K. K. Narang

Synthesis and characterization of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with acetylacetone bis-benzoylhydrazone and acetylacetone bis-isonicotinoylhydrazone

SummaryAcetylacetone bis-benzoylhydrazone (PhCONHN=CMe)2 CH2(LH2) and acetylacetone bis-isonicotinoylhydrazone (NC5H4CONHN=CMe)2CH2(L′H2) complexes of the types [ML] and [ML′] (M = CoII, NiII, CuII or ZnII) have been prepared and characterized. All the complexes are non-electrolytes and the cobalt(II) complexes are lowspin, the nickel(II) complexes are diamagnetic and the copper(II) complexes are paramagnetic. The ligands chelate via two C=N groups and two deprotonated enolate groups. The e.s.r. spectra of the copper(II) complexes indicate a tetragonally distorted dimeric structure. The X-ray diffraction parameters for [CoL] and [NiL′] correspond to a tetragonal crystal lattice.

Synthesis, characterization and physicochemical studies of some copper(II) tetrathiocyanato dithallate(I) complexes with hydrazides and hydrazones

Abstract Copper(II) complexes of the type Cu[Tl(SCN2]2·L [where L = benzoic hydrazide (BH), isonicotinic hydrazide (INH), salicyclic hdyrazide (SH), anthranilic hydrazide (AH), p-hydroxybenzoic hydrazide (PHBH), p-aminobenzoic hydrazide (PABH) and their isopropanone derivatives, i.e. isopropanone benzoylhdyrazone (IBH), isopropanone isonicotinoyl hydrazone (IINH), isopropanone salicyloylhydrazone (ISH) and isopropanone anthranoylhydrazone (IAH)] were synthesized and characterized. All the complexes are non-electrolytes, and dissociate in H2O, C2H5OH, CH3CN and CH3COCH3. They are either coordinated through CO and NH2 groups of the hydrazide or CO and CN of the hydrazone ligands. The electronic and ESR spectra suggest a planar geometry for Cu[Tl(SCN2]2 and a tetragonally distorted octahedral structure for all other complexes. The X-ray diffraction parameters for some of the complexes correspond to a tetragonal crystal lattice.

E.S.R. STUDIES ON ACYLHYDRAZINE AND HYDRAZONE COPPER(II) SULFATE COMPLEXES

SummaryCuII complexes of the [CuL2(SO4)]·nH2O and [CuL′(SO4)(H2O)2]·nH2O type, where L = benzoylhydrazine (PhCONHNH2; BH) or iso-propanone benzoylhydrazone (PhCONHN:CMe2; IBH), L′= iso-nicotinoylhydrazine (NC5H4CONHNH2; INH) or isopropanone iso-nicotinoylhydrazone (NC5H4CONHN: CMe2; IINH); n = 0–2, were prepared and characterized by elemental analyses, molar conductances, and electronic, e.s.r. and i.r. spectral measurements. The electronic and e.s.r. spectra suggest a tetragonally distorted octahedral geometry in the solid state as well as in DMSO solution. The e.s.r. data also reveal an axial symmetry for most of the complexes in the solid state and in DMSO solution at 300 and 77 K, while the complex of IBH is isotropic at 300 K. The ΔMs = 2 transition observed for this complex suggests that it is a dimer. BH and INH bond to CuII through the C-O and NH2 groups, whereas IBH and IINH bond through C-O and C-N groups.

Synthesis and Spectral Studies of Zinc Chloride Complexes with Some Acetophenone and 4-Hydroxy-Acetophenone Acylhydrazones

Abstract Zinc(II) complexes of the types [Zn(L)nCl2(H2O)2] and [Zn(L)nCl2]H2O [n = 1 or 2, m = 1,2 and 4 and L = acetophenone or 4-hydroxyacetophenone acylhydrazones of benzoic, isonicotinic, salicylic and 4-aminobenzoic acid hydrazides and oxalic, malonic and succinic acid dihyrazides] were synthesized and characterized by elemental analyses, dehydration studies, molar conductance, infrared. NMR and electronic spectral data and powder X-ray diffraction studies. The ligands coordinate through >C˭O and >C˭N groups to the metal ions. The water molecules are in the coordination sphere in case of the 1:1 (metaUigand) complexes and the hydrazones from the dihydrazides act as quadridentate ligands bonding through the >C˭O and >C˭N groups. The zinc complexes of acetophenone benzoyl hydrazone and acetophenone oxaloyl dihydrazone, [ZnL2Cl2·H2O, cryastallize in an orthorhombic unit lattice.

Synthesis, Characterization, Thermal Studies and Biological Activity of Iron(III) Complexes with some Acylhydrazines

Abstract Iron(III) complexes of the type [FeL2 X2]x-nH2O, where L = benzoylhydrazine (BH), isonicotinoylhydrazine (INH), sali-cyloylhydrazine (SH), oxaloyldihydrazine (ODH) and malonoyl-dihydrazine (MDH); X = Cl–, NO3, SCN– and 1/2 SO4 2-; n =0−3, were prepared and characterized with the help of elemental analyses, molar and solid state conductance, thermal, magnetic, infrared and electronic spectral studies. The complexes are highly insoluble in common organic solvents, decompose above 200°C and are spin free octahedral. The ligands coordinate to the metal atom through >C=O and NH2- The complexes show multi-step exothermic decomposition patterns. The ligands as well as their complexes show moderate antifungal and antibacterial activity.

