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.     

含嘧啶环的双冠醚 V.双冠醚为载体的碱金属离子选择性电极的研究

本文报道由５－硝基－６－三氟甲基嘧啶环桥联苯并－１２－冠－４、苯并－１５－冠－５和苯并－１８－冠－６的三种新的双冠醚的合成。用它们作为载体分别制成钠、钾和铯离子选择性电极，测定了电极的响应功能、选择性系数和适用的ｐＨ范围。结果表明三种电极都有较好的性能。     

含嘧啶环的双冠醚(Ⅳ)

前文已报道由啶环桥联两个苯并冠醚的双冠醚的合成与性质。由于嘧啶环的刚性较大,能把两个冠醚单元固定在有效地协同作用位置,因此以它们作中性载体的离子选择性电极具有较好的选择性。为了进一步研究这类双冠醚的性质,我们合成了四种嘧啶环桥联两个脂肪族冠醚的双冠醚,并经元素分析、IR、′HNMR鉴定。     

Cation selectivity of 13-crown-4 and bis(13-crown-4) derivatives

The cation selectivity of liquid-membrane electrodes based on 18 derivatives of 13- crown-4 and bis(13-crown-4) is reported. When these compounds are dissolved in 1,2-dichlorobenzene, the electrodes exhibit MgCl⁺ selectivity which depends on the nature of the bonds connecting the crown ether rings.     

Bis(2-mercaptobenzoxazolato)mercury(II) and bis(2-pyridinethiolato)mercury(II) complexes as carriers for thiocyanate selective electrodes

Highly selective poly(vinyl chloride) (PVC) membrane electrodes based on bis(2-mercaptobenzoxazolato)mercury(II) [Hg(MBO)₂] and bis(2-pyridinethiolato)mercury(II) [Hg(PT)₂] complexes as new carriers for thiocyanate-selective electrodes are reported. The electrodes were prepared by coating the membrane solution containing PVC, plasticizer, carriers and additives on the surface of graphite electrodes. Influence of the membrane composition, pH and possible interfering anions were investigated on the response properties of the electrodes. Both sensors exhibited Nernstian responses towards thiocyanate over a wide concentration range of 1×10⁻⁶ to 0.1 M, with slopes of 60.6±0.8 and 57.5±1.2 mV per decade of thiocyanate concentration for Hg(MBO)₂ and Hg(PT)₂ carriers, respectively, over a wide pH range of 3-11. The limit of detection for both electrodes was ∼6×10⁻⁷ M. The sensors have response times of ≤5 s and can be used for at least 2 months without any considerable divergence in their potential response. The proposed electrodes show fairly good discrimination of thiocyanate over several inorganic and organic anions. The electrodes were successfully applied to direct determination of thiocyanate in saliva and as indicator electrodes in precipitation titrations.     

Hyamine 1622 - Selective PVC Membrane Electrodes Based on bis (Crown Ether)s

Abstract

Hyamine 1622 - selective PVC membrane electrodes based on bis (crown ether)s containing the benzo - 18 - crown - 6 moiety were prepared, using o - nitrophenyloctylether (NPOE) or dipentylphthalate (DPP) as the plasticizer of the PVC membrane. Selectivity coefficients for various interfering ions (inorganic and organic cations), were determined by the mixed solution method. The selectivity of the respective electrodes was found to be affected by the kind of plasticizer employed, and NPOE seemed to be a more suitable plasticizer than DPP. The NPOE electrode system based on the bis (crown ether) that has 11 atoms between the two benzo-18-crown-6 moieties offers the advantage of greater selectivity. The electrodes show excellent electrode properties, and the electrode response was stable in a wide pH range.     

