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

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.

1974 ◽  
Vol 29 (7-8) ◽  
pp. 527-531 ◽  
Author(s):  
J. C. Jansen ◽  
J. Reedijk

Coordination compounds of formula Ni(Iz)nX2(H2O)m, in which Iz=imidazole, n = 1, 2, 4, 6, m = 0-4, and X = Cl-, Br-, I- and NCS-, are described. The anhydrous compounds are prepared from ethanolic solutions of Iz and nickel(II) salts in stoichiometric amounts in the presence of the dehydrating agent triethylorthoformate. Without this dehydrating agent hydrates are isolated for n = 2,4 and 6 with X = Cl, Br.The compounds were identified by means of infrared spectra (4000-25 cm-1), ligand-field spectra (35000-4000 cm-1) and X-ray powder diagrams. Compounds of formula [Ni(Iz)6]X2 all contain octahedrally coordinated Ni2+, for which the spectrochemical parameters were obtained. Tetragonal Ni2+ ions occur in [Ni(Iz)4X2] in which X = Cl and NCS, and in [Ni(Iz)4(H2O)2]X2 in which X = Cl and Br. These compounds are paramagnetic and the crystal-field parameters for tetragonal symmetry have been calculated. In [Ni(Iz)4]X2 with X = I and Br, the Ni2+ ions are square-planar coordinated with anions in the second coordination sphere, resulting in orange-coloured diamagnetic compounds.Anion-bridged distorted octahedrally coordinated Ni2+ ions probably occur in the compounds of formula Ni(Iz)2X2, in which Iz takes the axial positions. Similar structures are suggested for the mono-imidazole compounds, NiIzX2.


1969 ◽  
Vol 24 (10) ◽  
pp. 1518-1525
Author(s):  
C. Friebel ◽  
D. Reinen

Abstract The ESR-powder-spectra of the perovskite-mixed-crystals M2II (CuxZn1-xW)O6 [MII=Sr, Ba] and Sr2(CuxZn1-xTe)O6 , which have been investigated by means of conventional X-ray-techniques and ligand-field-spectroscopy 1,2, are described and the results extensively discussed. The conclusions can be summarized as follows: (a) At very low x-values isolated, dynamically Jahn-Teller-distorted CuO6-octahedra are present in the cubic matrices, which can be frozen into tetragonally elongated polyhedra at 4.2 °K; (b) At high x-values the CuO6-entities are statically JT-distorted with the long axes lined up along the c-axis of the macroscopically tetragonal phases; (c) The ESR-spectra around the cubic-tetragonal phase-transition are complex, containing signals of obviously magnetically coupled Cu2+-ions; (d) The g-values "follow" the ligand-field-parameters quantitatively. Comparative data of some other compounds are given.


1982 ◽  
Vol 60 (4) ◽  
pp. 514-520 ◽  
Author(s):  
Laurence Kenneth Thompson ◽  
John Charles Thomas Rendell ◽  
George Charles Wellon

The nickel coordination chemistry of two potentially bidentate bis-benzothiazole ligands is compared. 1,2-Bis(2-benzothiazolyl)-benzene (OBT), which has an o-phenylene bridge, forms square planar derivatives with NiX2 (X = I, ClO4, BF4), octahedral derivatives with NiX2 (X = NCS, NO3), and five-coordinate derivatives with NiX2 (X = CI, Br). 1,2-Bis(2-benzothiazolyl)ethane (BBTE), which has an ethylene bridge, forms tetrahedral derivatives with NiX2 (X = CI, Br, I) and an octahedral complex with Ni(NO3)2. Although both ligands are capable of tetrahedral coordination about a cobalt centre, the apparent preference of tetrahedral coordination with nickel complexes of BBTE seems unusual. The only difference between the two ligands lies in the bridging group between the benzothiazole rings. Structural assignments are supported by ligand field and infrared spectra, magnetic data, and an X-ray structure of the complex [Ni(BBTE)Br2], which has been shown to have a distorted tetrahedral stereochemistry.


