Mahmoud S. El-Meligy

Mixed Ligand Complexes of 5-arylazo-8-hydroxyquinoline and α-amino Acids with Co(II), Ni(II) and Cu(II)

Ten mixed ligand complexes of the type [M(X-QA)(aa)] and [Ni(X-QA)2(Haa)(H2O)],where X-HQA=5-arylazo-8-hydroxyquinoline derivatives, M=Co(II) orCu(II) and Haa=glycine (gly), alanine (ala) or methionine (met), have been prepared. The complexes have been characterized by elemental analysis, IR and electron spectra and thermal analysis. A tetrahedral structure has been proposed for the cobalt(II) and copper(II) complexes with bidentate coordination of amino acids. The nickel(II) complexes have been assigned an octahedral structure with the amino acids acting as monodentate ligands. The thermal behaviour of the complexes has been studied before and after γ-irradiation.

Complexes of tris(o-phenanthroline)nickel(II) and copper(II) bromide with dithiocarbamates derived from α-amino acids

Complexes of 1,10-o-phenanthroline (o-phen)-NiII and CuII with dithiocarbamates derived from α-amino acids (glycine, phenylalanine, alanine, methionine and tryptophan) were synthesized and characterized by chemical analysis, spectral and thermal studies and by biological screening; the complexes are non-electrolytes. The empirical formula are [Ni(o-phen)2(aadtc)] and [Cu2(o-phen)2(phaladtc)(H2O)2Br2] where, aadtc = glycinyl-, phenylalaninyl-, alaninyl-, methioninyl- and tryptophanyldithiocarbamate and phaladtc = phenylalaninyldithiocarbamate. The structure of these complexes is probably octahedral. Molecular association through hydrogen bonding between the —NH and the carboxylate groups is proposed for the NiII complexes. The CuII complex is dimeric with the phenylalaninyldithiocarbamate acting as a bridge.

Characterization of Some New Nickel(II) Dithiolato Mixed Ligand Complexes With Nitrogen Donor Ligands: Magnetic, Spectral, and Thermal Studies

Abstract The following mixed ligand complexes were prepared and characterized: (Etdtp)2Ni (Boz)2, (Etdtp)2Ni (Btz)2, (Cydtp)2Ni (Btz)2 (Etxan)2Ni (Boz)2, (Etxan)2Ni (Btz)2, (Mexan)2Ni (morph)2, (Prxan)2Ni (morph)2, (Buxan)2Ni (morph)2, (Acac)2Co(Boz)2, (Acac)2Co(Btz)2, (Acac)2Ni(Boz)2, and (Acac)2Ni (Btz)2. Etdtp [dbnd] diethyldithiophosphate, Cydtp [dbnd] dicyclohexyldithiophosphate, Mexan [dbnd] methylxanthate, Etxan [dbnd] ethylxanthate, Prxan [dbnd] propylxanthate, Buxan [dbnd] butylxanthate, Acac [dbnd] acetylacetonate, Boz [dbnd] benzoxazole, Btz [dbnd] benzothiazole, and morph [dbnd] morpholine. The compounds were identified on the basis of their elemental analysis, IR and UV-VIS spectra, magnetic measurements, and thermal analysis.

Anionic complexes of some transition metals containing mixedβ-diketonato and alkylxanthato ligands

SummaryEleven complexes of the type K[M(acac)(Rxan)2] and K[M(TTA)2(Rxan)], where M=CoII or NiII, acac=acetylacetonate, TTA=thenoyltrifluoroacetonate, and Rxan=alkylxanthate, R=methyl-, ethyl-, propyl-, butyl-, or cyclohexyl-, have been prepared. The magnetic and spectral data indicate that the complexes are octa-hedral and that the xanthate group is attached in a bidentate fashion to the metal ions. The conductivity data are commensurate with the ionic character in the complexes. T.g.a. were made for some of the complexes.

