Diolefincobalt(0)-Komplexe / Diolefincobalt(0) Complexes

Mononuclear cobalt(0) complexes containing diolefin and trimethylphosphane ligands Co(cycloocta-1,5-diene)(PMe3)2 and Co[(CH2=CHMe2Si)2O](PMe3)2 are obtained from CoCl2 by reaction with magnesium in the presence of the ligands or by substitution of cobalt(olefin)tris- (trimethylphosphane) with diolefin. Chemical and spectroscopic properties confirm the para- magnetic valence state of the compounds in solution. An X-Ray crystal structure determination of Co[(CH2=CHMe2Si)2O](PMe3)2 shows a tetrahedral arrangement of ligand functions around the cobalt atom. With butadiene a diamagnetic dinuclear complex [Co(C4H6)(PMe3)3]2 is obtained containing π-allyl co-ordination of two Co(PMe3)3 units to a linear dimer of butadiene

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Monoolefincobalt(0)-Komplexe / Monoolefincobalt(0) Complexes

Zeitschrift für Naturforschung B ◽

10.1515/znb-1988-1008 ◽

1988 ◽

Vol 43 (10) ◽

pp. 1256-1262 ◽

Cited By ~ 7

Author(s):

Hans-Friedrich Klein ◽

Goetz Lull ◽

Birgit Rodenhäuser ◽

Gerhard Cordier ◽

Helmut Paulus

Keyword(s):

Crystal Structure ◽

Carbon Monoxide ◽

Valence State ◽

Cobalt Atom ◽

Spectroscopic Properties ◽

X Ray ◽

Mononuclear Cobalt ◽

Structure Determinations

Mononuclear cobalt(o) complexes containing olefin and trimethylphosphane ligands Co(olefin)(PMe3)3 (olefin = C2H4 (1), C3H6 (2), cyclopentene (3), trans-1,2-diphenylethene (4), tetrafluorobenzo-bicyclo-(2.2.2)-octadiene (5)), are obtained from CoCl2 by reaction with magnesium in the presence of the ligands or by substitution of 3 with olefin. X-ray crystal structure determinations of 4 and 5 show a distorted tetrahedral arrangement of ligands around the cobalt atom. Chemical and spectroscopic properties are consistent with a paramagnetic valence state of the compounds in solution. By reaction with carbon monoxide a dicobalt complex is formed, while azobenzene gives paramagnetic Co(N2Ph2)(PMe3)2.

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The first X-ray crystal structure determination of a dinuclear complex trapped in the [low spin–high spin] state: [FeII2(PMAT)2](BF4)4·DMF

Chemical Communications ◽

10.1039/b415891a ◽

2005 ◽

pp. 987-989 ◽

Cited By ~ 110

Author(s):

Marco H. Klingele ◽

Boujemaa Moubaraki ◽

John D. Cashion ◽

Keith S. Murray ◽

Sally Brooker

Keyword(s):

Crystal Structure ◽

High Spin ◽

Spin State ◽

Structure Determination ◽

High Spin State ◽

Dinuclear Complex ◽

Crystal Structure Determination ◽

X Ray

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The protonation of the ethylenediphosphinetetraacetate anion and the crystal structure of the bis (hydrogen bromide) of ethylenediphosphinetetraacetic acid

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19813063 ◽

1981 ◽

Vol 46 (12) ◽

pp. 3063-3073 ◽

Cited By ~ 5

Author(s):

Jana Podlahová ◽

Bohumil Kratochvíl ◽

Vratislav Langer ◽

Josef Šilha ◽

Jaroslav Podlaha

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Structure Determination ◽

Free Acid ◽

Hydrogen Bromide ◽

Carboxyl Groups ◽

Spectroscopic Methods ◽

X Ray ◽

Partial Formation

The equilibria and mechanism of addition of protons to the ethylenediphosphinetetraacetate anion (L4-) were studied in solution by the UV, IR, 1H and 31P NMR spectroscopic methods. A total of six protons can be bonded to the anion. They are added stepwise, first with partial formation of zwitterions containing P-H bonds, which then dissociate with formation of the free acid, H4L, where all four protons are bonded in carboxyl groups. The formation of zwitterions is strongly dependent on the concentration. In the final stage, the acid bonds two additional protons to form the bis-phosphonium cation, H6L2+. A number of isostructural salts containing this cation, H4L.2 HX (X = Cl, Br, I), have been prepared. The X-ray crystal structure determination of the bromide confirmed the expected arrangement. The bromide crystals are monoclinic, a = 578.2, b = 1 425.0, c = 1 046.7 pm, β = 103.07° with a space group of P21/c, Z = 2. The final R factor was 0.059 based on 1 109 observed reflections. The structure consists of H6L2+ cations containing protons bonded to phosphorus atoms (P-H distance 134 pm) and of bromide anions, located in gaps which are also sufficiently large for I- anions in the isostructural iodide. The interbonding of phosphonium cations proceeds through hydrogen bonds, C-OH...O=C, in which the O...O distance is 275.3 pm.

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