Salah B. El-Maraghy

Heteronuclear complexes of oxorhenium(V) with Fe(III), Co(II), Ni(II), Cu(II), Cd(II) and UO2(VI) and their biological activities

Heteronuclear complexes containing oxorhenium(V), with Fe(III), Co(II), Ni(II), Cu(II), Cd(II) and UO2(VI) ions were prepared by the reaction of the complex ligands [ReO(HL1)(PPh3)(OH2)Cl]Cl (a) and/or [ReO(H2L2)(PPh3)(OH2)Cl]Cl (b), where H2L1 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(5,6-diphenyl-1,2,4-triazine-3-ylhydrazone) and H3L2 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(1H-benzimidazol-2-ylhydrazone), with transition and actinide salts. Heterodinuclear complexes of ReO(V) with Fe(III), Co(II), Ni(II), Cu(II) and Cd(II) were obtained using a 1 : 1 mole ratio of the complex ligand and the metal salt. Heterotrinuclear complexes were obtained containing ReO(V) with UO2(VI) and Cu(II) using 2 : 1 mole ratios of the complex ligand and the metal salts. The complex ligands a and b coordinate with the heterometal ion via a nitrogen of the heterocyclic ring and the nitrogen atom of the C=N7 group. All transition metal cations in the heteronuclear complexes have octahedral configurations, while UO2(VI) complexes have distorted dodecahedral geometry. The structures of the complexes were elucidated by IR, ESR, electronic and 1H NMR spectra, magnetic moments, conductance and TG-DSC measurements. The antifungal activities of the complex ligands and their heteronuclear complexes towards Alternaria alternata and Aspergillus niger showed comparable behavior with some well-known antibiotics.

Syntheses and structural transformations of oxorhenium(V) complexes with triazine and imidazole derivatives: mixed ligand complexes with thiocyanate, 8-hydroxyquinoline and 1,10-phenanthroline

Mononuclear oxorhenium(V) complexes [ReO(HL1 or H2L2)(PPh3)(OH2)Cl]Cl, {H2L1 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(5,6-diphenyl-1,2,4-triazine-3-ylhydrazone) and H3L2 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(1H-benzimidazol-2-ylhydrazone)}, have been synthesized by ligand exchange with trans-trichloromonooxo-bis(triphenylphosphine) rhenium(V). The reaction of a 1 : 1 mixture of either NH4SCN, 1,10-phenanthroline (1,10-phen) or 8-hydroxyquinoline (8-OHquin) and H2L1 or H3L2, with trans-ReOCl3(PPh3)2 yielded the mononuclear oxorhenium(V) complexes, [ReO(HL1 or H2L2)(PPh3) (SCN)Cl], [ReO(HL1)(1,10-phen)Cl]Cl, [ReO(H2L2)(1,10-phen)(OH2)]Cl2·H2O and [ReO(HL1 or H2L2) (8-Oquin)Cl]. Thermal studies on these complexes showed structural transformations from mononuclear into binuclear complexes. [Re2O3(HL1 or H2L2)2(PPh3)2Cl2], [Re2O2(μ-L1 or L2)2(SCN)2] and [Re2O3 (H2L2)2(1,10-phen)2]Cl2, were synthesized pyrolytically in the solid state from the respective precursor rhenium complexes. The structures of all complexes and the corresponding thermal products were elucidated using elemental analyses, conductance, IR and electronic absorption spectra, magnetic moments and 1H NMR and TG-DSC measurements. The prepared complexes and their thermal products have octahedral configurations. The ligands H2L1 or H3L2 behave as monoanionic bidentate or monoanionic tetradentate ligands towards the oxorhenium ions. The antifungal activities of the metal complexes towards Alternaria alternata and Aspergillus niger were tested and showed comparable behavior with well known antibiotics.

Sulfitoamine Complexes of Cobalt(III)

Abstract Monosulfito and bis(hydrogensulfito) cobalt(III) complexes were prepared using sodium sulfite and sodium metabisulfite salts respectively. The two types of products showed different and characterizing patterns of IR and UV-visible spectra. They both contain Co-SO3 linkages and the sulfite groups have similar or different site symmetries in the same compound.

Normal sulphites of metals

SummaryNormal sulphites of metals were prepared by the reaction of metal salts with sodium metabisulphite, in aqueous acid solutions, to prevent the formation of basic sulphites. Visible spectra and magnetic moments show that the transition metal sulphites have distorted octahedral structures. The i.r. spectra showed that the sulphite groups act as O-bonded bridging ligands linking the metal atoms in polymeric chains.

Palladium (II) Hydrazopyrazolone Complexes

Palladium (II) complexes with 1-pheny1-3-methy1-4-(arylhydrazo)-5- pyrazolone dyes were studied spectrophotometrically. Pd (II) forms 1:1 and 1:2 complexes with the ligands by the replacement of their phenolic and hydrazo protons. The ligands behave as tridentate in the 1:1 complex and as bidentate in the 1:2 complex. The sability constants of these complexes are dependent on the type of substituents in the benzene ring of the arylazo moiety.

Infrared And Visible Spectra And Magnetic Properties Of Sodium And Potassium Bis(2,4-Pentanedionato) Selenito Cobaltate (II) And Nickelate (II), Complexes

Inorganic anions are commonly used as ligands in coordination chemistry (1, 2). The properties of the selenite anions in aqueous solution are important in determining selenito complex formation. In dilute aqueous solutions, selenous acid is dibasic (K1 = 4 x 10-3; K2 = 10-8 )forming HSe03 and Se03 anions. At higher concentrations, extensive dimerization occurs with these species to yield-H(Se 02) 3 2 H2 (Se03)2 2 , H3(Se 03)2 and H4(Se 03)2. Limited information is available about the selenite group as a ligand in coordination chemistry. A general survey on the preparation and structure of selenites and mixed selenito complexes of transition metals will be represented later on. The study of the I.R. modes of the selenite group in these complexes is still lacking although the X-ray structure of some normal selenites is already established. Also, the magnetic behaviour of these complexes needs furtehr investigation and study. The structure of these complexes will be deduced from their visible spectra, magnetic moments and I.R. spectra.