Synthesis, Spectral and Thermal Studies on Cobalt(II), Copper(II), Nickel(II) and Zinc(II) Chelates with p-tolylsalicylaldimine and Some Amino Acids

Abstract New cobalt(II), copper(II), nickel(II) and zinc(II) complexes of the p-tolyIsalicylaIdimine Schiff base (sal-TH) and some amino acids have been prepared. The complexes have the general formula [M(sal-T)(aa)].nH2O where M = Co(II), Cu(II), Ni(II) and Zn(II); sal-T = monoanion of the Schiff base p-tolylsalicylaldimine; aa = monoanion of the amino acids phenylalanine (Phala), tyrosine (tyr) or methionine (met); n = 0 for M = Co(II), Cu(II) or Ni(II) and n = 2 for M = Zn(II). The complexes have been characterized and studied by elemental analyses, conductivity, IR and UV-V1S spectroscopy as well as thermogravimetry. The Cu(II) complexes have been proposed to possess a square-planar structure while the Co(II), Ni(II) and Zn(II) complexes have an octahedral structure attained by mutual intermolecular interactions among the adjacent mixed amino acid-Schiff base molecules. The thermal decomposition reaction order and activation energy have been computed by means of the Coats-Redfern and Horowitz-Metzger methods. The biological activity of selected complexes against some bacteria and fungi have been tested.

Complexes of bis(Diphehyldithiophosphinato)nickel(II) with Nitrogen and Sulphur Containing Ligands

Abstract Mixed ligand complexes of bis(diphenyldithiophosphinato)nickel(II) with some azoles and morpholine (morph) having the general formula Ni (Ph2PS2)2(azole)2 or Ni (Ph2PS2)2 (morph)2 have been prepared. Displacement reactions between bis(diphenyldithiophosphinato)-nickel(II) and dithizone (H2Dz), sodium diethyIdithiocarbamate (NaEt2dtc) Or potassium cyclohexyldithiocarbanate (Cydten) produced the mixed ligand complexes Ni(Ph2PS2) (HDz), Ni (Ph2PS2) (Et2dtc) and Ni(Ph2PS2) (Cydtcn). The newly prepared compounds were characterised on the basis of their analysis, magnetic susciptibility, infrared, electronic spectra as well as thermal analysis.

COORDINATION PROPERTIES OF SOME MIXED AMINO ACID METAL COMPLEXES

A series of mixed-ligand complexes of the formulae [Co (tyr)(gly)(H2O)2], [Co(tyr)(ala)(H2O)2], [Co(tyr)(thr)(H2O)2], [Co(tyr)(met)(H2O)2],[Ni(tyr)(gly)(H2O)2], [Ni(tyr)(ala) (H2O)2] and [Ni(tyr)(thr)(H2O)2], where tyr = L-tyrosine, gly = glycine, ala = alanine, thr = threonine, met = L-methionine has been prepared and characterised on the basis of elemental analyses, spectroscopic, thermal analysis and X-ray powder diffraction data. An octahedral structure has been proposed for all of the prepared complexes. The thermal behaviour of the complexes has been studied before and after γ-irradiation.

Mixed dithizonato-alkylxanthato complexes of Ni(II): spectral, magnetic, and thermogravimetric studies

Mixed ligand complexes of the type Ni(ROCS2)HDz) have been prepared, where R = methyl, ethyl, propyl, butyl and cyclohexyl, and HDz = dithizonate anion. These complexes were identified on the basis of spectroscopic measurements (IR, UV-VIS and NMR), magnetic moment values, thermogravimetric analysis, and analytical data. The results permit assignment of a tetrahedral structure for these complexes.

Complexes of Iron(III) Containing Heterocyclic Ligands

Abstract The following mixed ligand complexes of iron(III) have been synthesised and characterised: Fe(Pipdtc)2.,(HDz); Fe(Pipdtc)(OX)2, Fe(Pipzdtc)(OX)2, Fe(morphdtc)(OX)2, Fe(Etxan)(OX)2, Fe(i-Prxan)(OX)2, Fe(Buxan)(OX)2, and Fe(i-Amxan)(OX)2. The spectral data permited us to assign an octahedral structure around iron(III). The thermal decomposition of the complexes has been studied and the decomposition steps have been correlated with the proper evolved or decomposed products.

Studies on Some Metal Chelates of 8-Hydroxy-Quinoline-5-Sulphonylhydrazide

Abstract Cu(II), Zn(II), Cd(II), Pb(II) and UO2(II) complexes of 8-hydroxyquinoline-5-sulphonylhydrazide (QSH) have been investigated. The formation, stoichiometry and stability of the complexes have been tested in solution using electronic spectral measurements and conductometric titrations. Characterization of the isolated solid complexes has been performed on the basis of elemental analysis, electronic and IR spectral data as well as polarographic measurements. It is concluded that the ligand acts as a monobasic ON bidentate ligand. The different bands observed in the electronic spectra of the ethanolic solution of the complexes have been assigned to the L + MCT and d-d electronic transitions.