Potassium-selective PVC membrane electrodes based on bis- and poly(crown ether)s

Potassium-selective PVC membrane electrodes based on bis- and poly (crown ether)s containing benzo-15-crown-5 moiety as neutral carrier were prepared and selectivity coefficients for various monovalent ions were measured in order to elucidate the effect of complexing property of these crown ether derivatives on the electrode response. In the preference for potassium over sodium of the electrodes, these bis- and poly (crown ether)s were found to exceed the corresponding monocyclic crown ether considerably, which reflects the easy complexation of stable 2:1 complexes of crown ether ring and ion, derived from the cooperative effect of two adjacent crown ether rings.     

The synthesis of bis(benzo-crown ether)s and their incorporation into potassium-selective PVC membrane electrodes

Five bis(benzo-15-crown-5) derivatives connected with different bridge chains were synthesized as neutral carriers in K⁺-selective electrodes. Potassium ion-selective PVC membrane electrodes based on these bis(crown ether)s were prepared using dibutyl phthalate (DBP) and dioctyl phthalate (DOP) as plasticizers of the PVC membrane. The selectivity coefficients (K _M ⁿ⁺:K _K+) for various alkali and alkaline-earth metal ions were measured. The electrodes based on the bis(crown ether)s are more selective for K⁺ than those based on monomeric crown ethers. The selectivity of one of the prepared potassium selective electrodes was higher than that of the electrode based on valinomycin and three of them were stable over a wide pH range.     

Guanidinium-selective PVC membrane electrodes based on crown ethers

Guanidinium-selective membrane electrodes were constructed with dibenzo-24-crown-8, dibenzo-27-crown-9, tribenzo-27-crown-9 or dibenzo-30-crown-10. The detection limits and selectivity coefficients towards different interfering ions, such as Li⁺, Na⁺, K⁺, NH⁺₄, Mg²⁺ and Ca²⁺ were determined. The electrode with dibenzo-27-crown-9 shows linear response over the range 10^?1–10^?4 M, with selectivity coefficients about 10^?2 for most alkali and alkaline earth metal ions.     

Simultaneous determination of sodium and potassium in human urine or serum using coated-wire ion-selective electrodes based on bis(crown ether)s

Summary High-performance coated-wire ion-selective electrodes based on dodecylmethyl bis(12-crown-4) and bis(benzo-15-crown-5) are used for the simultaneous determination of Na⁺ and K⁺ in human urine or serum by means of the Gran's plot method. The results of the potentiometric determination for Na⁺ and K⁺ in human urine or serum are in good agreement with the values obtained by flame photometry.

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Simultane Bestimmung von Natrium und Kalium in menschlichem Harn oder Serum unter Verwendung ionen-selektiver Elektroden aus Bis-Kronen-Ethern

Zusammenfassung Hochleistungsfähige ionen-selektive Elektroden auf der Basis von Dodecylmethyl-bis-(12-kronen-4)- und Bis-(benzo-15-kronen-5)-ether wurden für die simultane Bestimmung von Natrium und Kalium in menschlichem Harn bzw. Serum mit Hilfe von Gran's plot method verwendet. Die Ergebnisse der potentiometrischen Bestimmung stehen mit denen der Flammenphotometrie in guter Übereinstimmung.

     

邻菲咯啉冠醚衍生物为载体的伯胺药物电极及机理研究

合成了邻菲咯啉-18-冠-6等四种含邻菲咯啉结构的冠醚化合物, 并用作载体制备伯胺电极, 以苄胺为模型化合物, 研究了电极特性, 并制备了测试美西律药物的选择性电极。研究了实验条件对电极性能的影响。用正交多项式回归法优化电极的膜组成。苄胺电极的线性范围1.0×10^-5~0.1mol/L, 斜率55.6mV/pc, 检测下限2.0×10^-6mol/L。美西律电极的线性范围6.0×10^-6~0.1mol/L, 检测下限8.0×10^-7mol, 斜率58.0mV/pc。同时研究了冠醚推动伯胺穿透大块液膜的传输行为。     

Extraction of alkali metal picrates with poly- and bis(crown ether)s

Extraction of alkali metal picrates by new poly- and bis(crown ether)s containing benzo-15-crown-5 and benzo-18-crown-6 moieties was carried out with chloroform as water-immiscible solvent. The poly- and bis(crown ether)s were found to extract the picrates more effectively than the corresponding monocyclic crown ethers. In particular, poly- and bis(benzo-15-crown-5), and bis(benzo-18-crown-6) are remarkably effective extracting reagents for potassium and rubidium, and for caesium, respectively. Extraction equilibrium constants and the complexation constants in the chloroform phase were also evaluated and the contribution of the complexation constants to the extractability is discussed.     

