Um método complexométrico simples e seletivo é proposto para a determinação de tálio na presença de outros metais, pela habilidade do etanetiol em mascarar seletivamente íons tálio (III). Em solução, o tálio presente foi inicialmente complexado com um excesso conhecido de EDTA, sendo o excesso titulado com uma solução padrão de sulfato de zinco em pH 5-6 (hexamina), usando-se xilenol como indicador. Uma solução aquosa de etanetiol 0,3 % foi então adicionada para deslocar o EDTA do complexo Tl(III)-EDTA. O EDTA livre foi titulado com solução padrão de sulfato de zinco, como anteriormente. Resultados reprodutíveis e precisos foram obtidos na faixa de 3,70 mg a 74,07 mg de Tl(III), com erro relativo menor do que ± 0,44 % e um coeficiente de variação menor do que 0,27 %. A interferência de vários íons foi estudada e o método foi usado para análise de tálio em misturas de ligas sintéticas e também em complexos.A simple and selective complexometric method for the determination of thallium in presence of other metal ions is proposed based on the selective masking ability of ethanethiol towards thallium(III). Thallium present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated with standard zinc sulphate solution at pH 5-6(hexamine) using xylenol orange as the indicator. A 0.3% aqueous solution of ethanethiol is then added to displace EDTA from the Tl(III)-EDTA complex. The released EDTA is titrated with standard zinc sulphate solution as before. Reproducible and accurate results are obtained for 3.70 mg to 74.07 mg of Tl (III) with relative error less than ± 0.44% and coefficient of variation not more than 0.27%. The interference of various ions was studied and the method was used for the analysis of thallium in its synthetic alloy mixtures and also in complexes.

A simple, rapid and accurate complexometric method for the determination of palladium(II) is proposed, based on the selective masking property of thioacetamide towards palladium(II). In the presence of diverse metal ions, palladium(II) is complexed with excess of EDTA and the surplus EDTA is back titrated at pH 5-5.5 (acetic acid-sodium acetate buffer) with standard lead nitrate solution using xylenol orange as indicator. An excess of a 0.5% aqueous solution of thioacetamide is then added to displace EDTA from Pd(II)-EDTA complex. The released EDTA is titrated with the same standard lead nitrate solution as before. Reproducible and accurate results are obtained in the concentration range 0.5 mg - 17.80 mg of palladium with relative error of +/- 0.16% and coefficient of variation not exceeding 0.26%. The effect of diverse ions is studied. The method is used for the determination of palladium in its complexes, catalysts and synthetic alloy mixtures.

Acomplexometric method for the determination of mercury(II) in presence of other metal ions, based on the selective masking action of ethanethiol towards mercury( II) is described. Mercury(II) present in a given sample solution is first complexed with an excess of EDTAand the unreacted EDTAis titrated against zinc sulphate solution at pH 5-6 (hexamine buffer) using xylenol orange as the indicator. An excess of a 0.3 % solution of ethanethiol is then added to displace EDTA from the Hg(II)-EDTA complex. The released EDTAis titrated with a standard zinc sulphate solution. Reproducible and accurate results are obtained for 4-85 mg of mercury(II) with a relative error of less than +-0.46 % and coefficient of variation of not more than 0.47 %. The effects of the presence of various ions were studied. The method can be used for the analysis of mercury in its synthetic alloy mixtures and also in complexes.

p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone (CEABT) is proposed as a new, sensitive, and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium(II) in the pH range 1-2 to form a yellow-colored complex. Beer's law is obeyed in the concentration range up to 2.64 μg cm(-3). The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 0.48-2.40 μg cm(-3). The yellowish Pd(II)-reagent complex shows a maximum absorbance at 395 nm, with molar absorptivity of 4.05×10(4) dm3 mol(-1) cm(-1) and Sandell's sensitivity of the complex from Beer's data, for D=0.001, is 0.0026 μg cm(-2). The composition of the Pd(II)-CEABT reagent complex is found to be 1:2 (M-L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes, water samples, and synthetic alloy mixtures with a fair degree of accuracy.

A simple, rapid and selective complexometric method is proposed for the determination of mercury(II). Mercury(II) and other related metal ions are first complexed with an excess of EDTA and the surplus EDTA is back-titrated with a standard lead nitrate solution at pH 5.0-6.0 (hexamine buffer) using xylenol orange as an indicator. A 0.2% solution of 2-thiazolinethiol in acetone is then added to displace EDTA from the Hg(II)-EDTA complex. The released EDTA is titrated with a standard lead nitrate solution as before. Reproducible and accurate results are obtained in the range of 0.8 g l -1 -15.8 g l -1 of mercury with a relative error less than ±0.25% and a coefficient of variation (n = 6) not higher than 0.28%. The interference of various ions was studied and the method was employed for the analysis of mercury in its synthetic alloy mixtures and in complexes.

4-(N,N-diethylamino)benzaldehyde thiosemicarbazone(DEABT) is proposed as a sensitive and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium (II) in a potassium hydrogen phthalate-hydrochloric acid buffer of pH 3.0, to form a yellow complex. Beer's law is obeyed in the concentration range up to 3.60 microgmL(-1). The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 0.36 - 3.24 microg mL(-1). The yellow Pd(II)-DEABT complex shows a maximum absorbance at 408 nm, with molar absorptivity of 3.33 x 10(4) dm3 mol(-1) cm(-1) and Sandell's sensitivity of the complex from Beer's data, for D = 0.001, is 0.0032 microg cm(-2). The composition of the Pd(II)-DEABT complex is found to be 1:2 (M:L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes and model mixtures with a fair degree of accuracy.

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Complexes of nickel(II), cobalt(II), copper(II), zinc(II), and manganese(II) are derived from the ligand, (N-(3-methoxyphenyl)-2-[(2E)-3-phenylprop-2-enoyl]hydrazinecarboxamide [MPH] and structurally characterized by various physicochemical and spectral tools such as FTIR, UV-Visible, 1 H NMR, LC-Mass, P-XRD and TGA-DTC. These studies showed that the ligand coordinated to the 3d metal ions in bidentate manner. X-ray diffraction studies indicates that the Ni(II), Cu(II) and Zn(II) complexes are crystalline in nature. Degradation mechanisms, thermodynamic and kinetic parameters of the synthesized metal complexes have been evaluated. The prepared ligand and complexes were evaluated for in-vitro antioxidant DPPH assay, in which metal complexes showed excellent activity. The molecular docking analysis by using human antioxidant enzyme DTT (PDB: 3MNG) have also been evaluated. The ligand and their metal complexes were screened for their antimicrobial activities against different pathogenic bacterial and fungal species.