NOPR Collection:

Schiff base derivatives of tungsten carbonyl

2016-07-20T06:32:02Z

Title: Schiff base derivatives of tungsten carbonyl Authors: Srivastava, Amar; Shrimal, A K Abstract: The Schiff bases (SB) viz., 1,2-bis(4-methylbenzylideneimine) propane (SB¹), l ,2-bis(4-methoxybenzylideneimine) propane (SB²), 1,2-bis(4-N,N-dimethylaminobenzylideneimine) propane (SB³), 1,2-bis( 4-methylacetophenoneimine)propane (SB⁴) and 1,2-bis(4-methoxyacetophenoneimine)propane (SB⁵) react with tungsten hexacarbonyl in xylene to give cis-disubstituted derivatives, cis-[(SB)W(CO)₄]. Schiff base bridged dinuclear [(Ph₃E)(CO)₄W(µ-SB)W(CO)₄(Ph₃E)] derivatives have been synthesized with [(Ph₃E)(CO)₅] (E = P or As). Cis[(SB)W(CO)₄] yielded [(S8)W(CO)₃X₂] when reacted with X₂(X = Br or I) but produced CO free product [(SB)WCI₄] after reaction with chlorine. The complexes have been characterized by elemental analysis, infrared and magnetic moment studies. Page(s): 785-790

Synthesis and characterization of niobium(V) complexes with terdentate ONO donor hydrazones

2016-07-20T06:32:02Z

Title: Synthesis and characterization of niobium(V) complexes with terdentate ONO donor hydrazones Authors: Naik, V M; Mallur, N B Abstract: The metal complexes of niobium(V) with 2-benzimidazolyl mercaptoaceto hydrazones have been synthesized in dry alcohol under nitrogen atmosphere and characterized by elemental analyses, molar conductance measurements, infrared, electronic and ¹H NMR spectral studies. The spectral studies show that the hydrazones reacts in enol form and act as dibasic terdentate ONO donor nature. The thermal stabilities have been studied and the kinetics of these complexes are calculated using Coats-Redfern and MKN methods. From the results, a coordination number seven for niobium ion in the complexes of the type Nb(L)₂CI is proposed. All the ligands and their niobium(V) complexes have been screened for their antimicrobial activity. Page(s): 780-784

Synthesis, characterization and redox behaviour of camphorquinone monooximate complexes of osmium(II), -(III) and -(IV)

2016-07-20T06:32:00Z

Title: Synthesis, characterization and redox behaviour of camphorquinone monooximate complexes of osmium(II), -(III) and -(IV) Authors: Bose, Doyel; Rahaman, Hafijur; Das, Pradyut Kumar; Sinha, Chittaranjan; Ghosh, Barindra Kumar Abstract: A group of dihalogenobis complexes of the type [OsX₂(HA)(A)] (1) and mixed-tris chelates of types [Os(A)(L)₂] - CIO₄.H₂O (2), Os(A)(Q)₂ (3) and [Os(A)(Q)₂]CIO₄.H₂O (4) [where X=CI or Br; HA=camphor-quinone monooxime; L = 2-(arylazo)pyridines and HQ=quinolin-8-ol and its derivative] have been prepared by distinctly different synthetic routes and characterized by microanalytical, IR, EPR, UV-Vis and electrochemical results. Reversible/nearly- reversible osmium(III)-osmium(II) and osmium(IV)-osmium(III) couples are invariably seen in all the complexes. Page(s): 774-779

Mixed-ligand complexes of cobalt(II) and nickel(II) with 2-sulphanylbenzothiazolate and (N,N) chelating ligands

2016-07-20T06:31:57Z

Title: Mixed-ligand complexes of cobalt(II) and nickel(II) with 2-sulphanylbenzothiazolate and (N,N) chelating ligands Authors: Singh, Nanhai; Gupta, Sushmita Abstract: A series of new, neutral [M(C₇H₄NS₂)₂(phen)] and salt-like [M(N-N₃]( C₇H₄NS₂)₂, mixed-ligand complexes {M=Co(II) or Ni(II); C₇H₄NS₂=2-sulphanylbenzothiazolate, N-N= 1,10-phenanthroline (phen) or ethylenediamine (en)} have been prepared and characterized by elemental analysis, IR, UV-visible and conductivity techniques. All the compounds exhibit σ_rt in the 10^-13-10^-6 S cm^-1 range. Temperature dependence (303-373 K) of the compressed pellet conductivity together with the band gaps in the 0.26-2.87 eV range show semiconducting behaviour of the compounds. Page(s): 771-773