NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)

Studies on the determination of palladium(II) by fluorescence quenching method with meso-tetra[ 4-(carboxymethy lenoxy)phenyl]porphyrin

Title: Studies on the determination of palladium(II) by fluorescence quenching method with meso-tetra[ 4-(carboxymethy lenoxy)phenyl]porphyrin

Authors: Fang, Yan-jun; Chen, Hui; Gao, Zhi-xian; Jin, Xiao-yong

Abstract: The spectrofluorimetric determination of Pd(II) using meso-tetra[4-(carboxymethylenoxy)phenyl]porphyrin (TCMOPPH₂) as an emission reagent has been investigated by measuring the decrease of its fluorescence intensity of the complexation of Pd(II)-TCMOPP. An emission peak of TCMOPPH₂, which is decreased linearly by adding of Pd(II), occurs at 394 nm in aqueous solution with excitation at 306 nm. The fluorescence intensity vary linearly with the concentration of palladium(II) in the range 3.754×10^-3~0.3625 μg/mL (SD = 0.034 for 10 times measurements) and the detection limit down to 2.715×10^-4 μg/mL. The interference of other noble metals and some of inorganic ions have been described, and the quenching mechanism has also been investigated according to the Stern-Volmer equation.

Page(s): 521-524

Structural studies on some trifluoro-β-diketonates of tin (IV) and lead(II)

Title: Structural studies on some trifluoro-β-diketonates of tin (IV) and lead(II)

Authors: Singh, Sudha; Gupta, Vishnu D

Abstract: Organotin(IV), tin(IV) and lead(II) trifluoro-β-diketonates have been prepared and characterized on the basis of IR, ¹H and ¹³C NMR data. All the organotin(IV) complexes are thermally stable liquids. SnCl₂(CF₃COCHCOPh)₂ (7) is characterized by X-ray crystallography which reveals a distorted cis-octahedral structure. X- ray diffraction analysis of Pb(CF₃COCHCOC₆H₄-p-Cl)₂ (8) shows a highly distorted trigonal bipyramidal structure.

Page(s): 513-520

Synthesis and characterization of azaphosphole complexes of ruthenium and rhodium

Title: Synthesis and characterization of azaphosphole complexes of ruthenium and rhodium

Authors: Jain, Vimal K; Hemrajani, Leena; Bansal, Raj K

Abstract: Reaction of azaphospholes (L) [2-phosphaindolizines (1) and 1,3-azaphospholo[5, 1-a]isoquinolines (2)] with [η⁵-Cp*RhCl₂]₂ (Cp* = pentamethylcyclopentadienyl) and [Ru(η⁶-cymene)Cl₂]₂ in 2:1 molar ratio in dichloromethane yields mononuclear complexes of the type [Cp*RhCl₂(L)] .H₂O and [Ru(cymene) Cl₂(L)] .H₂O. These complexes have been characterized by elemental analysis, FAB mass, IR and NMR (¹H and ³¹P) spectral data. Stereochemistry of these complexes has been discussed based on NMR data. NMR studies reveal a dynamic equilibrium between covalent and ionic forms of the complexes derived from 1 in solution.

Page(s): 506-512

Exchange kinetic studies on zirconium antimonophosphate

Title: Exchange kinetic studies on zirconium antimonophosphate

Authors: Mittal, S K; Singh, Pritpal

Abstract: Exchange kinetics of the alkaline earth metal ions with labile protons of the synthetic ion exchanger zirconium anti monophosphate has been studied, using the limited bath technique. Effect of concentration, particle size and temperature on the extent of exchange at the solution-solid in terrace are reported. The Boyd method for studing the kinetics of spherical particles is used to explain the results. Distinction between particle diffusion and film diffusion has been made by interruption test. The overall studies indicate that the effective diffusion coefficient consists of two components, an initial fast exchange and later a slow exchange, representing the inter-diffusion of counter ions through the pores of the exchanger matrix, with increase in temperature. The contribution of the faster component decreases, probably because the metal ions diffuse as dehydrated ions and the dehydration of the metal ions is easy at lower temperature. The effect of concentration and particle size on the exchange rate are also discussed.

Page(s): 500-505