Influence of the angle between two crown ether moieties on supramolecular copolymerization of bis(crown ether)s and bisparaquat homoditopic monomers

Bis(crown ether) homoditopic monomers containing two bis(p-phenylene)-34-crown-10 moieties with different angles(180° for monomer 3,120°for monomer 4,and 60°for monomer 5) and a complementary bisparaquat homoditopic monomer(7) were designed and synthesized.The three bis(crown ether) monomers could organize into linear supramolecular polymers in concentrated solutions in CHCl3/CH3CN with the bisparaquat monomer 7,as demonstrated by 1 H NMR and viscosity studies. The pseudorotaxanes or supramolecular polymers...     

Synthesis and properties of poly(ether imide)s based on a benzonorbornane bis(ether anhydride)

A novel bis(ether anhydride) monomer, 3,6‐bis(3,4‐dicarboxyphenoxy)benzonorbornane dianhydride, was synthesized from the nitro displacement of 4‐nitrophthalonitrile with 3,6‐dihydroxybenzonorbornane in the presence of potassium carbonate, followed by the alkaline hydrolysis of the intermediate bis(ether dinitrile) and the cyclodehydration of the resulting bis(ether diacid). A series of poly(ether imide)s bearing pendant norbornane groups were prepared from the bis(ether anhydride) with various aromatic diamines via a conventional two‐stage process that included ring‐opening polyaddition to form the poly(amic acid)s followed by thermal imidization to the poly(ether imide)s. The inherent viscosities of the poly(amic acid) precursors were 0.81–1.81 dL/g. The poly(ether imide) with m‐phenylenediamine as a diamine showed good organosolubility. Most of the cast poly(ether imide) films have had high tensile strengths and moduli. The glass‐transition temperatures of these poly(ether imide)s, except for those from rigid p‐phenylenediamine and benzidine, were recorded between 211 and 246 °C by differential scanning calorimetry. The softening temperatures of all the poly(ether imide) films stayed within 210–330 °C according to thermomechanical analysis. No polymers showed significant decomposition before 500 °C in a nitrogen or air atmosphere. A comparative study of the properties with the corresponding poly(ether imide)s without pendant substituents was also made. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1712–1725, 2002     

Solvent extraction of alkaline earth metal picrates with poly- and bis(crown ether)s

Summary Solvent extraction of alkaline earth metal picrates with poly- and bis(crown ether)s containing benzo-15-crown-5- and benzo-18-crown-6 moieties was carried out in a water-chloroform system. The poly- and bis(crown ether)s showed larger extractability for the metal picrates than the corresponding monocyclic crown ethers. Especially, poly- and bis(benzo-15-crown-5), and bis(benzo-18-crown-6) were found to have relatively high extractability and selectivity for Ba²⁺ and Sr²⁺, respectively.

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Lösungsmittelextraktion von Erdalkalipikraten mit Hilfe von Poly- und Bis-Kronenethern

Zusammenfassung Poly- und Bis-Kronenether mit Benzo-15-krone-5- und Benzo-18-krone-6-Einheiten wurden zur Extraktion von Erdalkalipikraten im Wasser-Chloroform-System verwendet. Die genannten Ether zeigten eine bessere Extraktionsfähigkeit für die Pikrate als die entsprechenden monocyclischen Kronenether. Im Falle von Ba²⁺ und Sr²⁺ ergab sich eine besonders gute Extrahierbarkeit und Selektivität mit Poly- und Bis(benzo-15-krone-5)- und Bis(benzo-18-krone-6)-Ethern.

     

Synthesis and multitopic complex formation of a photochromic bis(crown ether) based on benzobis(thiazole)

2,7-Bis[2-(6,7,9,10,12,13,15,16-octahydro-5,8,11,14,17-pentaoxabenzocyclopentadecen-2-yl)vinyl]-benzo[1,2-d;3,4-d']bisthiazole, 2, with crown ether styryl moieties substituted on a heterocyclic core, was synthesized and its complex forming ability with several metal cations was evaluated in acetonitrile by absorption and fluorescence spectroscopy. The results are compared to those for the analogous ligand possessing a single crown ether styryl moiety. Selective binding of the metal cation at the heterocyclic core of both ligands was observed only for Hg2+. Alkali and alkaline earth cations bind selectively at the crown ether moieties. Stability constants and pure spectra of defined stoichiometry were determined with the use of HYPERQUAD, a least-squares fitting program, and the results were validated in one case by subjecting the titration spectral matrix to singular value decomposition with self-modeling (SVD-SM). The multitopic ligand 2 forms relatively strong 2:2 stoichiometric complexes with K+, among the alkali metal cations, and Ba2+, among the alkaline earth metal cations, and is a promising selective optical sensor for these ions.     

