scholarly journals Spectroscopic studies of benzoxazole-2-thione complexes. Derivatives of cobalt(II) and nickel(II) halides

1976 ◽  
Vol 54 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Carlo Preti ◽  
Giuseppe Tosi
Keyword(s):  
Magnetic Susceptibility ◽  
Ir Spectra ◽  
Electronic Spectra ◽  
Spectroscopic Studies ◽  
Ligand Field ◽  
Conductivity Measurements ◽  
Derivatives Of ◽  
Ligand Field Parameters ◽  
Cobalt And Nickel

The preparation of some complexes of benzoxazole-2-thione with halides of cobalt(II) and nickel(II) is reported. The complexes of cobalt(II) and nickel(II) are tetrahedral of the type ML2X2 with the exception of NiLBr2. The complexes have been studied by means of magnetic susceptibility measurements, infrared and far ir spectra, electronic spectra, and conductivity measurements. The ligand behaves as monodentate N-bonded. The various ligand field parameters, Dq, B′, and β show about 60 and 80% of covalency in the cobalt(II) and nickel(II) complexes respectively and suggest a medium strong ligand field. The spectroscopy parameters of cobalt and nickel derivatives confirm the presence of CoN2X2 and NiN2X2 chromophores.

Infrared and Electronic Spectral Studies of Cobalt(II) and Nickel(II) Complexes of N-Allyl Urea and N-Allyl Thiourea

1972 ◽  
Vol 50 (16) ◽  
pp. 2603-2609 ◽  
Author(s):  
P. P. Singh ◽  
I. M. Pande
Keyword(s):  
Magnetic Susceptibility ◽  
Electronic Spectra ◽  
Electrical Conductance ◽  
Spectral Studies ◽  
Ligand Field ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Halide Complexes ◽  
Ligand Field Parameters ◽  
Allyl Thiourea

Complexes of N-allyl urea (NAU) and N-allyl thiourea (NATU) with cobalt (II) and nickel (II) halides and perchlorates have been prepared and characterized by electrical conductance, magnetic susceptibility, infrared and electronic spectra. Infrared spectra suggest coordination in NAU through oxygen and in NATU through nitrogen. The electronic spectra and magnetic susceptibility data indicate tetrahedral and octahedral stereochemistry for cobalt (II) and nickel (II) halide complexes, respectively. The various ligand field parameters Dq, B′, and β calculated for these complexes show about 25 and 11% covalency for Co (II) and Ni (II), respectively, and suggest a weak ligand field.

Transition metal complexes of deprotonated 2-mercaptobenzoxazole. Study of the thiol–thioketo form equilibrium

1977 ◽  
Vol 55 (8) ◽  
pp. 1409-1414 ◽  
Author(s):  
Carlo Preti ◽  
Giuseppe Tosi
Keyword(s):  
Magnetic Susceptibility ◽  
Ir Spectroscopy ◽  
Transition Metal ◽  
Chemical Analysis ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Electronic Spectra ◽  
Ligand Field ◽  
Ligand Field Parameters

Complexes of 2-mercaptobenzoxazole (mbo) with Zn(II), Cd(II), Hg(II), Cu(I), Ag(I), Au(I), Ni(II), Pd(II), Pt(II), Co(II), Rh(III), and Ir(III) were prepared and characterized. Their structures have been assigned on the basis of chemical analysis, ir and far ir spectroscopy, electronic spectra, and magnetic susceptibility measurements. The ligand always bonds through both the sulphur and the nitrogen heteroatoms. The ligand field parameters have been evaluated and are in keeping with the proposed structures confirming the presence of MS2N2 and MS3N3 chromophores.

scholarly journals Synthesis, characterization and spectroscopic studies of the dihydrobis(1,2,3-benzotriazolyl)borate anion and its complexes with MCl2·py2

