NOPR Collection:

A new chalcogenide membrane bismuth ionselective electrode

Sat, 01 Apr 2000 00:00:00 GMT

Title: A new chalcogenide membrane bismuth ionselective electrode Authors: Sharma, P K; Sudersanan, M; Mathur, P K Abstract: A bismuth ion selective electrode based on chalcogenide glass membrane has been fabricated and evaluated. The electrode responds to the bismuth ion concentration in a Nernstian fashion at a pH of 1.5. Several common ions do not show any interference. The electrode can be used as an indicator electrode for titration of bismuth with EDTA. Page(s): 472-474

Mixed ligand complexes of nickel(II) with imidazoles and some dipeptides

Sat, 01 Apr 2000 00:00:00 GMT

Title: Mixed ligand complexes of nickel(II) with imidazoles and some dipeptides Authors: Nair, M Sivasankaran; Subbalakshmi, G Abstract: The computer based analysis of the pH titration data in the Ni(II)-imidazole (him)/histamine (hist)/L-histidine(his) (A)glycyl-L-phenylalanine(glyphe), glycyl-L-tyrosine(glytyr) and L-tyrosylglycine (tyrgly) (B) systems shows the presence of NiAB, NiABH_-1, NiA₂B or NiAB₂ mixed ligand species. The results demonstrate that him, hist and his(A) are respectively mono-, bi- and tri-dentate and the dipeptide(B) ligands are bidentate in NiAB, NiA₂B and NiAB₂ complexes. The amide deprotonated dipeptide (BH_-1) appears to bind in a tridentate mode in the NiABH_-1 species in the him(A) systems, while the trends in results clearly demonstrate the bidentate binding of (BH_-1) in the hist/his(A) mixed ligand systems. Page(s): 468-471

Spectrophotometric determination of trace amounts of vanadium(V) with isothipendyl hydrochloride

Sat, 01 Apr 2000 00:00:00 GMT

Title: Spectrophotometric determination of trace amounts of vanadium(V) with isothipendyl hydrochloride Authors: Melwanki, M B; Seetharamappa, J Abstract: Isothipendyl hydrochloride is proposed as a selective and sensitive reagent for the rapid spectrophotometric determination of vanadium(V). The reagent instantaneously forms a red coloured species with vanadium(V) in phosphoric acid medium which exhibits maximum absorbance at 500 nm with Sandell's sensitivity of 6.55 ng cm^-2. Beer's law is valid over the concentration range of 0.2-4.8 ppm with an optimum concentration range of 0.4-4.5 ppm. The method has been successfully applied to the analysis of vanadium steels and minerals. Page(s): 465-467

Synthesis, characteristics and redox properties of uranyl complexes with diamine ligands having ONNO and ONNNO donor groups.

Sat, 01 Apr 2000 00:00:00 GMT

Title: Synthesis, characteristics and redox properties of uranyl complexes with diamine ligands having ONNO and ONNNO donor groups. Authors: Gandhi, Jesal B; Kulkarni, Neelima D Abstract: Complexes of dioxouranium(VI) with ONNO and ONNNO coordinating diamine ligands have been synthesised. The complexes undergo irreversible reductions at more negative potentials and have longer O=U=O bond lengths compared to the corresponding diimine complexes suggesting less delocalisation of the electron density into the ligand orbitals. Page(s): 461-464