Studies on bis(crown ether)-based ion-selective electrodes for the potentiometric determination of sodium and potassium in serum

Bis(crown ether)-based ion-selective electrodes for sodium and potassium are described, based on the bis[(12-crown-4)-2-ylmethyl]-2-dodecyl-2-methyl malonate sensor(I) for sodium and the bis[(benzo-15-crown-5)-15-ylmethyl] pimelate sensor(II) for potassium. The best results were obtained when the sensors were used in association with 2-nitrophenyl octyl ether as plasticising solvent mediator and potassium tetrakis(4-chlorophenyl)borate as anion excluder in poly(vinyl chloride) matrices. Electrode slopes were near-Nernstian, with detection limits of less than 10(-5) M. The electrode features are compared with those of a sodium glass membrane electrode, for sensor I, and with a valinomycin-based potassium electrode, for sensor II. The electrodes are also discussed in relation to others reported for sensors I and II and are shown to be superior. However, although the electrodes described offer promising alternatives to glass electrodes for sodium and valinomycin electrodes for potassium, data for sodium and potassium measurements in blood serum indicate a need for further research in order to improve the correlation with flame photometric measurements.     

Lead-selective membrane electrodes based on dithiophenediazacrown ether derivatives

Three double-armed diazacrown ethers with two thiophene side groups, 7,16-dithenyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DTDC), 7,16-dithenoyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DTODC), and 7,16-di-(2-thiopheneacetyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (DTAODC), have been synthesized and used as novel neutral lead(II) ionophores in ion selective electrode applications. The relationship between the molecular structure of these ionophores and electrochemical properties (linear range, response time, selectivity) of the membrane electrode is discussed. The optimum conditions for the preparation of the electrodes are described. The optimized dithenoyldiazacrown had a detection limit of pPb = 5.7, and Nernstian range with slope 29.2 mV decade⁻¹ from pPb = 5.0 to 2.7. Mercury and silver ions are the major interferences. These electrodes are applied to potentiometric titrations of lead(II) ions and show promise for the determination of lead ions in water samples.     

In vivo measurements with a potassium ion-selective microelectrode based on a new bis(crown ether)

Potassium ion-selective microelectrodes with a tip diameter of 10 μm are described. The ionophore used is 2,2′-bis[3,4-(15-crown-5)-2-nitrophenylcarbamoxymethyl] tetradecane in a conventional mixture with sodium tetraphenylborate, an ether and PVC. The electrode provides Nernstian response over the range 10^?5?10^?1 M potassium activity. Its selectivity is shown to be similar to that of a valinomycin-based microelectrode. After the electrode has aged for 24 h, the 95% response time at the 10^?3 M potassium ion level is 2.0 ± 0.5 s. The applicability of the bis(crown ether) electrode for measurements in vivo is proved by monitoring the changes in potassium activity in different areas of the brain of anaesthetized rats after administration of veratrine.     

Synthesis and properties of poly(ether imide)s based on the bis(ether anhydride)s from hydroquinone and its derivatives

Four bis(ether anhydride)s, 4,4′‐(1,4‐phenylenedioxy)diphthalic anhydride (IV), 4,4′‐(2,5‐tolylenedioxy)‐diphthalic anhydride (Me‐IV), 4,4′‐(2‐chloro‐1,4‐phenylenedioxy)diphthalic anhydride (Cl‐IV), and 4,4′‐(2,5‐biphenylenedioxy)diphthalic anhydride (Ph‐IV), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of 4‐nitrophthalonitrile with the potassium phenoxides of hydroquinone and various substituted hydroquinones such as methylhydroquinone, chlorohydroquinone, and phenylhydroquinone in N,N‐dimethylformamide, followed by alkaline hydrolysis and dehydration. Four series of poly(ether imide)s were prepared from bis(ether anhydride)s with various aromatic diamines by a classical two‐step procedure. The inherent viscosities of the intermediate poly(amic acid)s were in the range of 0.40–2.63 dL/g. Except for those derived from p‐phenylenediamine and benzidine, almost all the poly(amic acid)s could be solution‐cast and thermally converted into transparent, flexible, and tough polyimide films. Introduction of the chloro or phenyl substituent leads to a decreased crystallinity and an increased solubility of the polymers. The glass transition temperatures (T_g) of these polyimides were recorded in the range of 204–263°C. In general, the methyl‐ and chloro‐substituted polyimides exhibited relatively higher T_gs, whereas the phenyl‐substituted ones exhibited slightly lower T_gs compared to the corresponding nonsubstituted ones. Thermogravimetric analysis (TG) showed that 10% weight loss temperatures of all the polymers were above 500°C either in nitrogen or in air. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 665–675, 1999     

