基于杂环有机锡化合物的水杨酸根离子选择电极研究

A novel heterocyclic haxacoordinated organotin(Ⅳ) complex, bis (o-vanillin)-semi-ethylenediamine dibenzyltin (VEDBT) was synthesized and used as anion ionophore for PVC membrane electrode; the novel electrode exhibits a linear response towards salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions, the selective pattern is: Sal^- > SCN^- > ClO₄^- > I^- > NO₂^- > NO₃^- > Cl^- ≈ Br^- > SO₄^2-. The behaviour of the electrode is influenced by the experimental conditions. The response mechanism was also investigated by UV spectroscopy. The electrode was applied to the determination of salicylate in pharmaceutical samples with satisfactory results.     

有机体系中纳米TiO2 / ZrO2修饰电极的制备及电催化活性

The complexes Ti(OCH₂CH₂O)₂ and Zr(OCH₂CH₂O)₂ were directly synthesized by using HOCH₂CH₂OH dissolution in 50 mL flask. The nano-ZrO₂ / TiO₂ powders were prepared by a direct sol-gel synthesis using the above solution and followed by drying at 400 ℃ for 2 h. The complexes were characterized by FTIR and ¹H NMR. XRD and TEM were used to investigate the structure of nano-ZrO₂ / TiO₂. The results show that the complexes containing ^-OCH₂CH₂O^- group could prevent the precursor from agglomeration and sintering during the hydrolysis and calcination process. The ZrO₂ / TiO₂ powders of 20～35 nm was thus obtained in a high purity. The highly active nano-ZrO₂ / TiO₂ modified electrode was prepared by using daubing and calcination. The electro-catalytic activities of this electrode in (COOH)₂ were investigated. The discharge current of nano-ZrO₂ / TiO₂ electrode increased obviously. In preparative electrolysis under optimal conditions, the average yield and current efficiency for HOOC-CHO were 84.7% and 91.6 %, respectively.     

不同稀土改性SO42-/ZrO2催化剂的结构与性能表征

Solid superacid catalyst SO₄^2-/ZrO₂ was modified by different rare earth compounds and applied to the esterification of acetic acid and n-butanol. The effects of rare earth elements loading on the catalytic properties were studied and the correlation between the structure and properties was investigated by means of XRD, IR, UV, DTA and TG. The results show that the (NH₄)₂Ce(NO₃)₆ modification can enhance catalytic activity more and exhibit better stability than the other two compounds La(NO₃)₃ and Ce(NO₃)₃. Meanwhile,(NH₄)₂Ce(NO₃)₆ modification can restrain the loss of SO₄^2- efficiently. The optimum calcination temperature and molar ratio of Ce(NH)∶Zr for SO₄^2-/ZrO₂ catalyst modified by (NH₄)₂Ce(NO₃)₆ are 450 ℃ and 2, respectively.     

α-十四烷基-DOTA及其钆(Ⅲ)螯合物的合成与表征(英)

Synthesis and characterization of the ligand, [10-(α-tetradecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, H₄L] and its Gd(Ⅲ) chelate are described. Protonation constants for H₄L(lgK_i^H = 10.62, 9.50, 4.74, 4.12) and the stability constant for GdL^-(lgK_GdL^-= 24.60) were determined by potentiometric titrations. The results obtained show that the basicity of the ligand is not significantly altered and the ligand still maintains the strong chelating properties of the parent DOTA after introduction of a linear chain tetradecyl group at the acetic side chain of DOTA.     

金刚烷胺邻香兰素Schiff碱稀土配合物的合成、表征及抗菌活性研究

The new solid complexes [LnL₂(NO₃)₂]NO₃ (L=C₁₈H₂₃NO₂, N-2-hydroxy-3-methoxy-benzaldehyde-1-aminoadamanantane, Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y) of rare earth nitrates with Schiff base derived from o-vanillin and adamantaneamine have been synthesized in non-aqueous system and characterized by elemental analysis, molar conductance, infrared spectra, ¹H NMR spectra, thermal analysis. The coordination modes of the bonding in these complexes were discussed and the possible structure were proposed. Every central Ln(Ⅲ) ion in the complexes coordinates with both two Schiff base ligands via four oxygen atoms of the phenol hydroxy groups and methoxy groups and two nitrates via their four oxygen atoms. Their coordination numbers are eight. In addition, the antibacterial activity of the Schiff base ligand and the complexes were studied.     

