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.

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.

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.

Synthesis and structure of 4-methylpyridine complexes of cobalt(II) and nickel(II) hexafluorophosphate and hexafluoroarsenate

1978 ◽  
Vol 56 (7) ◽  
pp. 985-991 ◽  
Author(s):  
Raymond M. Morrison ◽  
Robert C. Thompson
Keyword(s):  
Magnetic Properties ◽  
Field Strength ◽  
Single Crystal ◽  
Infrared Spectra ◽  
Electronic Spectra ◽  
Preliminary Report ◽  
Ligand Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar

The complexes M(4mepy)4A2 and M(H2O)2(4mepy)8A2 (where M is Ni or Co and A is PF6 or AsF6) have been prepared and their electronic spectra and magnetic properties studied. A preliminary report is made of single crystal X-ray diffraction studies on Ni(H2O)2(4mepy)8(PF6)2, Co(H2O)2(4mepy)8(PF6)2, and Co(4mepy)4(PF6)2. All of the complexes have structures involving complex cations and non-coordinated anions, consistent with extremely weak ligating abilities for both PF6− and AsF6−. Cations identified and characterized are the squashed tetrahedral [Co(4mepy)4]2+ ion, the square planar [Ni(4mepy)4]2+ ion, and the tetragonal [Co(4mepy)4((4mepy)2H2O)2]2+and [Ni(4mepy)4((4mepy)2H2O)2]2+ ions. The ligand field strength of 4-methylpyridine is found to be indistinguishable from that of pyridine in these complexes. Infrared spectra are reported and infrared criteria for establishing the presence of non-coordinated anions in PF6− and AsF6− complexes are suggested.

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.

Some substituted urea and thiourea complexes of Co(II), Mn(II), and Cr(III)

1969 ◽  
Vol 47 (12) ◽  
pp. 2275-2282 ◽  
Author(s):  
Pakinam Askalani ◽  
R. A. Bailey
Keyword(s):  
Magnetic Susceptibility ◽  
Ligand Field ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Ligand Field Parameters ◽  
Substituted Urea

Complexes of Co(II), Mn(II), and Cr(III) with N-butylurea, N-methylthiourea, and N,N′-dimethylthiourea, and Cl−, Br−, NO3−, and ClO4− anions were prepared and characterized using infrared and visible spectroscopy, and magnetic susceptibility. The urea is bonded through oxygen, and the thioureas through sulfur in all cases. The Co–N-butylurea compounds are octahedral, mostly with CoL6X2 stoichiometries, but some compounds involving coordinated anions and possibly bridging butylurea ligands were found. The Co–thioureas are tetrahedral. Octahedral Cr(III) compounds of the type CrL3X3 and CrL6(ClO4)3 were prepared, and the CrS6 chromophore characterized. Mn(II)–butylureas are octahedral, while the thioureas show MnL6X2 and MnL4X2 stoichiometries. X-ray diffraction established some of the latter to be isostructural with the analogous tetrahedral Co(II) compounds. Ligand field parameters Dq and B have been evaluated for the Co(II) and Cr(III) compounds.

Spectral and Magnetic Properties of Dithiocyanato bis (Biguanide) Chromium(III) Thiocyanate

1974 ◽  
Vol 29 (7-8) ◽  
pp. 492-494 ◽  
Author(s):  
A. Syamal
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Infrared Spectra ◽  
Magnetic Moment ◽  
Electronic Spectra ◽  
Title Compound ◽  
Ligand Field ◽  
Octahedral Structure ◽  
Modified Method ◽  
Infrared Spectral

A reinvestigation of the title compound is reported. The compound has been prepared by a modified method and characterised by infrared spectra, electronic spectra and magnetic susceptibility measurements. The infrared spectral data suggest that the two coordinated thiocyanate ions are bonded to chromium(III) through N atoms rather than the S atoms. The complex exhibits two ligand field bands at 20410 and 26660 cm-1 due to the transitions 4A2g → 4T2g and 4A2g → 4T1g (F) respectively. Electronic spectral and magnetic moment data suggest that the complex has an octahedral structure with d2sp3 bonding.

