Magdy M. Bekheit

Synthesis of Some Transition Metal Complexes Derived from 1-Valeroyl-4-phenyl-3-thiosemicarbazide

Abstract The synthesis and characterization of metal complexes of some dipositive metal ions with 1-valeroyl-4-phenyl-3-thiosemicarbazide (VTSC) is reported. The data of elemental analysis, molar conductivities, magnetic measurments and spectral (i.r., visible) studies have been used to elucidate the structure of the complexes. I.r spectra show that VTSC acts as a bidentate ligand and coordinates via 2NH and the enolic carbonyl oxygen (=C-OH) of the hydrazide moiety with the displacement of a hydrogen atom from the latter group. The values of molar conductivities in DMF indicate the non-electrolytic nature of all metal chelates. A tetrahedral structure is proposed for [Co (VTSC-H) Ac], square-planar for [Ni (VTSC-H) Ac] and [Cu (VTSC-H) Ac]H2O complexes, and octahedral for [Ni (VTSC-H)2. 2H2O]2H2O and [Co (VTSC-H)2.2H2O]2H2O complexes according to the data of magnetic and electronic spectral measurments.

Synthesis and Structural Studies of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) Chelates Derived From Semicarbazide and Thiosemicarbazide Derivatives

Abstract The synthesis and characterization of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) chelates containing 1-anthranyl-4-phenyl-3-semicarbazide (APSC) and/or 1-anthranyl-4-phenyl-3-thiosemicarbazide (APTSC) are reported. The chelates have been characterized on the basis of elemental analyses, spectra (NMR, IR, visible), magnetic moments, conductivities and molecular weight measurements. The values of molar conductivities in DMP or DMSO indicate the non-ionic nature of all metal chelates. A tetrahedral structure is proposed for the Ni(II) chelates, square-planar for the Cu(II) chelates and tetrahedral or octahedral for the Co(II) chelates according to the data of magnetic measurements and electronic spectra. The ligands (APSC, APTSC) behave in a bidentate manner toward the metal ions, but with different coordination sites. 1HNMR spectra of the ligands and the diamagnetic chelates are discussed. The chelates have a monomeric or a polymeric nature.

Synthesis, Spectral, Magnetic and Thermal Studies of 1-Phenylacetyl-4-Phenyl-3-Thiosemicarbazide Complexes

Abstract Complexes of 1-phenylacetyl-4-phenyl-3-thiosemicarbazide (H2PAPTS) with Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II) and Hg(II) have been prepared and characterized on the basis of chemical, thermal (TG, DTA) analyses, spectral (IR, 1H NMR, UV-Vis.), magnetic moment and molar conductivity measurements. IR and 1H NMR spectral data show that H2PAPTS behaves as a neutral bidentate, mononegative bidentate or binegative tetradentate ligand. All the reported complexes are non-electrolytes and different stereochemistries are proposed for the Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Pd(II) complexes according to their magnetic and spectral measurements. The thermal decomposition of the complexes (Co(HPAPTS)(OAc)] and [Cd(HPAPTS)(OAc)(H2O)2] suggests a mechanism for their degradation. The [Fe(PAPTS)Cl(H20)] complex was found to function as a one-electron stoichiometric oxidant towards primary and secondary alcohols.

Ligational behaviour of biacetylmonoxime nicotinoyl hydrazone (H2BMNH) towards transition metal ions

SummaryThe synthesis and characterization of MnII, CoII, NiII, CuII, ZnII, CdII UO22+, CrIII and FeIII complexes of biacetylmonoxime nicotinoyl hydrazone (H2BMNH) are reported. Elemental analysis, molar conductance, magnetic moment and spectral (i.r., visible and n.m.r.) measurements have been used to characterize the complexes. I.r. spectral data show that the ligand behaves in a bidentate and/or tridentate manner. An octahedral structure is proposed for the MnII, NiII, CrIII and FeIII complexes, while a square-planar structure is proposed for both CoII and CuII complexes on the basis of magnetic and spectral measurements.

Synthesis and characterization of new metal complexes of thiosemicarbazone derived from 4-phenyl-3-thiosemicarbazide and chromone-3-carboxaldehyde

SummaryThe reaction between chromone-3-carboxaldehyde-4-phenylthiosemicarbazone (HCPT) and some hydrated metal salts of CoII, NiII and CuII give complexes of the type [Cu(HCPT)Cl2],[Cu(CPT)BrH2O],[Cu(CPT)2]·2H2O, [Ni(CPT)2(H2O)2]·2H2O, [Co(CPT)2(OAc)] and [Co(CPT)2(H2O)2]X·2H2O (where X=Cl or Br). The metal complexes were characterized by elemental analyses, molar conductivities, and spectal (i.r. and visible) and magnetic studies. I.r. spectra show that the HCPT coordinates in the thione or thiol form and behaves in a bidentate manner. Also, HCPT behaves as an oxidizing agent towards CoII forming diamagnetic CoIII complexes. An octahedral structure is proposed for both CoIII and NiII complexes, while a square-planar structure is proposed for CuII complexes on the basis of magnetic and spectral measurements.