Polymeric complexes of bivalent transition metal ions with 2-hydroxy-1-naphthaldehyde oxaldihydrazone and 2-hydroxy-1-naphthaldehyde malondihydrazone

SummaryPolymeric complexes prepared by solid-solution reactions, from 2-hydroxy-1-naphthaldehyde oxaldihydrazone (HNODH) and 2-hydroxy-1-naphthaldehyde malondihydrazone (HNMDH), had the empirical composition M(L-2H)·nH2O where M=FeII, MnII, CoII, NiII, CuII, ZnII, CdII and HgII; L=HNODH, HNMDH andn=0,1, 2. The complexes, which are intensely coloured and insoluble in common organic solvents, were characterized by elemental analysis, magnetic susceptibility, electronic and i.r. spectral data. The absence of anions indicates that the ligands which bind the metal ions from the hydroxyl and the imino groups have been deprotonated.

Complexes of Zn(II), Cu(II), Ni(II) and Co(II) Tetrathiocyanato Mercurates(II) with Hydrazides and Their Biological Activity

Abstract A new series of bimetallic tetrathiocyanate complexes of the type MM′(SCN)4.L, M = Zn(II), Cu(II), Ni(II), Co(II), M′ = Hg and L = benzoylhydrazide (BH), oxaldihydrazide (ODH) and malondihydrazide (MDH) have been synthesized in dilute ethanolic medium. The 1:1 metal:ligand complexes, which have been characterized by elemental analysis, magnetic moment data, electronic and infrared spectra, are insoluble in water as well as common organic solvents and decompose above 250°C without melting. The ligands act as bidentate coordinating species in the complexes. Some of these bimetallic complexes have been tested against Escherichia coli and Klebsillea pneumoniae bacteria and Aspergillus flavus, Penicillium sp. fungi, and were found to be biologically active.

5-FLUOROURACIL AND 5-FLUOROURACIL-HISTIDINE COMPLEXES WITH ALIII, CRIII AND FEIII IONS AND THEIR ANTITUMOUR ACTIVITY

Abstract Complexes of the type [M(L-H)(OH)Cl], [Cr(L-H)(H2O)2(OH)Cl] and [M′(L-H)(L′-H)(H2O)Cl], where L = 5-fluorouracil; L′ = histidine (HISD); M = AlIII or FeIII and M′ = AlIII, CrIII or FeIII were synthesized and characterized. The complexes are insoluble in water and common organic solvents. 5-Fluorouracil is coordinated to the metal ion through the O atom of C4 = O and the N atom of N1 while histidine coordinates through the O atom of −COO− and the N atom of −NH2 groups. The μeff values, electronic spectral bands and ESR spectra suggest a polymeric 6-coordinate spin free octahedral stereochemistry for CrIII and FeIII complexes. The in vivo antitumour effect of 5-fluorouracil and its complexes was examined on C3H/He mice against P815 murine mastocytoma. As evident from their T/C values CrIII and FeIII complexes display significant and higher antitumour activity compared to 5-fluorouracil while the AlIII complexes show lower activity. The in vitro results of the complexes on the same cells indicate that CrIII and FeIII complexes show higher inhibition on 3H-thymidine and 3H-uridine incorporation in DNA and RNA replication, respectively.

Synthesis and Spectral Studies of Copper(II) Sulfate Complexes with Some Acetophenone Acylhydrazones

Abstract The copper(n) complexes of the type [CuSO4(L)(H2O)2].nH2O and [CuSO4(L1)].nH2O where L = acetophenone-benzoylhydrazone (ABH), isonicotinoylhydrazone (AINH), -salicyloylhydrazone (ASH), -p-aminobenzoyl (APABH) and L1 = acetophenone oxaloyldihydrazone (AODH), -malonoyl-dihydrazone (AMDH) and -succinoyldihydrazone (ASDH) and n = 0, 1 or 2, were prepared and characterized by elemental analyses, dehydration studies, molar conductance, magnetic moments, electronic, ESR and infrared spectra. The electronic and ESR spectra indicate a six-coordinate distorted octahedral geometry for all of the complexes in the solid state. ESR spectral data reveal an axial symmetry for the ABH, AINH and APABH complexes whereas the AODH, AMDH and ASDH complexes are isotropic. Most of the ligands are bidentate, coordinating through the >C[dbnd]O and >C[dbnd]N groups to the metal ion except AMDH and ASDH which act as quadridentate ligands bonding through two >C[dbnd]O and two >C[dbnd]N groups.

Synthesis and studies of some bivalent transition metal complexes with acylhydrazones

Abstract Complexes of 3-hydroxy-2-naphthaldehyde benzylhydrazone (H 2 nabh) and 3-hydroxy-2-naphthaldehyde salicyloylhydrazone (H 3 nash) of the empirical composition M(L2H)· n H 2 O [M = manganese(II), iron(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), mercury(II), L = H 2 nabh, H 3 nash and n = 0, 1, 2] were prepared and characterized by elemental analyses, magnetic susceptibility, electronic and infrared spectral data. Zinc(II) and cadmium(II) complexes were also studied by 13 C, 1 H NMR and the Cu(nabh)·H 2 O complex by transmission electron microscopy. The complexes are coloured and highly insoluble in common organic solvents. Absence of the original anion in the complexes indicates deprotonation of the ligands (H 2 nabh and H 3 nash) which bind the metal ions from the OH and the CN groups.