The Coordination Chemistry of Phosphoryl Compounds Containing the — N(CH3)2 Group, Part VIII

1972 ◽  
Vol 27 (7) ◽  
pp. 759-763 ◽  
Author(s):  
M. W. G. De Bolster ◽  
W. L. Groeneveld
Keyword(s):  
Coordination Chemistry ◽  
General Formula ◽  
Ligand Field ◽  
Chemical Analyses ◽  
X Ray ◽  
Physical Measurements ◽  
Ligand Field Spectra ◽  
Chloride Adduct ◽  
Ligand Field Parameters ◽  
Group Part

A number of new solvates and adducts containing bisphenyldimethylaminophosphine oxide is reported. The solvates have the general formula M[(C6H5)2P(O)N(CH3)2]42+(anion-)2, in which M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn and Cd, and the anions are ClO4- and BF4-. The adducts have the general formula M[(C6H5)2P(O)N(CH3)2]2Cl2, where M stands for the same series of metals.The compounds are characterized and identified by chemical analyses and physical measurements.Ligand-field and vibrational spectra have been investigated; values for the ligand-field parameters are reported. It is concluded that coordination takes place via the oxygen atom of the ligand.X-ray powder patterns were used in combination with ligand-field spectra to deduce the coordination around the metal ions.The interesting behaviour of the nickel (II) chloride adduct upon heating is discussed and it is shown that both a square pyramidal and a tetrahedral modification exists.

Basic halides and related species of molybdenum(III). II. Spectroscopic and magnetic properties of MoOF(H2O)3 and MoOCl(H2O)3

1976 ◽  
Vol 29 (4) ◽  
pp. 717 ◽  
Author(s):  
DJ Stabb
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Absorption Spectroscopy ◽  
Infrared Spectra ◽  
Electronic Spectra ◽  
Related Species ◽  
Bound Water ◽  
Temperature Range ◽  
Field Dependent

Two basic halides of molybdenum(111), namely MoOF(H2O)3 and MoOCl(H2O)3 (some samples containing additional loosely bound water), were investigated by absorption spectroscopy in the range 200-50000 cm-1, and by magnetic susceptibility measurements over a temperature range of 100-300 K. Infrared spectra showed bands at about 670 and 1600 cm-l, but not in the range 800-1100 cm-1. Electronic spectra showed poorly defined bands superimposed on strong general absorption. Very weak paramagnetism was observed: this was field dependent. The results are interpreted to show the compounds to be oxygen-bridged polymers [MOX(H2O)3O]n, rather than species containing Mo=O or Mo-0-H groups.

ChemInform Abstract: SINGLE CRYSTAL ELECTRONIC SPECTRA AND LIGAND FIELD PARAMETERS OF SOME NICKEL(II) AMINE-ISOTHIOCYANATO AND AMINE-NITRITO COMPLEXES

1976 ◽  
Vol 7 (12) ◽  
pp. no-no
Author(s):  
IVANO BERTINI ◽  
DANTE GATTESCHI ◽  
ANDREA SCOZZAFAVA
Keyword(s):  
Single Crystal ◽  
Electronic Spectra ◽  
Ligand Field ◽  
Ligand Field Parameters

Ligand-Field Calculations on Pseudo-Tetragonal High-Spin Fe(II) Compounds

1977 ◽  
Vol 32 (12) ◽  
pp. 1404-1418
Author(s):  
A. Vermaas ◽  
W. L. Groeneveld ◽  
J. Reedijk
Keyword(s):  
Experimental Data ◽  
Magnetic Susceptibility ◽  
Room Temperature ◽  
Point Group ◽  
Point Symmetry ◽  
Ligand Field ◽  
Ligand Field Theory ◽  
State Splitting ◽  
Ligand Field Spectra ◽  
Theoretical Results

Abstract The compounds Fe(pz)4X2 and Fe(mpz)4X2, where pz stands for pyrazole, mpz for 5-methyl-pyrazole and X means Cl, Br or I, have been investigated by magnetic susceptibility, magnetic saturation and Mössbauer spectroscopy. The experimental temperatures vary from 2K to room temperature for the magnetic susceptibility measurements and from 4K to room temperature for the Mössbauer measurements. Mössbauer spectra in an applied magnetic field are also reported. The results of both types of measurements and ligand-field spectra are interpreted using a ligand-field theory. The tetragonal ground-state splitting parameters have been determined using the ligand-field spectra. For the pyrazole compounds, the experimental data nicely agree with theoretical results. The quadrupole splitting and the magnetic properties of these com­ pounds can be completely described within the used model, assuming a tetragonal molecular point symmetry. For the 5-methylpyrazole compounds, the measurements show that the point symmetry is lower than tetragonal. The agreement between the experimental data and the theoretical results for a point group Ci is less fair, especially concerning the Vzz and η values. Besides the Vzz values of Fe(mpz)4X2 differ significantly from those of the corresponding Fe(pz)4X2 compounds.

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