Structural Studies of 1-Isatin-4-phenyl-3-thiosemicarbazone and 1 - (α-) Furyl-4-phenyl-3-thiosemicarbazone Complexes

Abstract New metal complexes derived from 1-isatin-4-phenyl-3-thiosemicarbazone (IPTS) and 1-(α-) furyl-4-phenyl-3-thiosemicarbazone (PPTS) with Ni(II), Co(II), Cu(II) and Cd(II) have been synthesized and characterized on the basis of elemental analyses, magnetic moments, molar conductivities and spectral (NMR, Visible, IR) measurements. IR spectra show that IPTS coordinates in a tridentate manner via CN, CO and CS groups, while FPTS acts as a bidentate ligand coordinating via CN and CO groups. Magnetic and spectral studies suggest a square-planar structure for the Cu(II) and Ni(II) complexes which are derived from FPTS and a low-spin octahedral structure for [Co(FPTS-H)3]· 2H2O. On the other hand, octahedral structures are proposed for the complexes of Ni(II) and Cu(II) that are derived from IPTS and a low-spin octahedral structure for [Co(IPTS-H)2]. 1HNMR spectra of the ligands and the diamagnetic complexes are discussed.

Spectral, thermal and magnetic studies of biacetylmonoxime isonicotinoylhydrazone complexes

Abstract The synthesis and characterization of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and UO2+2 complexes of biacetylmonoxime isonicotinoylhydrazone (BMINH) are reported. Elemental-analysis, magnetic, thermal and spectral (IR, visible and NMR) measurements have been used to characterize the complexes. IR spectral data show that the ligand behaves in a bidentate and/or tridentate manner. An octahedral structure is proposed for the Ni(II) complexes, while a square-planar structure is proposed for both Co(II) and Cu(II) complexes, on the basis of magnetic and spectral measurements.

Ligational behaviour of biacetylmonoxime-o-aminobenzoylhydrazone (H2BMAB) towards some dipositive metal ions

SummarySeveral new dipositive metal complexes with the hydrazoneoxime, derived from biacetylmonoxime ando-aminobenzoylhydrazine, have been synthesized and their structures elucidated by elemental analyses, conductivities, spectra (visible, i.r. and n.m.r.), magnetic and molecular weight measurements. The i.r. spectra show that the ligand, (H2BMAB), behaves in a bidentate and tridentate manner. The stereochemistry of the cobalt(II), nickel(II) and copper(II) complexes is discussed. The cobalt(III) complex, [Co(BMAB)OH]n, has also been isolated and characterized by conventional physical and chemical measurements and on the basis of molecular weight determination is probably a polymer, whereas the remaining complexes are monomers. I.r. and n.m.r. data suggest that the cobalt(III) complex contains hydroxo-bridge linking.

Synthesis and Studies of Some Bivalent Metal Complexes of 1-p-Chlorobenzoyl-4-phenyl-3-thiosemicarbazide

Abstract The synthesis, spectra (IR, Visible), magnetic susceptibilites and conductance measurements of a series of bivalent metal complexes of the general formula [M(L-H)2]. nH2O(M = Mn(II), Ni(II), Cu(II) and Cd(II); L=p-CPTS = 1-p-chlorobenzoyl-4-plenyl-3-thiosemicarbazide and n = 1 or 2), [M(L-H)X- nH2O] (M = Co(II), Cu(II); X=Cl, Ac and n = O-3), [Co(L-H)Cl-DMF] (DMF=dimethylformamide) and [HgLCl2] are described. 1H NMR spectra of the ligand and the diamagnetic complexes are discussed. The infrared spectra show that the ligand behaves in a bidentate manner coordinating via the (1NH) and the thiocarbonyl sulphur atoms either in the keto or in the enol form to give five membered ring around the metal ion. Both magnetic and the spectral studies are in favour of an octahedral structure for the brown Co(II) complex, [Co(L-H)Cl (H2O)3], which changes to a green tetrahedral Co(II) complex, [Co(L-H)Cl-DMF], on dissolution of the brown complex in DMF. Also, the stereochemistry of Ni(II)and Cu(II) complexes ha...

Ligational Behaviour of 1-Picolinoyl–4-phenyl–3-thiosemicarbazide (H2PTS) Towards Some Transition Metal Ions

Abstract Complexes of 1-picolinoly-4-phenyl-3-thiosemicarbazide (H2PTS) with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and UO2(VI) have been synthesized and characterized on the basis of elemental analyses, molar conductivities, magnetic moment and spectral (IR and visible) studies. IR spectral data show that H2PTS behaves in a monoanionic bidentate or tetradentate and bianionic tetradentate manner. All complexes are non-electrolytes. An octahedral structure is proposed for the Cr(III), Mn(II), Fe(III), Co(II) and Ni(II) complexes, while a square-planar one is suggested for Cu(HPTS)Cl.H2O and Cu(PTS) according to the data of magnetic and electronic spectral measurements.