2006 ◽  
Vol 71 (11) ◽  
pp. 1137-1145 ◽  
Author(s):  
Khwaja Siddiqi ◽  
Ahmad Umar ◽  
Shahab Nami ◽  
Sadaf Khan
Keyword(s):  
Sodium Borohydride ◽  
Elemental Analysis ◽  
Spectroscopic Studies ◽  
Molar Conductance ◽  
Ligand Field ◽  
Conductivity Measurements ◽  
Ligand Field Parameters

The preparation of sodium dihydrobis(1,2,3-benzotriazolyl)borate was realised by refluxing one mole of sodium borohydride with two moles of 1,2,3-benzotriazole in toluene over a period of 12 h. Its complexes with MCl2?py2 [where M= Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and py = Pyridine] were characterized by elemental analysis as well as magnetic, spectroscopic and conductivity measurements. On the basis of these studies, it is proposed that the geometry of all the complexes is octahedral. The ligand field parameters 10 Dq, B and ? show extensive overlap between the M-L orbital. The molar conductance of 10-3Msolutions of the complexes in DMSO suggest them to be non-ionic in nature.

Donor properties of 2-aminothiazole and 2-acetylaminothiazole towards cobalt(II) halides

1974 ◽  
Vol 27 (3) ◽  
pp. 509 ◽  
Author(s):  
PP Singh ◽  
AK Srivastava
Keyword(s):  
Magnetic Susceptibility ◽  
Infrared Spectra ◽  
Electronic Spectra ◽  
Point Group ◽  
Carbonyl Oxygen ◽  
Ligand Field ◽  
Tetrahedral Configuration ◽  
X Ray ◽  
Ligand Field Parameters

Molecular addition complexes of the type CoL2X2 (X = Cl, Br, I and L = 2-aminothiazole and 2-acetylaminothiazole) have been prepared and studied by infrared spectra, electronic spectra, magnetic susceptibility and X-ray powder data. Infrared and electronic spectra suggest coordination through exocyclic nitrogen in 2-aminothiazole and through carbonyl oxygen in 2-acetylaminothiazole. The complexes have tetrahedral configuration and belong to the C2" point group. Ligand field parameters Dq, B' and β show more covalency in 2-aminothiazole complexes than in 2-acetylamino-thiazole complexes and suggest a weak ligand field for both the ligands.

N,N′-Bis(phenylaminomethyl)parabanic add as a complexing agent. Complexes of some bivalent first row transition metals

1977 ◽  
Vol 55 (2) ◽  
pp. 344-349 ◽  
Author(s):  
Antonio Costantino Fabretti ◽  
Gian Carlo Franchini ◽  
Carlo Preti ◽  
Giuseppe Tosi
Keyword(s):  
Nmr Spectra ◽  
Far Infrared ◽  
Complexing Agent ◽  
Ligand Field ◽  
Conductivity Measurements ◽  
B Values ◽  
Nitrogen Bonds ◽  
Ligand Field Parameters ◽  
Far Infrared Spectra ◽  
Metal Ligand

The preparation of some complexes of N,N′-bis(phenylaminomethyl)parabanic acid with halides of cobalt(II), nickel(II), and copper(II) is reported. The complexes of the type MLX2 seem to have pseudo-tetrahedral and pseudo-octahedral symmetry. The complexes have been studied by means of magnetic susceptibility measurements, infrared and far infrared spectra, electronic and nmr spectra, and conductivity measurements. The ligand behaves as bidentate N-bonded. The various ligand field parameters, Dq, B', and β have been evaluated. The B' values suggest a strong covalency in the metal–ligand σ bond and Dq values show a medium strong ligand field. The presence of metal–nitrogen bonds is suggested. The possible stereochemistries of the complexes are discussed in the light of the experimental results.

scholarly journals Synthesis, Spectral, Magnetic and Thermal Studies of the Complexes of CoIIand NiIIWith Some Bidentate and Tridentate Hydrazone Ligands

