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Czakis-Sulikowska D., Czylkowska A., Markiewicz M., Frajtak M.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 11

1893-1901

EN

New mixed-ligand complexes of general formulae Ln(4-bpy)(CCl2HCOO)3źnH2O (4-bpy = 4,4'-bipyridine, Ln = lanthanide(III), n = 1 for Gd, n = 2 for Tb, Ho) and Tm(4-bpy)1.5(CCl2HCOO)3ź3H2O have been prepared and characterized by elemental and thermal analysis, IR spectroscopy and conductivity studies. The thermal properties of complexes were investigated in air atmosphere. During the heating the complexes decompose via intermediates to the oxides: Ln2O3 and Tb4O7. The principal volatile products of pyrolytic decomposition of Ho(III) and Tm(III) complexes, detected by a coupled TG-MS system are: C+, H2O+, CO2 + and species containing halogens and nitrogen. IR spectra suggest that 4-bpy and dichloroacetate groups are coordinated with Ln(III) ions.

2

Synthesis, Characterization and Thermal Decomposition of Yttrium and Light Lanthanides with 4,4'-Bipyridine and Dichloroacetates

Czakis-Sulikowska D., Czylkowska A., Markiewicz M.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 7

1267-1275

EN

A novel mixed-ligand complexes with empirical formulae: Ln(4-bpy)(CCl2HCOO)3.H2O (where:Ln =Y, Ce,Nd, Pr andEu, 4-bpy = 4,4'-bipyridine) were prepared and characterized by chemical and elemental analysis, IR spectroscopy and conductivity measurements (in methanol, dimethylformamide and dimethylsulfoxide). Analysis of the powder diffraction patterns showed that the obtained complexes are crystalline and isostructural compounds. The thermal properties of complexes in the solid state were studied under non-isothermal conditions in air atmosphere. During heating the complexes decompose via intermediate products to the oxides: Ln2O3 (Y, Nd, Eu), Pr6O11 and CeO2. A coupled TG-MS system was used to analyse principal volatile thermal decomposition (or fragmentation) products evolved during pyrolysis of Pr(III) and Nd(III) complexes. In air major profiles for ion currents are observed with m/z = 12, 18, 29, 30, 35, 36, 44, 47 amongst others.

3

Synthesis, Characterization and Biopotency of Some Metal(II) beta-Ketoiminates and Their Mixed-ligand Complexes

Osowole A. A., Fagade O. E.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 12

2039-2048

EN

VO(IV), Co(II) and Cu(II) complexes of beta-ketoimine [C6H5COH:CH(CH3)C:N(C6H4)Cl] and their mixed-ligand complexes with 2,2c- bipyridine (bipy) and 1,10-phenanthroline (phen) have been syn the sized and characterizedby elemental analysis, magnetic susceptibility, conductance, infrared and electronic spectral measurements. The ligand is bidentate, coordinating via the imine N and enolic O atoms. The magnetic moments and electronic spectra measurements corroborate a tetrahedral and square planar geometry for Ni(II) and Cu(II) complexes, the VO(IV) complex is five-coordinate square pyramidal while the Co(II) complex and the mixed- ligand complexes are six-coordinate, octahedral. The compounds are magnetically dilute and none is an electrolyte. The antimicrobial properties of these compounds against S. aureus, Bacilus subtilis, Bacillus cereus, Proteus sp, Klebsiella sp, Pseudomonas sp, and Salmonella spp are found to be generally good. The compounds, [VO(L)2], [VO(L)2(phen)] and [Co(L)2(bipy)] have comparable activity to Ciprofloxacin, a broad spectrum antibiotic. The minimum inhibitory concentrations (MICs) of the sen si tive compounds are between 3.0 and 9.0 mg/mL.

