeneity of the reaction mixture and interactions between species present in the system could be responsible for the phenomena observed. The polydispersity of the polymers obtained was equal to about 1.2 and it was independent of the crown ether concentration.     

Mobility of Na+ in PVC membranes containing valinomycin and di-benzo-18-crown-6

We report bulk resistance measurements on PVC membranes containing varying proportions of NaBPh₄ and either valinomycin or di-benzo-18-crown-6. From an analysis of these measurements we have been able to demonstrate the lower mobility of Na⁺ when complexed by valinomycin or di-benzo-18-crown-6 compared with “bare” Na⁺.     

双水相体系萃取分离金属离子研究进展

双水相体系是一种绿色环保的新型分离技术,应用领域相当广泛,是近年来的研究热点。论述了双水相体系用于萃取分离金属离子的研究现状。根据所使用萃取剂的不同分3种情况进行了论述：不添加任何萃取剂直接萃取金属离子;以无机阴离子为萃取剂,依靠金属阳离子与无机阴离子形成的阴离子配合物（螯合物）而转移到萃取相,萃取金属离子;采用有机试剂作为萃取剂,依靠金属离子与萃取剂反应形成的中性配合物（螯合物）而转移到萃取相,萃取金属离子。论述了双水相体系萃取分离金属离子的发展趋势：建立金属离子在双水相体系中分配的机理模型;双水相体系成相物质的回收及再利用;通过无机盐水化能力的差异,或者通过双水相体系的温度诱导相分离,实现无机盐的分离与常温制备;开展双水相体系萃取分离金属离子的工程研究。