Oxalato salts, tri

Oxalates, determination of, in rare earth oxalates, 2 60 Oxalato salts, tri-, 1 35 Oxides, reduction of refractory metal, to metal powders with calcium, 6 47... 

There is a wide range of diketonates, such as Ru(acac)3, with octahedral coordination [133b] (they do not seem, however, to be oxidized to the +4 state this is possible with osmium) similarly several salts of the tris(oxalato) complex Ru(C204)3 have been isolated. 

Chromium, tris(hexafluoroacetylacetonato) optical isomerism, 1, 28 Chromium, tris(oxalato)-raceinization solid state, 1,466 strychnine salt... 

The salt K3[Cr(C204)] 3H20 is soluble in water. The crystals are dichroic, being green-blue by transmitted light and magenta by reflection. The infrared spectra of this and other tris(oxalato) complexes have been recorded and analyzed.17... 

After the resolution of 1-2-chloro-ammino-diethylenediamino-cobaltie chloride many analogous resolutions of optically active compounds of octahedral symmetry were carried out, and active isomers of substances containing central cobalt, chromium, platinum, rhodium, iron atoms are known. The asymmetry is not confined to ammines alone, but is found in salts of complex type for example, potassium tri-oxalato-chromium, [Cr(Ca04)3]K3, exists in two optically active forms. These forms were separated by Werner2 by means of the base strychnine. More than forty series of compounds possessing octahedral symmetry have been proved to exist in optically active forms, so that the spatial configuration for co-ordination number six is firmly established. 

Hexamminecobalt(III) salt cannot be used as a precipitant in the oxalato complex precipitation system because it precipitates as hexamminecobalt(III) oxalate. Besides the hexaureachro-mium(III) salt, hexamminechromium(III), tris(ethylenediamine)cobalt (III) or tris(trimethylenediamine)cobalt(III) salts can be used as precipitants. Hexamminechromium(III) and tris(ethylenediamine) cobalt (III) salts form precipitates with actinide(IV) or (VI) oxalato complex ions, whereas tris(trimethylenediamine)co-balt(III) salt forms precipitates with Th(IV) or U(VI) oxalato complex ions leaving Pu(IV) ion in the supernatant solution.Therefore, this reagent plays the role of both a separating agent and a precipitant and is applicable for the separation of Pu(IV) ion from Th(IV) or U(VI) ion. 

Although Werner considered both enantiomers of potassium tris-(oxalato)chromate(III) to be monohydrates, Charonnat and Dele-pine, on the basis of isomorphism with the corresponding iridium salt, proposed that they are dihydrates. The (+) enantiomer has been described as bluish red in the dry, pure condition. - The optical enantiomers are less soluble in water than the racemic mixture. Because of the high rate of racemization in water, recrystallization has been reported to be accompanied by a considerable loss of optical rotation. For the same reason, the optical rotation values reported by different workers are not directly comparable. ... 

Chromate, tetrakis(dioxygen)-stereochemistry, 94 Chromate, tricyanodiperoxy-structure, 78 Chromate, tris(oxalato)-racemization solid state, 466 strychnine salt racemization, 466 Chromatography optical resolution, 26 Chrome azurol S metallochromic indicator, 556 Chromium... 

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