4

Synthesis and Spectral Studies of Mixed Ligand Complexes of Co(II) with 5-Nitrosalicylaldehyde and beta-Diketones, Hydroxyaryl Aldehydes or Ketones

Agrawal A., Sharma K. M., Prasad R. N.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 12

2081-2087

EN

Mixed ligand complexes of CoII of the type [CoLL'(H2O)2] (where HL = 5-nitro salicyl - aldehyde, HL' = salicylaldehyde, 2-hydroxyacetophenone, 2-hydroxypropiophenone, 2-hydroxybenzophenone, 2-hydroxy-1-naphthaldehyde, pentane-2,4-dione, 1-phenyl - butane-1,3-dione or 1,3-diphenylpropane-1,3-dione) have been syn the sized and characterized by elemental analyses, TLC, conductances, magnetic moments, IR, electronic and FAB mass spectra.

5

Dinuclear polypyridine complexes of 2,4,6-tris(2-pyridyl)-1,3,5-triazine: mixed ligand Ni(II), Co(II) and Cu(II) complexes containing dithiooxamide and thiosemicarbazide

Ibrahim S. A., Hammam A. M., El-Gahami M. A., Fouad D. M.

Bulletin of the Polish Academy of Sciences. Chemistry

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2003

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Vol. 51, No. 2

93-103

EN

A series of novel dinuclear mixed-ligand complexes having the general formula [M(2)(tpt)(L)(4]Cl(4)nH(2)O where M = Ni(II), Co(II) or Cu(II); tpt = 2,4,6-tris(2-pyridyl)-l,3,5-triazine; L = dithiooxamide (dto) or thiosemicarbazide (tsc); n = 2 — 4, have been synthesized and characterized. The tpt molecule is flexidentate, where it can behave as di- or tridentate and either mono- or dinucleating ligand. The coordination mode of the tpt to the M(II) apparently occurs through pyridyl and a triazine nitrogen atoms. The binary complexes have the formulas [Co(2)(tpt)Cl4H(2)O].2H(2)O, [Ni(tpt)Cl]Cl.5.5H(2)O and [Cu(tpt)Cl(2)].3H(2)O. All the mixed-ligand complexes are dinuclear with bridging tpt molecule and having an octahedral structure. Binary Co(II) and Cu(II) complexes are probably penta coordinated. The complexes under study were characterized by chemical analysis, spectral, molar conductance and thermal studies.

6

Chemiczne i biochemiczne aspekty kompleksów mieszanych

Kroczewska D., Kurzak B.

Wiadomości Chemiczne

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2001

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[Z] 55, 3-4

263-287

EN

During the last two decades thousands of important papers and some excelant review concerning complex equilibria have been published. In fact, most of these papers concern data on complex equilibrium, which does not involve species other than simple complexes with a completely homogenous coordination sphere Because mixed-ligand complexes are the most general and probable forms of existence of the elements in solution, we would like to present the mixed-ligand complexes in the aspect of their role in chemistry and in living systems. In the first part of this text we have lain particular emphasis upon literature data which show that it is worthwhile to assemble information on the formation, stability, structure and on the mutual influence of two ligands bound to the same metal ion, in the next part - on biochemical processes (transport, storage, inhibition of anzyme processes) which might be simulated by mixed-ligand complexes as "model systems" and at last - on own studies upon the mixed-ligand complexes of hydroxamic acid (a- or b-alaninehydroxamic acid) and one of polyamines with different metal ions. In order to find the answer for the following question: what kind of stoichiometry, geometry and binding mode there is in complexes which arrive in studied ternary systems? We used different methods: pH-metric method and spectroscopic ones (UV-VIS, EPR and NMR). The results obtained in our investigations and presented in this text show that the steric effect plays a very important role in the formation of the mixed-ligand complexes. In the case of bulky polyamine bonded in the zink(II) equimolar complex the coordination of a- or b-alaninehydroxamic acid is more favoured than the second polyamine ligand. There is no mixed-ligand complex formation in the case of ternary sestems with nickel(II). The reason for this is in the geometry of parent complexes - octahedral for nickel(II)-amine and square planar for nickel(II)-a-Alaha systems. The tridentate coordination of diethylenetriamine results in five-coordinated mixed-ligand copper(II) complexes in which the aminohydroxamate moiety adopts an equatorial-axial coordination mode.