2-十四烷基-DTPA及其钆(Ⅲ)螯合物的合成与表征(英)

Synthesis and characterization of the ligand, [2-tetradecyl-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecan-1,11-dioic acid, H₅L] and its Gd(Ⅲ) chelate are described. Protonation constants for H₅L (lgK_i^H = 10.80, 8.40, 4.30, 2.80, 2.15) and the stability constant for GdL^2- (lgK_GdL^2-= 22.75) were determined by potentiometric titration and are similar with the related values of DTPA and Gd-DTPA respectively. The results obtained show that the basicity of the ligand and the stability constant of its Gd(Ⅲ) chelate are not obviously altered after introduction of a linear chain tetradecyl group at the terminal acetic acid residue of DTPA.     

铜取代Dawson结构杂多钨磷酸电荷转移配合物的合成与性质研究

Two new charge-transfer complexes, (DMAH)₁₀［CuP₂W₁₇O₆₂］·DMF·2H₂O and (DMAH)₁₄［Cu₂P₂W₁₆O₆₂］ have been prepared in aqueous solution from N,N′-dimethylaniline(DMA) and copper substituted polyoxotungstates with Dawson Structure, and characterized by elemental analysis, ICP, TG, IR, diffusion reflectance electronic spectra, polarography, and CV. The results indicate that the structure of anion has little change after the charge-transfer complexes are formed, but the characteristic vibrational bands have some red shift or blue shift. The charge transfer takes place under sunlight. There is a new absorption band at 625 nm in the solid reflectance electronic spectra of the complexes, it is ascribed to the IVCT (W(V)→W(Ⅵ) band of the reduced anion ［CuP₂W₁₇O₆₂］^10-. The conductivities at room temperature of title complexes are 3.6×10^-9 S·cm^-1 and 5.4×10^-9 S·cm^-1, respectively. Both of them are weak semiconductors.     

Keggin结构过渡金属杂多阴离子中配位水与奎宁的取代反应

The substitution reaction of quinine by the 18 types of heteropoly complexes, for these formed compounds are Keggin structure and the molecular formulas are [XM₁₁O₃₉M′(OH)₂]^6-(X=Si,Ge,P;M=Mo or W;M′=Co,Ni,Cu), was studied by the means of phase transfer. The results of characterization that were accomplished by UV and ESR indicated that the quinine does form the chemical bond with the hetropoly ligands. Spectral experiment demonstrated that the structure held the same when the heteropoly complex contained Cu²⁺ was reacted with qui-nine, while the heteropoly complex contained Ni²⁺ resulted in the changing of the structure. Such a result of op-tical rotatory opticity testified that quinine reacting with heteropoly acid contained transitional metals could form a kind of new complexes which were optical rotation.     

三元稀土配合物RE(NTA)2AA的合成、共聚反应性及荧光性能研究

Four new ternary rare earth complexes RE(NTA)₂AA (RE=Sm³⁺， Eu³⁺， Tb³⁺， Dy³⁺) have been synthesized by the reaction of rare earth chloride(RECl₃·6H₂O) with Acrylic Acid (HAA) and 4，4，4-trifluoro-1-(3-pyridyl)-1，3-butanedione(NTA) in alcohol. The copolymerization of the complexes RE(NTA)₂AA (RE=Sm³⁺， Eu³⁺) with methyl methacrylate (MMA) has been studied by 2， 2-azobis-isobutyronitrile as an initiator. Influence of adding Eu(Ⅲ) and 2，2′-bipyridine(bipy) into copolymer Eu(NTA)₂AA-co-MMA on fluorescence property of the Eu copolymer was investigated. The compositions of the complexes and copolymer were characterized by means of elemental analysis and FTIR. The heat decomposing behaviors of the complexes were determined by TG-DTA. The glass transition temperature and molecular weight were obtained by DSC and GPC. The results of fluorescence properties show that the Eu， Sm complexes and Eu copolymer can efficiently emit fluorescence， but the Tb and Dy complexes only emit the fluorescence of β-diketone ligand.     

Potentiometric sensor for sensitive and selective detection of heparin

A polymeric membrane ion-selective electrode for determination of heparin is described in this paper.Protamine is incorporated into the organic membrane phase and functions as sensing element for selective recognition of heparin.The proposed membrane electrode exhibits high selectivity for heparin over lipophilic anions such as thiocyanide and salicylate.The potentiometric response to the concentration of heparin is Unear in the range of 0.01-0.4 U/mL and a lower detection limit of 0.005 U/mL can be achieved.     