Supramolecular Immobilization of Laccase on Carbon Nanotube Electrodes Functionalized with (Methylpyrenylaminomethyl)anthraquinone for Direct Electron Reduction of Oxygen

An efficient way of immobilizing and wiring a large amount of laccase on non‐covalently‐functionalized multi‐walled carbon nanotube (MWCNT) electrodes is reported. 1‐(2‐anthraquinonylaminomethyl)pyrene and 1‐[bis(2‐anthraquinonyl)aminomethyl]pyrene were synthesized and studied for their capability to non‐covalently functionalize MWCNT electrodes and immobilize and orientate laccase on the nanostructured electrodes. This led to high‐performance biocathodes for oxygen reduction by direct electron transfer with maximum current densities of (1±0.2) mA cm^?2. The performance of the resulting bioelectrodes could be doubled simply by using the bis‐anthraquinone compound. The bioelectrodes show excellent stability over weeks and can thus be envisioned in enzymatic biofuel cells.     

Thermodynamics,a suitable reporter in the design of mercury (II) ion selective electrodes

A fully functionalised calix[4]pyrrole derivative, namely, meso-tetramethyl-tetrakis[(diethylthiocarbamoyl)phenoxy] calix[4]-pyrrole, 1 has been synthesised and structurally characterised. Its complexing properties with metal cations in acetonitrile were investigated with particular emphasis on the thermodynamics of these systems. These data and those previously reported for a partially functionalised calix[4]arene based receptor, 5,11,17,23-tetra-tert-butyl[25,27 bis(diethylthiocarbamoyl)oxy]calix[4]arene, 2 were used to, i) further corroborate their use to predict the selectivity coefficients of carrier mediated mercury (II) ion selective electrodes (ISEs) and ii) to obtain approximate stability constant data from selectivity coefficients. The optimum working conditions of both electrodes were determined. It is shown that while the ISE based on 1 is characterised by a wider linear range and a lower mercury (II) detection than the one based on 2, the latter has the advantage of lower interference of other metal cations due to the much lower stability constants of bivalent cations relative to Hg(II). The response characteristics of these electrodes are compared with those found in the literature. SEM micrographs along with EDX spectra of the PVC membranes containing ionophore 1 or 2 unloaded and loaded with Hg(II) are reported.     

Capacitance response of carbons in solvent-free ionic liquid electrolytes

Ionic liquids (IL) are very promising “solvent-free” electrolytes for high-voltage double-layer supercapacitors (EDLCs) and to this purpose they are generally selected on the basis of their bulk properties, such as electrochemical stability and ion conductivity, without taking into account those of the electrified electrode-IL interface. This interface, which has yet to be well characterized, has features that notably affect electrode capacitance, and our paper for the first time highlights the importance of the molecular chemistry and structure of the ions for the double-layer capacitive response of carbonaceous electrodes in IL. The double-layer capacitive responses of negatively charged electrodes based on activated carbons and aero/cryo/xerogel carbons in two ILs featuring the same anion and different cations of almost the same size, i.e. the N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR₁₄TFSI) and 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI) are reported. The porosity, structure and surface chemistry of the carbons are compared to their capacitive response to evince the role played by these carbon properties and by the chemistry and structure of the IL ions in the electric double-layer.     

Combining Fullerenes and Zwitterions in Non‐Conjugated Polymer Interlayers to Raise Solar Cell Efficiency

Polymer zwitterions were synthesized by nucleophilic ring‐opening of 3,3′‐(but‐2‐ene‐1,4‐diyl)bis(1,2‐oxathiolane 2,2‐dioxide) (a bis‐sultone) with functional perylene diimide (PDI) or fullerene monomers. Integration of these polymers into solar cell devices as cathode interlayers boosted efficiencies of fullerene‐based organic photovoltaics (OPVs) from 2.75 % to 10.74 %, and of non‐fullerene‐based OPVs from 4.25 % to 10.10 %, demonstrating the versatility of these interlayer materials in OPVs. The fullerene‐containing polymer zwitterion ( C₆₀‐PZ ) showed a higher interfacial dipole (Δ) value and electron mobility than its PDI counterpart ( PDI‐PZ ), affording solar cells with high efficiency. The power of PDI‐PZ and C₆₀‐PZ to improve electron injection and extraction processes when positioned between metal electrodes and organic semiconductors highlights their promise to overcome energy barriers at the hard‐soft materials interface of organic electronics.     

