Mohsen M. Mostafa

Metal complexes of schiff's base derived from salicoylhydrazine and biacetylmonoxime

Biacetylmonoxime-salicoylhydrazone (BMSH) complexes of the types [Hg(BMSH)Cl2] and [M(BMSH-H)2], where M = Cu(II), Co(II), Ni(III), Mn(II), Zn(II), Cd(II) and UO2(VI), have been prepared and characterized by conventional chemical and physical measurements. The IR spectra show that the ligand usually coordinates via carbonyl oxygen (CO), azomethine nitrogen (CNl) and phenolic OH with replacement of hydrogen by metal ions but acts as a bidentate molecule coordinating through (CO) and (CNl) in the Hg(II) complex. The magnetic and spectral data of the Co(II) and Ni(II) complexes support octahedral stereochemistry, whilst tetragonally distorted octahedral geometry is suggested for the Cu(II) complex.

Copper(II), cobalt(II), nickel(II) and mercury(II) complexes of 1,4-diphenylthiosemicarbazide

SummaryThe preparation and characterization of CuII, CoII, NiII and HgII complexes containing 1,4-diphenylthiosemicarbazide (DPhTSC) of the type [Cu(DPhTSC-H)X.H2O]nH2O (X= Cl, Br or Ac; n=0 or 1) · [M(DPhTSC-H)2yH2O] (M=CoII or NiII; y=0 or 1) and [Hg(DPhTSC)Cl2]2 H2O and [Cu(D-PhTSC)2SO4]H2O are reported. The stereochemistry of the complexes have been studied with the help of magnetic and electronic measurements. The anomalous magnetic moments observed in all cases have been explained. The i.r. spectral studies have been used to determine the bonding sites in the complexes.

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.

Complexes of Cu(II), Co(II), Ni(II), Cd(II) and Hg(II) halides with hydrazones derived from girard T and chromone

Abstract Complexes of chromone Girard T (Ch.G.T) with Cu(II), Co(II), Ni(II), Cd(II) and Hg(II) have been synthesized and characterized by elemental analysis, pH titrations, conductance measurements, uv, visible and IR spectral studies.

Synthesis and spectroscopic studies of 2,5-hexanedione bis(isonicotinylhydrazone) and its first raw transition metal complexes

New VO(2+), Mn(2+), Co(2+), Ni(2+) Cu(2+) and Zn(2+) complexes of 2,5-hexanedione bis(isonicotinylhydrazone) [H(2)L] have been synthesized and characterized. The analyses confirmed the formulae: [VO(L)].H(2)O, [Mn(2)(H(2)L)Cl(2)(H(2)O)(6)]Cl(2), [Co(L)(H(2)O)(2)].2H(2)O, [Ni(HL)(OAc)].H(2)O, [Cu(L)(H(2)O)(2)].2H(2)O, [Cu(L)].2H(2)O and [Zn(L)(H(2)O)(2)]. The formulae of [Ni(HL)(OAc)].H(2)O, [Zn(L)(H(2)O)(2)] and [Mn(2)(H(2)L)Cl(2)(H(2)O)(6)]Cl(2), are supported by mass spectra. The molecular modeling of H(2)L is drawn and showed intramolecular hydrogen bonding. The ligand releases two protons during reaction from the two amide groups (NHCO) and behaves as a binegative tetradentate (N(2)O(2)); good evidence comes from the (1)H NMR spectrum of [Zn(L)(H(2)O)(2)]. The ligand has a buffering range 10-12 and pKs of 4.62, 7.78 and 9.45. The magnetic moments and electronic spectra of all complexes provide a square-planar for [Cu(L)].2H(2)O, square-pyramidal for [VO(L)].H(2)O and octahedral for the rest. The ESR spectra support the mononuclear geometry for [VO(L)].H(2)O and [Cu(L)(H(2)O)(2)].2H(2)O. The thermal decomposition of the complexes revealed the outer and inner solvents where the end product in most cases is metal oxide.

New metal complexes derived from 4-benzamido-1-diacetylmonoxime-3-thiosemicarbazone with some transition metal ions

SummaryDivalent cobalt, nickel, copper, zinc, cadmium and mercury salts react with 4-benzamido-1-diacetylmonoxime-3-thiosemicarbazone (BDTS) forming two types of complexes,i.e., [M(BDTS)X2 · nH2O]YH2O (M = CoII, NiII, ZnII, CdII or HgII; X = Cl, Br or 1/2 SO4 and n=0–1) and [Cu(BDTS)X]2 · nH2O (X=Cl, Br or 1/2 SO4 and n=0–1). The complexes were identified and characterized on the basis of partial chemical analysis, molar conductance, magnetic moment and spectral (visible, n.m.r., i.r.) studies. I.r. spectral studies suggest that BDTS is tridentate and coordinatesvia the azomethine groups (hydrazone and oxime residue) as well as the thioketo-group with cobalt and nickel but is bidentate coordinatingvia the azomethine groups with the remaining metal ions. Further, the ligand behaves as a reducing agent towards CuII salts forming diamagnetic CuI complexes.

Mono- and binuclear Schiff base complexes derived from glycine, 3-acetylpyridine and transition metal ions

Binuclear Schiff base complexes derived from glycine (Gly) and 3-acetylpyridine (3-APy) in the presence of M(OAc)2 [M = CoII, NiII, CuII, ZnII and CdII] have been synthesized. The role of pH in promoting the condensation of glycine and 3-acetylpyridine, as well as the substitution of acetates by hydroxide ion, has been discussed. Also, the reaction of glycine with 3-acetylpyridine in the presence of MCl2 [M = CoII and NiII] and MCl3 [M = FeIII and CrIII] yields mono- and/or binuclear complexes containing both of glycine and 3-acetylpyridine without condensation. Both types of complex were isolated and characterized by chemical analysis, conductance, spectral (u.v.–vis., i.r., and 1H-n.m.r.), magnetic and thermal 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.

Bivalent metal complexes ofp-methyl- andp-methoxybenzoylhydrazone oximes

SummaryBivalent metal complexes ofp-chloro-,p-methyl- andp-methoxybenzoylhydrazone oximes (H2BMCB, H2BMMB or H2BMTB=H2L), [M(H2L)Cl2]. nH2O (M=ZnII, CdII or HgII, n=0 or 1; [M(H2L)Cl2] (M=ZnII or CdII); [M(HL)2(H2O)n]. YH2O (M=CoII, CuII, ZnII or UVIO2, n=0–2); [Ni(H2BMCB)(H2O)3]Cl2, [Ni(BMMB)(H2O)]2 and [Ni(BMTB)(H2O)]2, were synthesized by conventional physical and chemical measurements. I.r. spectra show that the ligands are bidentate or tridentate. Spectral, magnetic and molecular weight measurements suggest that cobalt(II) and nickel(II) have monomeric octahedral geometry when derived from H2BMCB, a dimeric square planar geometry for nickel(II) and monomeric square planar geometry for cobalt(II) for those isolated from H2BMMB or H2BMTB. Also, a monomeric distorted octahedral structure is proposed for copper(II) complexes derived from the ligands under investigation.

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.