Cobaltate ethylenediaminetetraacetato

Busch and Bailar1 obtained optically active solutions of one of the enantiomers of the ethylenediaminetetraacetato-cobaltate(III) ion by selective adsorption on optically active quartz and by fractional crystallization of the strychnine salt. More recently Dwyer, Gyarfas, and Mellor2 reported the complete resolution using d and Z-tris(ethylenediamine) cobalt(III) chloride. Precipitation of the diastereoisomers was effected by addition of ethanol to the aqueous solution. The volume of ethanol used was critical and often merely the potassium salt separated. 

R2-R5- The fourth pair, R2-R4, is not used because the two rings are coplanar. The method described above gives A for R1-R4, A for R1-R5, and A forR2-R5. The notation for the compound given is then AA A-(ethylenediaminetetraacetato)cobaltate(III). The order of the designations is arbitrary, and could as well be AAA or A A A. 

Co(CioHi2N2Os)H2 Cobalt ethyl-enediaminetetraacetate, 5 187ra. [Co(CioHi2N2Os)]K Potassium (ethylenediaminetetraacetato)-cobaltate(III), 5 186 [Co(CioHi2N208)]Na Sodium... 

Cl6H32ClaMo2NsO 2 6 H2O, Tetrakis(glycylglycine) dimolybdenum(lI) tetrachloride hexahydrate, 46B, 1038 C16H32C02N6O13, (+)-cis(0) Triammine(sarcosinate-N propionato)co-balt(III) ( + )-(ethylenediaminetetraacetato)cobaltate(III) monohydrate, 44B, 902... 

Cl H24CO2N2O14, Tetraaquocobalt(II) (ethylenediaminetetraacetato(4-))cobaltate(II) dihydrate, 44B, 1008 Cl Hj4N2O14Zn2, Zinc ethylenediaminetetraacetate hexahydrate, 39B, 789... 

Write a structural formula for (ethylenediaminetetraacetato)cobaltate(III). Is this anion chiral Briefly support your answer. 

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