1974 ◽  
Vol 29 (5-6) ◽  
pp. 295-303 ◽  
Author(s):  
Claus Friebel

Structural relations between perovskite-related lattices of the type A2CuL6 and the perovskite compounds A2(12) [BCu](6)L6 (1: 1 order in the octahedral sites, elpasolite type) are demonstrated by two examples, the compounds A,Cu(OH)6 [A = Ba, Sr] and Ba2CuF6. From the ESR spectra a coupling of Jahn-Teller-distorted Cu-ligand-octahedra in these compounds corresponding to a “disturbed” type of antiferrodistortive order can be deduced. This result is in agreement with recent X-ray structure determinations. The ligand field spectra of the hydroxocuprates(II) indicate tetragonally elongated CuO6-octahedra with very long axial distances. From the ESR investigations further conclusions can be drawn concerning structural differences between the Ba- and the Sr-compound [Sr2Cu(OH6)], the atomic parameters of which are still unknown.


1993 ◽  
Vol 46 (11) ◽  
pp. 1799 ◽  
Author(s):  
TM Donlevy ◽  
LR Gahan ◽  
TW Hambley ◽  
KL Mcmahon ◽  
R Stranger

A revised synthesis of the hexadentate ligand 5-(4-amino-2-thiabutyl)-5-methyl-3,7-dithianon- ane-1,9-diamine (N3S3) is reported. Reaction between the sodium salt of 2-aminoethanethiol and 1,1,1-tris([( tolylsulfonyl )oxy]methyl)ethane in refluxing ethanol results in the formation of the hexadentate ligand N3S3. The preparation of the nickel(II) and cobalt(III) complexes is reported. The crystal structure of [Co(N3S3)](ClO4)3.H2O has been determined by X-ray diffraction methods and refined to a residual of 0.044 for 3696 independent observed reflections. The crystals are monoclinic, P21/n, a 9.314(4), b 15.581(6), c 17.026(3) Ǻ, β 90.30(4)°. Low temperature (c.10 K) absorption spectra are reported for [Co(N3S3)]3+ and the analogous encapsulated complex [Co(AMN3S3sarH)]4+ where both the spin-allowed 1A1g → 1T1g, 1T2g and spin-forbidden 1A1g → 3T1g, 3T2g were observed. Ligand -field calculations based on octahedral symmetry result in the ligand -field parameters B 461, C 3075, Dq 2303 cm-1, and B 462, C 3085, Dq 2266 cm-1 for the [Co(N3S3)]3+ and [Co(AMN3S3sarH)]4+ complexes, respectively. A systematic reduction occurs in the Racah B parameter of between 25 and 30 cm-1 for each additional thioether donor in the series of complexes N6-xSx (x = 0, 1, 2, 3). In addition, there is evidence for a progressive increase in the Racah C/B ratio with increasing number of thioether donors in this series.


1969 ◽  
Vol 47 (12) ◽  
pp. 2275-2282 ◽  
Author(s):  
Pakinam Askalani ◽  
R. A. Bailey

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.


1981 ◽  
Vol 36 (7) ◽  
pp. 802-808 ◽  
Author(s):  
Ger Vos ◽  
Jaap G. Haasnoot ◽  
Willem L. Groeneveld

Abstract Coordination compounds of 4-ethyl-1,2,4-triazole (Ettrz) with Mn, Fe, Co, Ni, Cu and Zn are reported. The compounds have been identified and characterized by chemical analyses, infrared and ligand field spectra, electron paramagnetic resonance (e.p.r.) measurements, magnetic susceptibility measurements and thermoanalytical experiments. Except for the Cu compound, which is polynuclear, all compounds appear to be binuclear, with both bridging bidentate and non-bridging triazole ligands. The overall formula is M(Ettrz)2(NCS)2(H2O)3/2 for Mn, Fe, Co and Ni. The copper and zinc compounds have the formula Cu(Ettrz)2(NCS)2 and Zn(Ettrz)3/2(NCS)2.


1976 ◽  
Vol 31 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R. Haegele ◽  
D. Babel ◽  
D. Reinen

While the stable modification of CsNiF3 is of green colour, a yellow phase is obtained by fluorination of CsNiCl3 and decomposition of the product “CsNiF4”, which contains Ni4+ and Ni3+ besides Ni2+. The two modifications have the 2L- and 9L-perovskite-structure, respectively, and are characterized by their X-ray patterns and low-temperature ligand field spectra. The differences in colours and spectral band positions are discussed with respect to the Ni-F-Ni bond angles


1974 ◽  
Vol 27 (3) ◽  
pp. 509 ◽  
Author(s):  
PP Singh ◽  
AK Srivastava

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.


2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.


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