Electrocatalytic properties of guanine, adenine, guanosine-5'-monophosphate, and ssDNA by Fe(II) bis(2,2':6',2'-terpyridine), Fe(II) tris(1,10-phenanthroline), and poly-Fe(II) tris(5-amino-1,10-phenanthroline)

The electrocatalytic oxidations of guanine, adenine, guanosine-5'-monophosphate(GMP) and ssDNA were performed in the presence of Fe(II) bis(2,2':6',2'-terpyridine) and Fe(II) tris(1,10-phenanthroline) complexes as homogeneous catalysts by cyclic voltammetric methods. The Fe(II/III) redox couple of these compounds is responsible for their catalytic properties. The electrocatalytic oxidation current of above substrates were developed from the anodic peak currents of Fe(II) bis(2,2':6',2'-terpyridine) and Fe(II) tris(1,10-phenanthroline) complexes at about +0.93 V and 0.97 V, respectively. The electrocatalytic oxidative properties of guanine by Fe(II) bis(2,2':6',2'-terpyridine) complex was measured by amperometry method using the rotating disk electrodes. Electropolymerization of Fe(II) tris(5-amino-1,10-phenanthroline) complex produced thin polymer films on gold and glassy carbon electrodes. The electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry were used to study the in situ growth of the polymer. The poly(FeII(5-NH(2)-1,10-phen)(3)) exhibited a good electrocatalytic oxidation towards guanine and also for the mixture of guanine and adenine too.     

Electrochemical behavior of activated carbon electrodes in electric double layer capacitors with tetrametylammonium bis(oxalato)borate electrolyte synthesized by microwave irradiation

The electrochemical behavior of electric double layer capacitors (EDLCs) with tetramethylammonium bis(oxalato)borate electrolyte and electrodes based on various activated carbons (ACs) was studied. Tetraalkylammonium bis(oxalate)borate salts were synthesized by means of microwave (MW) irradiation. The specific conductivities of salt solutions were determined. It was shown that the efficiency of electric double layer capacitors increases with an increase in specific surface area and a decrease in the purity of carbon materials.     

An evaluation of solvent mediators for ion-selective electrode membranes based on calcium bis(dialkylphosphate) sensors trapped in poly(vinyl chloride) matrices

This study on several alkan-1-ols, di-n-octylphenyl phosphorate and di-n-nonyl phthalate as solvent materials in ion-selective electrode membranes based on calcium bis(dialkylphosphate) sensors trapped in a PVC matrix indicates that the best electrodes are made with di-n-octylphenyl phosphonate. These are selective for calcium. The liquid alcohols readily exude from the PVC matrix, and solid alcohols are completely unsuitable for membrane fabrication. However, despite a tendency to be exuded, decan-1-ol gives acceptable electrodes responsive to bivalent cations if calcium bis (di-2-ethylhexylphosphate) is used as sensor. Several selectivity coefficients, k(caj), greater than unity were found, but though such values for j = Na or K do not involve complete loss of selectivity towards calcium, a value of K(CaCu) = 13 for a membrane with di-n-nonyl phthalate as mediator and calcium bis(di-n-decylphosphate) as sensor indicates greater selectivity for copper than for calcium.     

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.     

Ion-selective electrode studies on novel organic molecule sensors.

Researches on prospects for novel ion-selective electrodes, based on organic molecule sensors, are described. The organic molecules are large crown ethers extending from bis(metaphenylene)-26-crown-8 to bis(metaphenylene)-38-crown-12, small crown ethers, bis-crown ethers, and acyclic polyethers consisting of diphenyl ethers of tetraethylene glycol and receptor molecules of planar and tetrahedral tripodal types.     

