Studies On Anion-Selective Electrodes With Ferrocene And Schiff Base Metallic Complexes As Neutral Carriers

The recent rapid development of ion-selective electrodes with anti-Hofmeister selectivity pattern has quite properly been the subject of widespread attention and study in the fields of electrochemistry and electroanalytical chemistry. The analytical method of ion-selective electrode is direct and nondestructive, it has simple structure, simple handled, wide potentiometric response range, highly sensitive, it can rapidly determine sample continuously, so it has been applied in most departments of industry and agriculture and science technology. Design, synthsis and application of highly selective and sensitive neutral carriers are main research subjects in the ion-selective electrode studies. This thesis focuses on seeking design and synthsis of novel metallic complex and basic studies on solvent polymeric membrane(SPM) anion-selective electrodes containing the novel metallic complex. The electrodes can be applied to practice sample analysis.Part I of this thesis deals with design of neutral carrier for solvent polymeric membrane thiocyanate electrode with high selectivity.1. N,N'-bis-(biphenyl ketone)-thiosemicarbazone metallic complexes of Cu(II) and Ni(II) were synthesized. We firstly study the potentiometric response characteristics of the anion-selective PVC membrane electrode based on these metallic complexes as neutral carrier, and found that the electrode based on N,N'-bis-(biphenyl ketone)-thiosemicarbazone copper(II) complex [Cu(II)-BBKT) as neutral carrier demonstrates high selectivity towards thiocyanate ion and anti-Hofmeister selectivity sequence in following order: SCN^- > I^-≈ Sal^- > ClO₄^- > Br^- >NO₃^->NO₂^- > F^- >SO₃^2- >SO₄^2- The electrode exhibits near Nernstian potential linear range of 8.0×10^{-6 1}.0×l0^-1 mol/L with a detection limit 7.0×10^-6 mol/L and a slope of-55.2mV/decade in pH 5.0 of phosphorate buffer solution at 20℃. The response mechanism is discussed in view of the UV spectroscopy and the A.C. impedance technique. The electrode was successfully applied to the determination of thiocyanate ion in actual sample.2. 5,5-methylene-disalicylaldehyde bis(acetylacetoneethylenediimion) copper(II) were synthesized. We firstly study the potentiometric response characteristics of the anion-selective PVC membrane electrode based on these ferrocene derivatives as neutral carrier, and found that the electrode based on 5,5-methylene-disalicylaldehyde bis(acetylacetoneethylenediimion) copper(II) [Cu2(II)-MDSBAE] as neutral carrier demonstrates high selectivity towards thiocyanate ion and anti-Hofmeister selectivity sequence in following order: SOT > Sal"> Y> C1CV> NO3'> Br' > NO2' > Cl" SO32> SO42'. The electrode exhibits near Nernstian potential linear range of 1.0*10'6¹.0xl0*lmol/L with a detection limit of 8.1xlO"7mol/L and a slope of-53.6mV/decade in pH 5.0 of phosphorate buffer solution at 25 °C. The response mechanism is discussed in view of the A. C. impedance technique. The coordination number and assiociation constants of axial coordination reaction of complex Cu2(II)-MDSBAE towards SCN', Sal', V, C1O4' and NO3' were measured by means of the UV spectroscopy technique. The electrode was successfully applied to the determination of thiocyanate ion in actual sample.Part II of this thesis deals with design of neutral carrier for solvent polymeric membrane iodide electrode with high selectivity.1. unsymmetrical Schiff base complex of salicylaldehydeacetylacetoneethylenediimine metallic complexes of Hg(II) and Cu(Il) were synthesized. We firstly study the potentiometric response characteristics of the anion-selective PVC membrane electrode based on these metallic complexes as neutral carrier, and found that the electrode based on salicylaldehydeacetylacetoneethylenediimine mercury(II) complex [Hg(sal)(acac)en] has a near Nernstian potentiometric response from 2.0X10"6- 1. 0xl0"'mol/L with a detection limit 8. OxlO'7 mol/L and a slope of -55.7mV/dec in pH 2.5 of phosphate buffer solution at 25 °C. The anti-Hofmeister selectivity sequence observed is I*> Sal'> SCN'> C1O4"> Br"> F> NO3"> SO32' > NO2" > SO42\ The response mechanism is discussed in view of the UV spectroscopy technique. The electrode was successfully applied to the determination of iodide ion in actual sample.2. 2,6-Bis(hydroxymethymethyl)-4-methylphenol Glutamic acid mercury(II) and Cu(II) were synthesized. We firstly study the potentiometric response characteristics of the anion-selective PVC membrane electrode based on these metallic complexes as neutral carrier, and found that the electrode based on 2,6-Bis(hydroxymethymethyl)-4-methylphenol Glutamic acid mercury(II) complex [Hg(H)2-DFMPG] has a near Nemstian potentiometric response from 1.0X 10"' 7.0X 10"7mol/L with a detection limit 9.0x 10'7 mol/L and a slope of-53.1mV/dec in pH 2.5 of phosphate buffer solution at 25 °C. The selectivity sequence observed is I"> Sal> C1O4'> NO2" > Br'> NO3'> F> SCN"> SO32\ The response mechanism is discussed in view of the UV spectroscopy and the A.C. impedance technique. The electrode was successfully applied to the determination of iodide ion in actualsample.Part III of this thesis deals with design of neutral carrier for solvent polymeric membrane salicylate electrode with high selectivity.The mixed ligand coordination of Cu(II) with 2-[(o-hydroxybenzylidene)amino] phenol and pyridine were synthesized. We firstly study the potentiometric response characteristics of the anion-selective PVC membrane electrode based on these metallic complexes as neutral carrier, and found that the electrode based on The mixed ligand coordination of Cu(II) with 2-[(o-hydroxybenzylidene)amino] phenol and pyridine [Cu(II)-HBAPP] as neutral carrier demonstrates high selectivity towards salicylate ion and anti-Hofmeister selectivity sequence in following order: Sal'> C1O4'> SCN'> I*> NO2> NO3 = Br> Cl> SO32\ The electrode exhibits near Nernstian potential linear range of 9.2X10"6- l.OxlO'1 mol/L with a detection limit 8.0xl0"6 mol/L and a slope of -53.9 mV/dec in pH 5.0 of phosphorate buffer solution at 25°C. The response mechanism is discussed in view of the UV spectroscopy technique. The electrode was successfully applied to the determination of salicylate ion in actual sample.