2005 ◽  
Vol 2 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Chetan K. Modi ◽  
Ashwin S. Patel ◽  
Bharat T. Thaker
Keyword(s):  
Magnetic Moments ◽  
Picolinic Acid ◽  
Thermal Studies ◽  
Acid Hydrazide ◽  
Spectral Studies ◽  
Ligand Field ◽  
Conductivity Measurements ◽  
Octahedral Structure ◽  
Hydrazone Ligands ◽  
Ligand Field Parameters

The reaction of Co(NO3)2.6H2O and Ni(NO3)2.6H2O with hydrazones derived from 1-phenyl-3-methyl-4-acyl-5-pyrazolone (where acyl = acetyl, propionyl, butyryl and benzoyl) with 2-picolinic acid hydrazide have been studied and characterized on the basis of elemental analysis, magnetic moments, molar conductivity measurements, IR and electronic spectral studies and thermogravimetric analysis. Various ligand field parameters have been calculated. Electronic spectral data and the magnetic moment values suggest an octahedral structure for all cobalt(II) and nickel(II) complexes.

scholarly journals Biological Active Cobalt(II) and Nickel(II) Complexes of 12-Membered Hexaaza [N6] Macrocyclic Ligand Synthetic and Spectroscopic Aspects

2010 ◽  
Vol 7 (4) ◽  
pp. 1238-1245 ◽  
Author(s):  
Umendra Kumar ◽  
Sulekh Chandra
Keyword(s):  
Thermal Analysis ◽  
Magnetic Susceptibility ◽  
Metal Ion ◽  
Macrocyclic Ligand ◽  
Pathogenic Fungi ◽  
Spectroscopic Studies ◽  
Molar Conductance ◽  
Octahedral Geometry ◽  
Conductivity Measurements ◽  
Macrocyclic Schiff Base

New cobalt(II) and nickel(II) complexes of 12-membered macrocyclic Schiff - base ligand containing thiosemicarbazone moiety as a part of ring have been prepared having general composition [MLX2] where M = Co(II) or Ni(II), L=3,4,9,10–tetra-2-furanyl-1,2,5,6,8,11- hexaazacyclododeca-7,12- dithione - 2,4,8,10 – tetraene, X = Cl-, NO3-, NCS-. The complexes have been characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, spectral (IR, electronic, EPR) techniques and thermal analysis. Spectroscopic studies suggested a six coordinated octahedral geometry for all the complexes. The IR spectra of complexes suggest that ligand is coordinated to the metal ion through its four imines nitrogen. Conductivity measurements supported the non electrolytic nature of the complexes. The antifungal activities of complexes have been studied against a number of pathogenic fungi under laboratory conditions. The complexes showed good antifungal results. Thermal analysis of reported complexes suggests the absence of water molecule either in or outside the coordination sphere.

Metal complexes of tridentate hybrid ligands. I. Cobalt and nickel conlplexes of ligands containing the donor sequence As-N-O

1969 ◽  
Vol 22 (11) ◽  
pp. 2315 ◽  
Author(s):  
B Chiswell ◽  
KW Lee
Keyword(s):  
Metal Complexes ◽  
Electronic Spectra ◽  
Weak Field ◽  
Magnetic Data ◽  
Conductivity Measurements ◽  
Hybrid Ligands ◽  
Cobalt And Nickel

The interaction of the new tridentate ?hybrid? ligand, N-o- dimethylarsino-phenylsalicylaldimine (As-N-O), with cobalt(II) salts leads to the formation of cationic octahedral cobalt(III) complexes of the type [Co(As-N-O)2]+. No cobalt(II) complex entities containing the ligand could be isolated. With nickel(II) salts three types of octahedral complexes were obtained: (a) [Ni(As-N-O)2],H2O, (b) Ni(As-N- O)X,-xH2O (X = Cl, Br, or NCS), (c) [Ni2(As-N-O)3ClO4]. Electronic spectra, conductivity measurements, and magnetic data have been used to determine the structure of the complexes isolated. The ?hybrid? ligand appears to operate overall as a relatively weak field ligand.

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