The electronic spectra and magnetic behaviour of some dithiocacodylate complexes

1971 ◽  
Vol 24 (8) ◽  
pp. 1587 ◽  
Author(s):  
AT Casey ◽  
DJ Mackey ◽  
RL Martin
Keyword(s):  
Field Strength ◽  
Electronic Spectrum ◽  
Electronic Spectra ◽  
Magnetic Behaviour ◽  
The Other ◽  
Ligand Field ◽  
Ionic Character ◽  
Nephelauxetic Effect ◽  
Other Hand ◽  
Square Planar

The large nephelauxetic effect and low ligand field strength produced by the dithiocacodylate group [(CH3)2AsS2-] in complexes with Ni2+, Co2+, and Cr3+ is explained in terms of significant covalency of the metal- sulphur bonds. The Mn2+ compound, however, has properties consistent with considerable ionic character. ��� The electronic spectrum and magnetic behaviour of bisdithiocacodylato-cobalt(II) can be better interpreted in terms of tetrahedral rather than octahedral CoSx microsymmetry. On the other hand, the Ni2+ compound is square-planar and both the Mn2+ and Cr3+ compounds appear to be octahedrally coordinated by sulphur atoms.

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.

scholarly journals Determination of the Ratios of Ligands to Metal Ion of some Metal Complexes of Triazoles by Using Eleetronie Speetra in Organie Solvents

2004 ◽  
Vol 1 (1) ◽  
pp. 110-115
Author(s):  
Baghdad Science Journal
Keyword(s):  
Solid State ◽  
Metal Complexes ◽  
Electronic Spectra ◽  
Metal Ion ◽  
The Other ◽  
Molar Ratio ◽  
Other Hand

We found that 4,5- diphenyl- 3(2- propynyl) thio- 1??-triazole [1? forms a complex with Pd (11) ion of ratio 1:1 which absorbs light in CH2CI2 at 400 nm, and 4,5- diphenyl- 3(2- propenyl) thio- 1,2,4- triazole [II] forms complexes with Pd (II) ion of ratio 1:1 which absorbs light at 390 nm, and of ratio 2:1 which absorbs light at 435 nm. On the other hand, we found that the new derivative 4- phenyl- 5( p- amino phenyl) -3- mercapto- 1,2,4- triazole ?111? forms complexes with Cu (II) ion of the ratio 1:1 which absorbs light at 380 nm, with Ni (II) ion of the ratio 3:1 which absorbs light at 358 nm; and with Co (11) ion of the ratio 3.2:1 which absorbs light at 588 nm. The ratio of the complexes were determined by measuring the electronic spectra of the complexes in CH2G2 and (CH^NCHO at different concentrations ofthe ligands and f?xed ' •' of the metal ion in every case, then applying the molar ratio plots on the data. Our results were confirmed by precipitating most ofthe above complexes in solid state, and then each complex was analyzed elementally.

Sulphur-nitrogen chelating agents. VIII. Magnetic behaviour of some cobalt(II) complexes at the crossover region

1969 ◽  
Vol 22 (9) ◽  
pp. 1825 ◽  
Author(s):  
PSK Chia ◽  
SE Livingstone
Keyword(s):  
Field Strength ◽  
Thermal Equilibrium ◽  
Chelating Agents ◽  
Magnetic Behaviour ◽  
Ligand Field ◽  
Crossover Region ◽  
Methyl Group ◽  
Quantitative Treatment

The bis-ligand cobalt(II) complexes of 6-methylpyrid-2-yi-N-(2?- methylthio-phenyl)methyleneimine (SNNMe) are spin-free and the corresponding complexes of 2-pyridyl-N-(2?- methylthiophenyl)methyleneimine (SNN) are spin-paired. This difference in magnetic behaviour arises from a lower effective ligand field strength of SNNMe, presumably due to the steric inter-ligand interference introduced by the methyl group in the 6-position of SNNMe. The moments of the cobalt(II) complexes are dependent on temperature and the departures from the Curie-Weiss law are quite anomalous. No quantitative treatment is given for the anomalous magnetic behaviour; however, the results are best explained as a thermal equilibrium between the nearly equi-energetic spin-paired and spin-free states of the cobalt(II) atom.

Single-crystal polarized electronic spectra, ligand field analysis, and vibronic analysis of olefin complexes of square-planar platinum(II)

1987 ◽  
Vol 26 (25) ◽  
pp. 4204-4208 ◽  
Author(s):  
Huey Rong C. Jaw ◽  
Tsu Hsin Chang ◽  
Jeffrey I. Zink
Keyword(s):  
Single Crystal ◽  
Electronic Spectra ◽  
Field Analysis ◽  
Ligand Field ◽  
Square Planar ◽  
Vibronic Analysis

Thio derivatives of β-diketones and their metal chelates. X. The anomalous paramagnetism of some iron(III) chelates of monothio-β-diketones

1968 ◽  
Vol 21 (8) ◽  
pp. 1987 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone
Keyword(s):  
Iron Atom ◽  
Thermal Equilibrium ◽  
Room Temperature ◽  
Magnetic Behaviour ◽  
The Other ◽  
Ligand Field ◽  
Pairing Energy ◽  
Temperature Dependent ◽  
Magnetic Susceptibilities ◽  
Derivatives Of