有机锡化合物结构与电极性能的构效关系研究

系统研究了三类有机锡化合物的阴离子响应行为。结果表明,有机锡化合物的结构与电极响应行为之间呈现出非常密切的构效关系。三类有机锡化合物对水杨酸根离子均呈现出选择性的电位响应性能,其中四配位有机锡化合物对水杨酸根离子呈现近nernst响应,而五、六配位有机锡化合物对水杨酸根离子均呈现超nernst响应。更重要的是,载体中心原子上正电荷密度对电极响应性能有很大影响。随着与锡原子相连的有机基团性质的变化,载体对水杨酸根离子的电位响应性能和选择性均发生规律性的变化,通过hammett常数定性地描述了载体结构与电极性能的构效关系。同时,通过交流阻抗、膜红外光谱等技术对电极响应机制作了初步探讨,并对超nernst现象和六配位有机锡化合物的响应行为进行了解释。     

Pentacoordinate organotin complexes as neutral carriers for salicylate-selective PVC membrane electrodes

Selectivity properties are established for three new electrodes prepared by incorporating three pentacoordinate organotin(IV) complexes, mono(2,4-pentanedionato-o,o') tri(phenylmethyl)tin (DMTBS), mono(benzoylacetonato-o,o') tri(phenylmethyl)tin (MPTBS) and mono(dibenzoylmethanato-o,o') tri(phenylmethyl)tin (DPTBS) into plasticized PVC membranes. These electrodes exhibit linear response to salicylate and an anti-Hofmeister selectivity pattern with high specificity for salicylate over many common anions. The results show that the potentiometric response characteristics are related to the structure of organic ligands. The detection limit and the slope of the electrodes based on these pentacoordinate organotin complexes exhibit a tendency to decrease as the substituent in organic ligands changes from a methyl group to a phenyl group. Electrodes prepared with DMTBS have the best detection limit and the highest degree of selectivity and sensitivity for salicylate. The response mechanism is also investigated by use of a.c. impedance and i.r. spectroscopic techniques.     

Potentiometric membrane electrode for salicylate based on an organotin complex with a salicylal Schiff base of amino acid.

A novel salicylate-selective electrode based on an organotin complex with a salicylal Schiff base of amino acid salicylaldehydeaminoacid-di-n-butyl-Sn(IV) [Sn(IV)-SAADB] as ionophore is described, which exhibits high selectivity for salicylate over many other common anions with an anti-Hofmeister selectivity sequence: Sal- > PhCOO- > SCN- > Cl04- > I- > NO3- > NO2- > Br- > Cl- > CH3COO-. The electrode, based on Sn(IV)-SAADB, with a 30.44 wt% PVC, a 65.45 wt% plasticizer (dioctyl phthalate, DOP), a 3.81 wt% ionophore and a 0.3 wt% anionic additive is linear in 6.0 x 10(-6) - 1.0 x 10(-1) mol l(-1) with a detection limit of 2.0 x 10(-6) mol l(-1) and a slope of 62.0 +/- 1.2 mV/decade of salicylate concentration in a phosphate buffer solution of pH 5.5 at 25 degrees C. The influence on the electrode performances by lipophilic charged additives was studied, and the possible response mechanism was investigated by UV spectra. The electrode was applied to medicine analysis and the result obtained has been satisfactory.     

Salicylate-selective electrode based on lipophilic tin(IV)phthalocyanine

A new PVC membrane electrode based on lipophilic (2,9,16,23-tetra-tert-butylphthalocyanine)tin(IV) dichloride which demonstrates excellent selectivity and fast response toward the salicylate ion is described. The membrane electrode displayed a linear response for salicylate in the concentration range 10(-5)-0.1 M and exhibited an antiHofmeister pattern, with high selectivity for salicylate compared with lipophilic inorganic and biologically important organic anions. The electrode was successfully applied to the determination of salicylate in pharmaceutical preparations and biological samples.     

杂环苄基锡氨基硫脲席夫碱配合物的合成与表征

二苄基二氯化锡和三苄基氯化锡分别与水杨醛缩氨基硫脲,含羟基芳香醛(酮)缩氨基硫脲的席夫碱钠盐反应,合成了10种新的有机锡配合物,其结构经1H NMR,119Sn NMR,IR和元素分析表征。结果表明,中心锡原子均为五配位杂单环结构。     

Salicylate ion-selective electrode based on new tetranuclear copper complexes of O-vannlin-methionine as neutral carriers.

A new salicylate-selective PVC membrane electrode based on a new Schiff base tetranuclear copper complex of O-vannlin-methionine (Cu(II)(4)-TVM) as a neutral carrier is described. This electrode displays a preferential potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal(-) > ClO(4)(-) > SCN(-) > I(-) > NO(2)(-) > NO(3)(-) > Br(-) > Cl(-) > SO(3)(2-) > SO(4)(2-) > H(2)PO(4)(-). The electrode exhibits near-Nernstian potential linear range of 1.5 x 10(-6)-1.0 x 10(-1) M with a detection limit of 8.0 x 10(-7) M and a slope of -56.3 mV/decade in pH 3.0-8.0 of phosphorate buffer solution at 20 degrees C. Thanks to the tetranuclear copper(II) in the carrier, the electrode has the advantages of simplicity, fast response, fair stability and reproducibility and low detection limit. The response mechanism to the electrodes is discussed by the a.c. impedance technique and the UV spectroscopy technique. The electrode can be applied to analyses of medicine and the results obtained are in fair agreement with the results given by a standard method.     

