Wyniki wyszukiwania - BazTech

1

Synthesis and Magnetism of Copper(II)-Ln(III)-Copper(II) (Ln = La, Nd, Eu, Gd, Tb, Dy, Ho, Er) Heterotrinuclear Complexes with N,N_-Bis(2-methyl-2-aminopropyl)oxamidocopper(II)

Li Y., Yan C., Wang S., Zhang G.

Polish Journal of Chemistry

|

2006

|

Vol. 80, nr 9

1425-1433

EN

Eight new mi-oxamido-bridged copper(II)-lanthanide(III)-copper(II) heterotrinuclear complexes formulated as Cu2(oxmap)2Ln(NO3)3 (Ln = La, Nd, Eu, Gd, Tb, Dy,Ho, Er), where oxmap stands for N,N'-bis(2-methyl-2-aminopropyl)oxamido dianions, have been synthesized by the strategy of "complex as ligand", and characterized by elemental analyses, molar conductivity measurements, IR and electronic spectral studies. The variable temperature magnetic susceptibility (2~300 K), ESR measurements and studies of the Cu2(oxmap)2Gd(NO3)3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J(Cu-Gd) = +2.19 cm-1, while an antiferromagnetic coupling is detected between the terminal copper( II) ions with the exchange integral J'(Cu-Cu) = _0.15 cm-1, on the basis of the spin Hamiltonian operator [H = -2J(S Cu1. S Gd + S Cu2. S Gd)-2J'(ScCU1.SCu2)].A plausible mechanism for the ferromagnetic coupling between copper(II) and gadolinium(III) is discussed in terms of spin polarization.

2

Characterization of CuxS Layers Obtained by Adsorption-Diffusion Method on by Adsorption-Diffusion Method on Polycaproamide from K2S5O6 Solutions

Krylova V., Dukstiene N.

Polish Journal of Chemistry

|

2006

|

Vol. 80, nr 9

1435-1447

EN

CuxS layers on polycaproamide, obtained by the adsorption-diffusionmethod, have been studied. These layers are formed when the ions of pentathionate (K2S5O6) sorbed into polycaproamide react with a solution of copper(I) salt. By X-ray diffraction studies it was determined that the CuxS layers obtained are of three phases, comprising covellite (CuS), geerite (Cu1.6S), anilite (Cu1.75S) and chalcocite (Cu2S). The concentration ratio of the phases depends on the period of polycaproamide sulfuration in a potassium pentathionate solution. Chalcocite prevails in the composition of CuxS film on PKA. The films were characterized by means of IR spectroscopy. IR absorption spectra were investigated in the region of the wavenumbers 200-1400 cm-1. The characteristic absorption maxima were found in the regions 242-243, 268-290, 339-384, 422-463, 538, 611-612, 879-929, 1018-1095, 1186-1224 cm-1 and assigned, respectively, to delta(S-S-S) and ni (Cu-S), gamma r(SO3), ni(S-S) and ni(Cu-S), delta as(O-S-O), delta s(O-S-O), ni (Cu-S), ni s(S-O) and ni as(S-O). Measurements of electrode potentials in CuSO4 solutions of different concentration have shown that the response time and stability of electrodes in Cu2+ ion solutions depend on the phase composition. Electrodes composed from Cu1.75S and Cu1.6S are not stable in CuSO4 solutions. The response time of a Cu2S electrode depends on concentration change. The change of the potential with an active Cu2+ ion concentration is linear in the range of 1.10-3-4.10-2mol_dm-3, the slope of the linear portion being 31.5mVper decade. The obtained experimental values have been compared with the theoretical values calculated on the basis of thermodynamic data.

3

Synthesis and Magnetism of Cu(II)-Ln(III)-Cu(II) (Ln+La, Nd, Gd, Tb, Ho, Er) Trinuclear Complexes Bridged by N, N'-Bis[3-dimethylamino)propyl]oxamido

Yan C., Li L., Li Y., Zhang G., Sun W.

Polish Journal of Chemistry

|

2005

|

Vol. 79 / nr 9

1425-1433

EN

Six new mi-oxamido-bridged copper(II)-lanthanide(III)-copper(II) heterotrinuclear complexes described by the overall formula Cu2(dmoxpn)2Ln(NO3)3 {Ln = La, Nd, Gd, Tb, Ho, Er; dmoxpn = N,N'bis[3-(dimethylamino)propyl]oxamido dianions} have been synthesized and characterized by elemental analyses, molar conductivity measurements, IR and electronic spectral studies. The variable-temperature susceptibility (4.2~300 K), ESR measurements, and studies of the Cu2(dmoxpn)2Gd(NO3)3 complex have revealed that the central gadolinium(III) and terminal copper(II) ions are ferromagnetically coupled with the exchange integral J(Cu-Gd) = +6.85 cm-1, while an antiferromagnetic coupling is detected between the terminal copper(II) ions with J'(Cu-Cu) = -0.27 cm-1, on the basis of the spin Hamiltonian operator [H=-2J(S Cu1.S Gd+S Cu2.Gd)-2J(S Cu1.S Cu2)]. A plausible mechanism for the ferromagnetic coupling between copper(II) and gadolinium( III) is discussed in terms of spin polarization.

4

Synthesis and Magnetic Properties of mi-Oxalato-Bridged Cu(II)-Fe(III)-Cu(II) Heterotrinuclear Complexes

Wang H. D., Li Y. -T., Yan C. -W., Zeng X.-C.

Polish Journal of Chemistry

|

2002

|

Vol. 76 / nr 5

637-644

EN

Three new _-oxalato-bridged copper(II)-iron(III)-copper(II) heterotrinuclear complexes described by the overall formula [Cu2Fe(ox)3L2]ClO4, where ox represents the oxalato dianions and L stands for 5-phenyl-1,10-phenanthroline (Ph-phen), 4,7-diphenyl- 1,10-phenanthroline (Ph2-phen) or 5-chloro-1,10-phenanthroline (Cl-phen), have been synthesized and characterized by elemental analyses, molar conductivity and magnetic moment (at room-temperature) measurements, IR and electronic spectral studies. It is proposed that these complexes have extended ox-bridged structures, consisting of two copper(II) and an iron(III) ions, in which the central iron(III) ion has an octahedral environment and the end capped two copper(II) ions have a square-planar environment. The variable-temperature susceptibilities of [Cu2Fe(ox)3(Ph-phen)2]ClO4 complex were measured and studied in the 4.2~300 K range. The least-squares fit of the experimental susceptibility based on the spin Hamiltonian operator, _ _ _ H = JS S 1 2 _ _ 2 , yielded J = -9.89 cm-1. The magnetic coupling parameter is consistent with an antiferromagnetic exchange interaction between the copper(II) and iron(III) ions through the oxalato-bridge in the complex.

5

Syntesis and Ferromagnetic Interaction in Oxalato-Bridged Copper(II)-Chromium(III)-Copper(II) Heterotrinuclear Complexes

Li Y., Yan C. -W., Guan S. -H.

Polish Journal of Chemistry

|

2002

|

Vol. 76 / nr 12

1655-1663