K.M.M.S. Prakash

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...

Comeplexes of 1-(2′-hydroxybenzyl)-2-(2′-hydroxyphenyl)-benzimidazole with U(VI) and Ce(IV)

Abstract Some new U( VI ) and Ce( IV ) complexes of 1-(2′-hydroxybenzyl)-2-(2′-hydroxyphenyl)-benzimidazole have been prepared and characterized by spectrg magnetic and conductance studies. IR spectral data suggests that the ligand in all the complexes is monodenate through the tertiary nitrogen and that the phenolic oxygen is free from coordination. Conductivity measurements indicate that the nitrate and acetate complexes of U( VI ) are non-electrolytes, whereas the nitrate complex of Ce( IV ) is a 1:1 electrolyte.

Preparation and spectral properties of copper(II), iron(II) and iron(III) complexes of 1-(2′-hydroxybenzyl)-2-(2′-hydroxyphenyl)benzimidazole

Abstract A series of binuclear square planar complexes of copper(II) with hydroxy bridges and iron(II) and iron(III) binuclear octahedral complexes have been synthesized and studied by IR, electronic, vibrational spectral techniques and also by physicochemical techniques such as magnetic, thermal and conductance studies. The absorption bands appearing in the region greater than 16000 were attributed to n-→ σ*, π→π* and σ→σ* transitions within the ligand molecule, and metal to ligand charge transfer transitions. The ligand field bands were not assigned for the present complexes, because all the ligand fields bands were obscured by π→π* transitions and charge transfer bands of high intensity. The copper- (II) complexes were assumed to be square-planar complexes since a significant absorption band was detected in the range below 17000 cm −1 . A strong IR band appearing around 1480 cm −1 was assigned to the C=N stretching mode, and it is observed that this band was shifted to lower frequencies upon coordination. A magnetic moment lower than 1.9 BM for all copper(II) complexes is consistent with a square-planar geometry. The values for iron(II) and iron(III) are somewhat less than the reported values, which may be due to metal-metal inter- action. Conductance studies show the existence of both ionic and non-ionic complexes.

Synthesis and Characterization of Complexes of Co(II) and Mn(II) with 1-(2′ -Hydroxysenzyl)-2-(2′-Hmroxyphfnyl)-Bexzimidazole

Abstract A series of low spin octahedral complexes of Co(II) and high spin octahedral complexes of Mn(II) have been synthesized and studied by IR, electronic, vibrational spectral methods and also by physico-chemical methods such as magnetic thermal and conductance studies. The absorption bands appearing in the region greater than 16000 cm−1 were attributed to n →σ∗, σ, and σπ∗ transitions within the ligand molecules and metal → ligand charge transfer transitions. The ligand field bands were not assigned for the present complexes, because all the ligand field bands were obscured by σπ∗ transitions and charge transfer bands of high intensity. The Co(II) complexes were assumed to be low spin octahedral, since a significant absorption band was detected in the range round 18000 cm−1. A Strong IR band appearing around 1480 cm−1 was assigned to the C = N stretching mode and it is observed that this band was shifted to lower frequencies upon coordination. A magnetic moment lower than 1.9 BM for all cobalt (II) c...

Thermal behaviour of copper(II), iron(II) and iron(III) complexes of 1-(2'-hydroxybenzyl)-(2'-hydroxyphenyl)-benzimidazole

Abstract A series of square planar complexes of copper(II) with hydroxy bridges and octahedral complexes of iron(II) and iron(III) have been synthesized and their thermal and differential thermal behaviour studied. From the thermal and differential thermal analyses, the order of their thermal stability is proposed.

Thermal behaviour of transition metal complexes of 4- methoxybenzaldehyde-4-phenyl-3-thiosemicarbazone

Abstract Some new transition metal complexes of 4-methoxybenzaldehyde-4-phenyl-3-thiosemi-carbazone (MBPT) have been synthesized and their thermal behaviours have been studied. All complexes except the mercury complex are hydrated crystalline powders decomposed by mineral acids. Copper(II), cobalt(II), nickel(II), palladium(II), gold(III), silver(I) and mercury(II) were estimated by reported methods.