Correlation of vibrational and electronic spectra. 1. Vibronic intensity distributions and ligand-field strengths in d-d spectra of five planar CuCl2X2 chromophores

1994 ◽  
Vol 33 (24) ◽  
pp. 5411-5423 ◽  
Author(s):  
Adam J. Bridgeman ◽  
Sarah J. Essex ◽  
Malcolm Gerloch
Keyword(s):  
Electronic Spectra ◽  
Ligand Field ◽  
Field Strengths

Magnetism, electronic spectra, and structure of transition metal alkoxides. I. methoxides and ethoxides of chromium(II), manganese(II), Iron(II), cobalt(II), nickel(II), copper(II), titanium(III), chromium(III), and iron(III)

1966 ◽  
Vol 19 (2) ◽  
pp. 207 ◽  
Author(s):  
RW Adams ◽  
E Bishop ◽  
RL Martin ◽  
G Winter
Keyword(s):  
Transition Metal ◽  
Spectral Data ◽  
Electronic Spectra ◽  
Magnetic Moments ◽  
Field Parameter ◽  
Ligand Field ◽  
Metal Alkoxides ◽  
Infinite Lattices ◽  
Ligand Field Parameter

The magnetic moments and electronic spectra are reported for the following divalent transition metal methoxides: Cr(OCH3)2, Mn(OCH3)2, Fe(OCH3)2, Co(OCH3)2, Ni(OCH3)2, and Cu(OCH3)2. These measurements when coupled with the involatility and insolubility of the compounds favour structures based on infinite lattices composed either of regular (Mn, Fe, Co, and Ni) or distorted (Cr and Cu) MO6 octahedra. The spectral data place the ligand field parameter, Δ, for the methoxide group very close to that of water.

Ligand field strengths and oxidation states from manganese L-edge spectroscopy

1991 ◽  
Vol 113 (21) ◽  
pp. 7937-7940 ◽  
Author(s):  
S. P. Cramer ◽  
F. M. F. DeGroot ◽  
Y. Ma ◽  
C. T. Chen ◽  
F. Sette ◽  
...  
Keyword(s):  
Oxidation States ◽  
Ligand Field ◽  
Field Strengths

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.

Single crystal electronic spectra of a series of trans nickel(II) complexes with N,N′-diethyl- and N,N′-dimethylethylenediamine

1977 ◽  
Vol 55 (17) ◽  
pp. 3172-3189 ◽  
Author(s):  
A. B. P. Lever ◽  
G. London ◽  
P. J. McCarthy
Keyword(s):  
Steric Hindrance ◽  
Electronic Spectra ◽  
Spherical Harmonic ◽  
Bonding Strength ◽  
Ligand Field ◽  
Transition Energies ◽  
B Values ◽  
Axial Ligands ◽  
Symmetry Adapted Functions ◽  
Spectrochemical Series

We have measured the polarized crystal spectra at 10 K. of Ni(s-Et2en)2X2, where X = Cl, Br, NCS, and H2O (with Cl, Br, and I counterions) and *-Et2en is N, N'-diethylethylenediamine, and of Ni(s-Me2en)2X2, where X = NCS and NO3, and.s-Me2en is N,N′-dimethylethylenediamine. Transition energies were calculated for D4h symmetry using symmetry adapted functions and a normalized spherical harmonic Hamiltonian. When the differences between calculated and observed band positions are minimized, the ligand-field and angular overlap parameters listed in Table 2 are obtained. The criteria for the band assignments are discussed. The principal conclusions are: (1) The π interactions between Ni(II) and the axial ligands are small in contrast to tetragonal Cr(III) complexes. (2) Equatorial and axial parameters are relatively independent, in contrast to tetragonal Cu(II) complexes. (3) The more basic,s-Et2en exerts a stronger ligand field than,s-Me2en. (4) The σ-bonding strength of the axial ligands follows the spectrochemical series. (5) DQ for the axial ligands in the ethyl complexes is lower than anticipated, probably due to steric hindrance of the bulky ethyl groups. (6) B values are all near 850 cm−1, except for an anomalously low value for Ni(s-Et2en)2(NCS)2.

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.

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