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3 Polish Journal of Chemistry

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Stability and ESR Spectra of Ni(III) Tetraazamacrocyclic Complexes in Nitrate and Chloride Solutions

100%

Taraszewska J. , Sadło J. , Michalik J. , Korybut-Daszkiewicz B.

tom Vol. 74, nr 6

813-822

Complexes [NiIII(cyclam)Cl2]Cl (10, NiIII(cyclam)(NO3)2]lO4 (2) and [NiIII(2-methyl-cyclam)(NO3)2]ClO4 (3) were isolated and the stability of Ni(III) was studied by UV-VIS spectrophotometry as a function of NaCl and NaNO3 concentration. In complexes 2 and 3 the decay of Ni(III) followed the first order kinetics in aqueous and nitrate solutions up to 1 ol/dm3. In complex 1 the first order kinetics was observed only in aqueous and saturated NaCl solutions. With increase in NaNO3 concentration the stability of Ni(III) in complexes 2 and 3 increased however, in complex 3 it was lower than in complex 2. Stability of Ni(III) in complex 1 increased also with increasing NaCl concentration but it diminished starting from 2 mol/dm3 NaCl. The forms of complexes depending on the salt concentration were characterized by the ESR technique.

Synthesis and Physico-Chemical Studies of 14-Membered Tetraazamacrocyclic Complexes of Co(II), Ni(II), Cu(II) and Zn(II) DErived from 3,4-Diaminobenzophenone

88%

Khan T. , Ghani S.

2005

tom Vol. 79 / nr 5

817-823

A new series of 14-membered tetraazamacrocyclic complexes [MLX2] (M = Co(II), Ni(II), Cu(II), and Zn(II), X = Cl or NO3) have been synthesized by the condensation reaction of 3,4-diaminobenzophenone with 1,3-dibromopropane in the presence of metal ions as templates in methanol as solvent. The macrocyclic complexes have been characterized on the basis of elemental analysis, IR, 1H NMR, EPR, UV-visible, magnetic susceptibility and conductivity measurements at room temperature. An octahedral geometry has been proposed for all of the complexes where two coordination sites are occupied by Cl or NO3 and the other four sites by secondary amine. The low conductivity data suggests their non-ionic nature.

Kinetic, Spectroscopic and Magnetic Properties of 1,4,8,11-Tetraazacyclotetradecanenickel Bi- and Trivalent Complexes

75%

Banaś B. , Nahorska M. , Korybut-Daszkiewicz B. , Mroziński J.

tom Vol. 77 / nr 1

21-29

Nickel(II) and nickel(III) complexes of formula [NiIILCl2] and [NiIIILCl2]+ containing tetraaza macrocyclic ligands with nitrogen donor atoms, where L = [14]aneN4 (L1), 2-Me[14]aneN4 (L2), 5,12-Me2[14]aneN4(L3), 5,7,7,12,14,14-Me6[14]aneN4 (L4), form stable crystals with a pseudo-octahedral geometry of central atom. This work concerns the methyl analogues of Ni(II) and Ni(III) complexes. Magnetic and spectroscopic measurements gave values of spectroscopic parameter g and paramagnetic temperature dependence characteristic for this type of compounds. Their properties were investigated using EPR, reflectance spectroscopy and IR techniques. The Faraday method was used for the investigation of magnetic susceptibility between 4.2-300 K.