The magnetic susceptibilities of the iron(111) chelates Fe(R1CS=CHCOR2)3 (R1 = Ph, p-MeC6H4, p-MeOC6H4, p-BrC6H4, 2-thienyl, 2-furyl, R2 = CF3; R1 = Ph, R2 = Ph, OEt) have been investigated over a temperature range. The iron(111) complex of ethyl thiobenzoylacetate (R1 = Ph, R2 = OEt) is of the high-spin type and obeys the Curie-Weiss law with θ =-8�k. The moments of the other complexes vary between 2.31 and 6.61 B.M. at room temperature and are temperature-dependent, ranging from 1.86 to 4.07 B.M. at 80�k, depending on the nature of R1 and R2 This behaviour is postulated to be due to a thermal equilibrium between the nearly equi-energetic spin-paired (t5/2g) and spin-free (t3/2ge2/g) configurations of the iron atom, resulting from the approximately equal magnitudes of the ligand field (Δ) and the pairing energy (π) in these complexes. The ligand field and consequently the magnetic behaviour are sensitive to the nature of R1 and R2: electron-withdrawing groups appear to be the most effective in increasing the population of the spin-paired configuration.

Iron(II) and Nickel(II) Complexes of 6-(Pyrazol-1-yl)-2,2' -bipyridine

1999 ◽  
Vol 52 (4) ◽  
pp. 339 ◽  
Author(s):  
Anthony T. Baker ◽  
Jeremy P. Matthews
Keyword(s):  
Magnetic Susceptibility ◽  
Field Strength ◽  
Electronic Spectra ◽  
Strong Field ◽  
Electronic Spectroscopy ◽  
Magnetic Behaviour

Iron(II) and nickel(II) complexes of 6-(pyrazol-1-yl)-2,2′-bipyridine (pzbpy) have been prepared and characterized by magnetic susceptibility measurements and electronic spectroscopy. The magnetic behaviour of the iron(II) complexes and the electronic spectra of the nickel(II) complex indicate that pzbpy is a relatively strong-field ligand though its field strength is not as high as that of 2,2′:6′,2″-terpyridine. Comparisons of the field strength of terimine and analogous ligands are presented.

Octabutanol(dodecaoxidododecaphenyl[18.4.0]dodecasiloxane)tetracopper(II)tetrasodium(I)

2006 ◽  
Vol 62 (4) ◽  
pp. m705-m707 ◽  
Author(s):  
Christian Bauch ◽  
Larissa Zherlitsyna ◽  
Norbert Auner ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Coordination Mode ◽  
Molecular Conformation ◽  
The Other ◽  
Site Symmetry ◽  
Other Hand ◽  
Square Planar

Molecules of the title compound, [Cu4Na4(C6H5O2Si)12(C4H10O)8], are located on special positions of site symmetry \overline{4}. The Cu atoms are coordinated in a square planar fashion. The Na atoms, on the other hand, show an irregular sixfold coordination mode. The molecular conformation is stabilized by O—H...O hydrogen bonds.

Tetra-μ2-cyano-κ8 C:N-μ2-2,6-dimethylpyrazine-κ2 N:N′-hexakis(2,6-dimethylpyrazine-κN)octa-μ2-thiocyanato-κ16 N:S-decacopper(I,II)

2006 ◽  
Vol 62 (4) ◽  
pp. m721-m723 ◽  
Author(s):  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Formula Unit ◽  
Asymmetric Unit ◽  
Special Position ◽  
Coordination Network ◽  
Other Hand ◽  
Square Planar

The asymmetric unit of the title compound [Cu8 ICu2 II(CN)4(NCS)8(C6H8N2)7], consists of six crystallographically independent Cu atoms, four thiocyanate anions and two cyanide anions, as well as four 2,6-dimethylpyrazine ligands. Two of the six Cu atoms and one of the four 2,6-dimethylpyrazine ligands are located on centres of inversion. The ligand on a special position is therefore disordered due to symmetry. Altogether there are two copper(II) and eight copper(I) cations in the formula unit. The copper(II) cations are each coordinated by four N atoms within a slightly distorted square-planar coordination. The copper(I) cations, on the other hand, are coordinated by four ligands or anions within distorted tetrahedra. From this arrangement, a three-dimensional coordination network is formed.

Preparation, Infrared Spectra, Electronic Spectra, and Magnetic Moments of Copper(II) Complexes of N-Acetylglycine and Their Amine Adducts

1974 ◽  
Vol 52 (21) ◽  
pp. 3607-3611 ◽  
Author(s):  
G. Marcotrigiano ◽  
G. C. Pellacani
Keyword(s):  
Infrared Spectrum ◽  
Infrared Spectra ◽  
Elemental Analysis ◽  
Magnetic Moment ◽  
Electronic Spectra ◽  
Magnetic Moments ◽  
The Other ◽  
Square Planar ◽  
Amine Adducts ◽  
Planar Pattern

Compounds of the type [CuA2•H2O]2 and [CuA2•4H2O]2 have been prepared, where A is N-acetylglycine (aceturic acid). Amine adducts of the type CuA2B (B = piperazine, 2,2′-bipyridine, and 1,10-phenantroline) and CuA2B2 (B = N-methylpiperazine, piperidine, morpholine, pyridine, and ethylenediamine) were obtained by reaction of the amines with CuA2•4H2O. Each complex was characterized by elemental analysis, infrared spectrum, electronic spectrum, and magnetic moment. For the piperazine and ethylenediamine adducts a square-planar pattern of coordination about copper(II) ion is probable, while for the other amine adducts a square-pyramidal structure is proposed. For all the complexes the coordination of the N-acetylglycine occurs only through the terminal carboxyl oxygen in a monodentate arrangement.

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