A novel ethacrynic acid sensor based on a lanthanide porphyrin complex in a PVC matrix

Lanthanide porphyrin complexes synthesized by a solid state method were used to prepare a novel ethacrynic acid (EA) sensor. The sensor, based on pentane-2,4-dionato(meso-tetraphenylporphinato)terbium [TbTPP(acac)] with an optimized membrane composition, exhibits a Nernstian response to EA- ion in the concentration range 7.4 x 10(-6)-1.0 x 10(-1) mol l-1 with a pH range from 3.2 to 6.8 and a fast response time of 30 s. The electrode shows improved selectivity towards EA- ion with respect to common co-existing ions compared with the previously reported EA sensor. As electroactive materials, lanthanide porphyrin complexes show better potentiometric response characteristics than copper porphyrin complexes. The effect of solvent mediators and lipophilic ion additives was studied and the experimental conditions were optimized. The electrode was applied to the determination of EA in human urine samples with satisfactory results.     

Anion selective polymeric membrane electrodes based on cyclopalladated amine complexes

The potentiometric anion selectivity of two polymer membrane based electrodes (I and II) formulated with two new cyclopalladated amine complexes as the active components are examined. The electrodes exhibit a non-Hofmeister selectivity pattern with a significantly enhanced response towards thiocyanate, iodide and nitrite. The graph potential versus log c is linear over the concentration range 10(-6)-6x10(-2) M thiocyanate with electrode I and 10(-6)-10(-3) M with electrode II; 10(-5)-10(-2) M iodide with electrode I and 10(-3)-6x10(-2) M with electrode II; and 10(-3)-6x10(-2) M nitrite with both electrodes. The influence of the plasticizer and pH are studied. The potentiometric selectivity coefficients for I, II and blank membrane electrodes are reported. The selective interaction between Pd(II) thiocyanate, iodide and nitrite is postulated to be the reason for its higher response.     

A novel salicylate-selective electrode based on a Sn(IV) complex of salicylal-imino acid Schiff base

A novel poly(vinyl chloride) membrane electrode with high selectivity toward salicylate (Sal^–), based on the use of the salicylal-imino acid Schiff base dibenyl complex of Sn(IV) [Sn(IV)-SIADBen] as ionophore is described. The influence of lipophilic charged additives on the performance of the electrode was studied. The results suggested that Sn(IV)-SIADBen according to a positively-charged carrier mechanism. The influence of several other variables was investigated in order to optimize the potentiometric response and selectivity of the electrode. The electrode based on Sn(IV)-SIADBen, with 30.44 wt% PVC, 64.55 wt% plasticizer [dioctyl phthalate (DOP)], 3.81 wt% ionophore, and 1.2 wt% anionic additive exhibited a linear response for the Sal^– ion over the concentration range 1.0×10^–1 to 2.5×10^–6 mol l^–1, and displayed an anti-Hofmeister selectivity sequence as follows: salicylate perchlorate > thiocyanate > benzoate > iodide > nitrate > chloride > nitrite acetate > citrate > sulfate. UV-Visible absorption spectra were used to examine the specific interaction of salicylate with the ionophore. The electrode was applied to clinical medical analysis, and the results obtained were consistent with those obtained by conventional methods.     

Binuclear Schiff base complex of manganese(III) as a neutral carrier for a highly selective iodide electrode.

A new highly selective iodide electrode incorporating a binuclear manganese(III) complex, bis(salicylaldehyde-aminopropanol)dichloroaceticdimanganese(III) [Mn(III)(2)-BSAPDCA], as a neutral carrier is described. The electrode displays an anti-Hofmeister selectivity sequence: iodide > perchlorate > salicylate > thiocyanate > nitrate > bromide > nitrite > chloride > sulfate. The excellent selectivity for iodide is related to a direct interaction between the central Mn(III) atom and iodide and a steric effect associated with the structure of the carrier, which is supported by UV spectroscopy and AC impedance techniques. The electrode exhibits a near-Nernstian potentiometric linear response range to iodide from 1.0 x 10(-1) to 2.0 x 10(-5) mol/L with a detection limit of 8.0 x 10(-6) mol/L and a slope of -60.3 mV/decade in pH 3.0 of phosphate buffer solutions at 20 degrees C. From a comparison of the potentiometric response characteristics between a binuclear manganese(III) complex, Mn(III)(2)-BSAPDCA, and a mononuclear manganese(III) complex, Mn(III)-BSAPB, an enhanced response towards iodide from a binuclear metallic complex-based electrode was observed. The electrode, based on binuclear manganese(III) complex, was successfully applied to the determination of inorganic total iodine in iodized table salt with satisfactory results.