D. Venkata Reddy

Spectrophotometric determination of palladium with 5,6-dimethyl-1,3-indanedione-2-oxime.

A rapid, sensitive and selective method has been developed for the determination of palladium with 5,6-dimethyl-1,3-indanedione-2-oxime in acetate buffer (pH 5.5). Beers law is obeyed over the range 0.15-4.17 mug/ml palladium(II). The molar absorptivity at 370 nm is 2.98 x 10(4) 1.mole(-1).cm(-1). The method has been applied for the determination of palladium in synthetic mixtures corresponding to PtIr and Oakay alloys. An interesting feature of the system is the abnormal shape of the Job and molar-ratio plots obtained.

Anisaldehyde-4-phenyl-3-thiosemicarbazone as an analytical reagent for the extractive spectrophotometric determination of gold

The synthesis, spectral characteristics and analytical applications of anisaldehyde-4-phenyl-3-thiosemicarbazone (APT) are described. A simple, rapid, selective and sensitive spectrophotometric method for the determination of microgram amounts of gold, alone or in the presence of associated metals, is developed, based on the colour reaction between the metal ion and anisaldehyde-4-phenyl-3-thiosemicarbazone. The yellow-brown complex (λmax.= 365 nm) is extracted into ethyl acetate. Gold(III) reacts with the reagent in the ratio 1 : 1 (metal to ligand) over the pH range 4.0–7.0. Beers law is obeyed over the concentration range 0.1–12.3 µg ml–1 of gold. The molar absorptivity and Sandells sensitivity of the method are 2.12 × 104 l mol–1 cm–1 and 0.0092 µg cm–2, respectively. The relative standard deviation for ten replicate determinations of 45 µg of gold(III) was 1.71%. The interference of various ions has been studied and conditions were developed for the determination of gold in some synthetic samples.

Rapid Spectrophotometric Determination Of Osmium With Cyclohezane 1,3-Dione Bisthiosemicarbazone Monohydrochloride: Simultaneous Determination of Osmium and Platinum

Abstract A simple, sensitive and rapid spectrophotometric method has been developed for the determination of osmium using cyclohexane 1,3-dione bisthiosemicarbazone mono-hydrochloride (1,3-CHDT.HCl). The method is based on the instantaneous colour reaction between 1,3-CHDT. HCl and osmium(VIII) in sodium acetate—acetic acid buffer medium (pH range 3–6). The osmium complex shows maximum absorbance at 375 nm and considerable absorbance at 510 nm. Although the complex formed between platinum(IV) and reagent (1,3-CHDT.HCl) shows maximum absorbance at 375 nm, it does not show any absorbance at 510 nm. Simultaneous determination of osmium and platinum is carried out when present alone and in presence of other foreign (associated) ions. Some physico-chemical and analytical characteristics of osmium and platinum complex are described. Interference of various foreign ions have studied and osmium is estimated selectively in the presence of constituents of platinum ores.

Coordination compounds with biomimetic N2S2 and N2S4 ligands: Synthesis and spectral studies on divalent transition metal complexes of benzildithiosemicarbazone and thiocarbohydrazone

Abstract Cobalt(II), nickel(II), copper(II) and palladium(II) complexes of benzildithiosemicarbazone (BDTSC), and tetraaza macrocyclic iron(II), cobalt(II), nickel(II) and copper(II) chelates derived from metal-ion catalyzed condensation (template synthesis) 1 of benzil and thiocarbohydrazide have been prepared and characterized by elemental analysis, conductance, magnetic moment and spectral data. The synthesis and spectral data of a tetraaza macrocyclic complex of Co(II) derived from the condensation of Co- BDTSC with benzil is included. The Co-BDTSC complex is found to react reversibly with molecular oxygen.

Rapid spectrophotometric determination of chromium(VI) using cyclohexane-1,3-dione bisthiosemicarbazone monohydrochloride

Cyclohexane-1,3-dione bisthiosemicarbazone monohydrochloride produces coloured solutions with the chromium(VI) ion in a sodium acetate - hydrochloric acid medium. The yellow species obtained (molar absorptivity 1.2 × 104 l mol–1 cm–1 at 370 nm) has been used for the spectrophotometric determination of micro-amounts of chromium(VI). Am important advantage of the method is that the tolerance limit for associated ions is very high. Hence this method can be used for the determination of chromium in alloy steels.

Rapid extraction spectrophotometric determination of platinum using anisaldehyde-4-phenyl-3-thiosemicarbazone as a chromogenic reagent

Abstract The synthesis, spectral characteristics and analytical applications of anisaldehyde-4-phenyl-3-thiosemicarbazone (APT) are described. A simple, rapid, selective and sensitive spectrophotometric method for the determination of platinum was developed based on the colour reaction between platinum (IV) and anisaldehyde-4-phenyl-3-thio-semicarbazone (APT) in the pH range 1.7 - 3.0. The yellow coloured species has an absorption maximum at 360 nm. The complexation is complete within 1 min. A five-fold excess of the reagent is required for complete complex formation. Beers law is obeyed over the concentration range 0.1 -20 ppm of Pt(IV). The mtilar absorptivity and Sandells sensitivity are 1.58 × 104 l. mol−1 cm−1 and 0.0123 ug of Pt(IV) cm−2, respectively. The effects of pH, time concentration of reagent, order of addition of reagents and the interference from various ions were investigated. The method has been employed for the determination of platinum in synthetic mixtures whose composition correspo...

Spectrophotometric determination of cobalt(II) in the presence of large amounts of iron with salicylaldehyde thiosemicarbazone

Abstract Cobalt(II) reacts instantaneously with the reagent at pH 5.0. The yellow complex has a molar absorptivity of 1.1 × 104 1 mol−1 cm−1. The method is applied to the determination of cobalt in steels after removal of iron with phosphate.

Sensitive and selective spectrophotometric method for the determination of trace amounts of osmium with 1,2,3-indanetrione monothiosemicarbazone

Sensitive and Selective Spectrophotometric Method for the Determination of Trace Amounts of Osmium with 1,2,3-Indanetrione Monothiosemicarbazone

Spectrophotometric determination of copper(II) and its application to a plant sample containing zinc, iron, and manganese

Abstract Salicylaldehyde thiosemicarbazone instantaneously forms a green complex with copper(II) in the optimum pH range 5–7. A fivefold molar excess of the reagent is sufficient for the full development of the color. Beers law is obeyed in the range 0.5–6.0 ppm of copper. The optimum concentration range as evaluated by Ringboms method is 1.4–5.8 ppm. At 375 nm the sensitivity of the reaction and the molar absorptivity are 0.006 μg cm−2 and 9.2 × 103 liters mol−1 cm−1, respectively. The effects of pH, reagent concentration, time, order of addition of the solutions, and the interference of various ions were investigated. Copper in plant samples, containing zinc, iron, and manganese, was determined.

Synthesis and characterization of complexes of (4-methoxybenzaldehyde)-4-phenyl-3-thiosemicarbazone

Abstract Some hitherto unknown complexes of 4-methoxy-benzaldehyde-4-phenyl-3-thiosemicarbazone (MBPT) with certain transition metal ions have been synthesized and characterized by spectral, magnetic,thermal, and conductance studies. All complexes except the mercury complex are hydrated, crystalline powders decomposed by mineral acids. IR spectral data suggests the coordination through the nitrogen and sulphur atoms. The electronic spectra indicate that Au(III), Os(VIII), Ru(III), Rh(III), Pd(II), Cu(II) and Ag(I) complexes are square planar. The high molar conductance value of the copper chelate suggests that the complex is a 1:1 electrolyte, where- as all other complexes are non electrolytes.