NOPR Collection:

Synthesis and characterization of some lanthanide complexes of 2,6-diacetylpyridine 2-thenoylnicotinoyldihydrazone

1999-12-01T00:00:00Z

Title: Synthesis and characterization of some lanthanide complexes of 2,6-diacetylpyridine 2-thenoylnicotinoyldihydrazone Authors: Singh, B; Singh, T B Abstract: The complexes of the type [Ln(H₂dapthnh)Cl(H₂O)₂]-CI₂[Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy; H₂dapthnh = 2,6- diacetylpyridine-2- thenoylnicotinoyldihydrazone] have been synthesized by reacting [Ln (Hdapth)C1₂(H₂O)₃]CI [Hdapth=2,6- diacetylpyridinemono(2-thenoylhydrazone) with nicotinoylhydrazine in ethanol and characterized by analytical, molar conductance, IR , ¹H NMR, electronic and FAB mass data. The position and shape of the hypersensitive transitions ⁴I_9/2 → ⁴G_5/2_, ²G_7/2the neodymium complex indicate eight coordinate geometry round the Ln(III) ions. The symmetry of the eight coordinate Eu(III) and Tb(III) complexes has been determined from the emission spectra. Page(s): 1286-1290

Thermodynamics of aqueous solutions of p-toluenesu1phonic acid and its some alkali metal salts in the temperature range of 298.15 K to 353.15 K

1999-12-01T00:00:00Z

Title: Thermodynamics of aqueous solutions of p-toluenesu1phonic acid and its some alkali metal salts in the temperature range of 298.15 K to 353.15 K Authors: Das, Bijan; Pitzer, Kenneth S. Abstract: The available experimental osmotic coefficients for aqueous solutions of p-toluenesulphonic acid and its lithium, sodium and potassium salts have been analyzed in the framework of the Pitzer ion-interaction model in the temperature range of 298.15 K to 353.15 K. The standard deviation of fit (in the osmotic coefficient) ranges from 0.0013 to 0.0044. Parameters derived from the fit have been used to calculate the activity coefficients. These activity coefficients are compared with those reported earlier from osmotic coefficients by an integration procedure and a good agreement is found. Page(s): 1261-1263

Catalytic hydrogenation of tetrahydrophthalic anhydride

1999-12-01T00:00:00Z

Title: Catalytic hydrogenation of tetrahydrophthalic anhydride Authors: Ruina, Yang; Caiyun, Li; Yimin, Hou; Xiaoyuat, Hu; Douman, Jin Abstract: Catalytic hydrogenation reaction of tetrahydrophthalic anhydride(THPA) to hexahydrophthalic anhydride(HHPA) has been studied. The effects of temperature, pressure, time and solvent on catalytic reaction have also been investigated. Raney Ni(T-1 ) has high activity towards hydrogenation of THPA to HHPA. The amount of HHPA formed constantly increases with increasing temperature in the experimental temperature range (70-1 00°C). The experimental results show that conversion of THPA and selectivity to HHPA reach 88% and 100%, respectively under the appropriate reaction conditions (T-1 Raney Ni: 7%, H₂pressure: 4.5 MPa, 45% DMF solution, reaction time 3.0h, temperature: 95°C). Page(s): 1259-1260

Synthesis,characterisation, thermal, kinetic and mechanistic study of complexes of photosubstituted octacyano-molybdate(IV) and -tungstate(IV) of pyrazine with cobalt(II) chloride

1999-12-01T00:00:00Z

Title: Synthesis,characterisation, thermal, kinetic and mechanistic study of complexes of photosubstituted octacyano-molybdate(IV) and -tungstate(IV) of pyrazine with cobalt(II) chloride Authors: Ali, S I; Majid, Kowsar Abstract: The photosubstituted pyrazine complexes of octacyano-molybdate(IV) and-tungstate(IV) form complexes with cobalt(II) chloride, with the same stoichiometric and thermal behaviour. The general formula proposed for the complex is Co[M(Pz)(CN)₂(OH)₂]Cl₂ xH₂O where Pz = pyrazine, M = Mo (IV) and x = 1 for complex I and M = W(IV) and x = 1.5 for complex II. The complexes have been characterized by IR spectroscopy, which shows pyrazine to behave as a bidentate ligand. The thermogravimetric and differential scanning calorimetric studies on the complexes give a sequential decomposition process. The thermodynamic parameters like activation energy, pre-exponential factor and entropy of activati on have been calculated using different methods, like Doyle's, Coats and Redfern and Arrhenius methods. The enthalpy of the reaction has been obtained from DSC curves. The order of stabilities of different coordinating moieties is CN>CI>OH, which is same for both the complexes. Page(s): 1232-1238