Iron complexes thiocyanato

Fluoride can be determined by means of an iron(iii) thiocyanato complex extracted into isobutylketone. Iron is extracted back into the aqueous phase with the fluoride sample solution. The atomic absorption signal of iron is directly proportional to the concentration of fluoride (0.5-6 ju,g F ml ). EDTA can be determined by a similar technique. Copper is first extracted as the hydroxyquinolinato complex into isobutylketone, and then extracted back into the aqueous solution with the EDTA sample solution. In these methods the analyte anion must form a more stable complex compound with the metal ion than the ligand used for the first solvent extraction. These kind of... 

The most important publications dealing with multicomponent systems were those of Jannik BJerrum on copper(II)-ammine complexes (15-17) and of Holler on iron(III)- thiocyanato complexes (18). 

The participation of a monomer molecule in the initiation step of polymerization has not been required in the examples described so far. Tris(thiocyanato) tris(pyri-dine) iron(III) complex forms a complex with methyl methacrylate [46]. By subjecting the compound to UV radiation, the complex decomposes to give SCN as the initiating radical. 

Besides complexes of thiosemicarbazones prepared from nitrogen heterocycles, iron(III) complexes of both 2-formylthiophene thiosemicarbazone, 26, and 2-acetylthiophene thiosemicarbazone, 27, have been isolated [155]. Low spin, distorted octahedral complexes of stoichiometry [Fe(26)2A2]A (A = Cl, Br, SCN) were found to be 1 1 electrolytes in nitromethane. Low spin Fe(27)3A3 (A = Cl, Br, SCN) complexes were also isolated, but their insolubility in organic solvents did not allow molar conductivity measurements. Infrared speetra indicate coordination of both via the azomethine nitrogen and thione sulfur, but not the thiophene sulfur. The thiocyanate complexes have spectral bands at 2065, 770 and 470 cm consistent with N-bonded thiocyanato ligands, but v(FeCl) and v(FeBr) were not assigned due to the large number of bands found in the spectra of the two ligands. 

Another interesting point is the relative rates of the reactions of the azido and thiocyanatopentaammines. The relative rates of these two reactants with iron (I I) ion are similar to those with chromium (I I), that is, the azide is four to five powers of ten more rapid than is the thiocyanato. I am suggesting that this might be a criterion for inner sphere activated complex as opposed to an outer sphere complex. With trisdipyridylchromium(II) ion, which must react via an outer sphere process, the azido and thiocyanato rates are relatively comparable, and the same also for vanadium (I I) ion which also probably procedes via an outer sphere activated complex. 

Complexes. N-Donor ligands. I.r. data have been reported for thiocyanato-iron(m) complexes, both in the solid state and in solution. There is some evidence that the octahedral anion [Fe(CN)f>]3 changes configuration to a tetrahedral species in low-polarity solvents.262... 

Thiocyanate is used in some cases for the detection of ions. Its reaction with iron(III) ion is characteristic and can be used for detecting both ions. The deep-red colour observed is due to the formation of a number of thiocyanato-ferrate(III) ions and also of the chargeless molecule [Fe(SCN)3], The blue tetrathiocyanatocobaltate(II) [Co(SCN)4]2 complex is sometimes used for the detection of cobalt. 

POLSf-BIS(THIOC YANATO-AT)BIS-(i-(lW-l, 2,4-TRIAZOLE-AP,AT4)METAL(II) COMPLEXES WITH MANGANESE, IRON, COBALT, NICKEL, COPPER AND ZINC, AND BIS[TRIS(THIOCYANATO- V)TRIS( x-4//-l,2,4-TRIAZOLE-ATI)NICKEL(II)-A2 V2VVrlNICKEL(H)... 

Iron. The rate law for the reaction of the S-bonded thiocyanato-complex [Fe(CN)5(SCN)] with hydroxide ion suggests two parallel paths. The first is a D or 5 Nl(lim) path, with an [Fe(CN)6] intermediate discriminating between hydroxide ion and thiocyanate ion. The second path is thought to involve the intermediacy either of [Fe(CN)5(OH)(SCN)] or of [Fe(CN)6(NCS)] . An S Nlcb process is, of course, precluded here. The reactions of optically... 

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