Novel bis (crown ether)-based potassium sensor for biological applications

Based on structure-selectivity studies on bis-benzo-crown ether derivatives, 2,2-bis[3,4-(15-crown-5)-2-nitrophenylcarbamoxymethyl]tetradecane (BME-44) was designed and synthesized. The performance characteristics of this new, highly lipophilic ionophore of the group of bis-nitrobenzo-15-crown-5 derivatives with urethane linkage when used in liquid membrane electrodes are evaluated with special regard to the requirements of biological and clinical applications. Potentiometric steady-state and flow-through dynamic data are presented to prove the sensor capabilities for clinical and physiological potassium determinations.Dedicated to Professor W. Simon on the occasion of his 60th birthday     

Sodium ion-selective membrane electrode based on a new crown ether

A sodium ion-selective PVC membrane electrode based on di(o-methoxy)stilbenzo-24-crown-8 is reported. The electrode gives a near-Nernstian response in the range 9×10^?6–1×10^?2 M sodium ion and can be used in the pH range 5–8.5. Selectivity coefficients are 1.8×10^?1 (K⁺), 2.0×10^?4 (Li⁺) 2.5×10^?2 (NH⁺₄) and about 10^?4 for Mg²⁺, Ca²⁺ and Ba²⁺.     

Synthesis,complexation, and photochemistry of benzobisthiazole-based bis(crown ether)

Benzobisthiazole-based bis(crown ether) was synthesized and its complexation with alkali and alkaline earth cations was studied. Photochemical transformations of the free ligand and its complexes with alkaline earth cations involve E,Z-photoisomerization and [2+2] photocycloaddition. Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2056–2065, September, 2005.     

Bis(crown ether)s as Na+-K+ ATPase model in a liquid membrane

A new type of bis(crown ether)s containing 15-crown-5 and monoaza-18-crown-6 actively transported Na⁺ and K⁺ in opposite directions across a dichloromethane membrane by pH control. The effect of the structure of the ion carriers on their transport abilities was examined. A key point for the molecular design of the carriers is how to give them complexing ability toward Na⁺ under acidic conditions. A proper choice of the transport conditions was found to be essential for the success of the double uphill transport.This paper is dedicated to the memory of the late Dr C. J. Pedersen.     

Heat-resistant aromatic S-triazine-containing ring-chain polymers based on bis(ether nitrile)s: Synthesis and properties

A novel series of aromatic s-triazine-containing ring-chain polymers, which typically require high pressures to produce, were prepared by the bulk polymerization of low-melting bis(ether nitrile)s (BENs) with or without the presence of terephthalonitrile (TPH) in the catalysis of ZnCl₂ under normal pressure. Four kinds of BENs were readily synthesized by the nucleophilic displacement reaction of 4-chlorobenzonitrile with commercially available aromatic bisphenols or bisphenol-like monomers. Chemical structure of the obtained BENs and their polymers was characterized by FT-IR, WAXD and elemental analysis. Conversion studies indicate that cyano concentration, mobility and reactivity are all important factors for the polymerization, while among of them the cyano reactivity plays a dominant role. The addition of a small mount of TPH is found to be effective in promoting s-triazine forming reaction of the BENs. The synthesized polymers are insoluble, and exhibit good chemical-resistant property towards strong acids and bases together with good hydrolysis-resistant property. No detectable endothermic inflection for glass transitions is observed in the DSC traces of all polymers up to 450 °C, and the polymers exhibit excellent thermal stability with decomposition temperatures for 5% mass-loss ranging from 493-540 °C. All these attracting properties make the s-triazine-containing ring-chain polymers good candidates as matrixes for high performance polymeric materials.