冠醚载体离子电极的选择特性研究

阴离子选择电极选择性系数随干扰离子r_j/z_j的变化规律已有报道,但冠醚为中性载体的金属离子电极的选择性系数规律未见报道。本文采用不同桥间结构的11种苯并双冠醚作为中性载体,从钾电极出发探讨了不同冠醚电极选择性系数与干扰离子r_j/z_j间的关系;并以4种烃型双冠醚为中性载体,分别考察了它们对Li~+、Rb~+、Cs~+、Ag~+、Ba~(2+)离子的响应规律。 1 实验部分     

Reversible electrochemical oxidation of (CH)x films

Thallium(I)-selective PVC membrane electrodes based on bis(crown ether)s containing benzo-15-crown-5 moiety were prepared, using o-nitrophenyloctylether(NPOE) or dipentylphthalate(DPP) as the plasticizer of the PVC membrane. Selectivity coefficients for various alkali and alkaline earth metal ions, k_TIM, were sufficiently small, and were compared with those of the corresponding monocyclic analog and valinomycin. These electrodes show excellent electrode properties, and the electrode response was stable in a wide pH range.     

Calcium‐Selective Electrodes for Measurements in the Presence of Anionic Surfactants

Calcium selective electrodes with various membrane formulations were studied in solutions containing CaCl₂ and sodium dodecylsulfate (NaDS). It is shown that electrodes based on neutral ionophores ETH 1001 and ETH 129 cannot be used as Ca²⁺ ion sensors in these solutions because of strong anion interference from DS^? anion. Among other formulations, that based on calcium bis(tetramethylbutylphenyl)phosphate in tri(2‐ethylhexyl)phosphate appear the most promising. The interpretation of the ISE response in solutions under study relied on a novel approach which considers three forms of calcium: Ca²⁺ free ions, Ca in Ca(DS)₂ precipitate, and Ca²⁺ bound by the DS^? micelles. Data needed for the respective calculations were obtained by DS^? selective electrode based on tetradecylammonium, and Na⁺ selective glass electrode.     

Anion-selective electrodes based on ionic liquid membranes: effect of ionic liquid anion on observed response

A systematic study of the behavior of ion-exchanger anion-selective electrodes prepared from seven different trihexyltetradecylphosphonium ionic liquids (ILs) was performed. The effective ion-exchange capacity of prepared ion-selective electrodes (ISEs) increased with decreasing IL anion lipophilicity, and analyte anion response slopes became more Nernstian concomitantly. With ILs having the most lipophilic constituent anions, incorporation of tridodecylmethylammonium chloride into membranes significantly enhanced responses toward all ions. However, ILs based on bis(trifluoromethylsulfonyl)imide and dodecylsulfate maintained sub-Nernstian responses upon such addition apparently due to their ability to coordinate cations. Electrodes prepared with high IL content displayed regions of super-Nernstian response, which could be eliminated by reducing percent of IL in the membrane; percentages at which optimal linear range was achieved also followed a trend with decreasing constituent IL anion lipophilicity. While selectivities of all electrodes followed the Hofmeister pattern, selectivity coefficient ranges generally were narrower than observed with traditionally plasticized ISEs, and selectivities for more hydrophilic analytes were improved slightly in ILs containing the most hydrophilic constituent anions.     

LiTFSI/2-噁唑烷酮电解液与不同微结构碳材料的电化学兼容性

二（三氟甲基磺酸酰）亚胺锂（LiTFSI）与1,3-氮氧杂环戊-2-酮（OZO）形成的离子液体具有良好的物理和电化学性能,表现出宽的液相温度范围和高的离子电导率,可满足超级电容器的应用需求。本文制备的LiTFSI-OZO离子液体体系中,各种离子的结构组成（如自由离子、离子对、积聚离子）及其之间的相互作用对离子液体的电化学性能具有较大的影响,将其作为电解液应用于不同微结构特性（孔径、比表面积等）的炭材料（碳纳米管(CNTs)、中孔活性炭(MEACs)和微孔活性炭(MIACs)）作为电极的电化学双层电容器中,电化学兼容性研究表明,由于中孔活性炭电极材料有最大的比表面积及最适宜的孔径分布,相应的模拟电容具有最高的比容量184.6 F?g-1。该研究表明,对电极材料的微结构特性与离子液体离子尺度进行优化匹配是实现离子液体作为电解液应用于超级电容器的关键。