Tris-oxalato complexes, racemization

Iron, tris(hexafluoroacetylacetone)-structure, 1,65 Iron, tris(oxalato)-chemical actinometer, 1,409 photoreduction, 1,471 relief-image-forming systems, 6,125 Iron, tris(l,10-phenanthroline)-absorptiometry, 1,549 racemization, 1,466 solid state, 1,467 structure, 1, 64 lron(III) chloride amino acid formation prebiotic systems, 6,871 Iron complexes acetonitrile. 4,1210 acetylacetone, 2,371 amidines... 

Numerous kinetic studies of racemization reactions have been performed with tris(oxalato) metal complexes, 17, M(OX)3 3 in aqueous solution where... 

Bidentate oxygen ligands form numerous rhodium(III) complexes. Several tris(jS-diketonato) complexes have been prepared from rhodium(III) nitrate (equation 35). The products are extraordinarily stable. They can be resolved into their optical isomers, and survive nitration and formylation reactions (equations 36 and 37). The tris(oxalato)rhodate(III) ion has also been resolved, but the enantiomers undergo slow racemization. Reaction of this complex with refluxing chloric(VII) acid leads to m-[Rh(ox)2(H20)2], which can be converted into cis- or frani -[RhX2(ox)2] complexes. 

The tris(oxalato)chroinate(III) ion, [Cr(Cj04)3P , possesses the double historical distinction of being both the first resolved complex anion and the first resolved complex that did not contain nitrogen. Since it racemizes rapidly in aqueous solution, more so than the corresponding cobalt(III) ion, virtually all of this labile complex can be separated as a single en-... 

It must be concluded, therefore, that the ligands do not become completely detached from the metal ion in isomerization reactions. Comparable results have been observed in the isomerization of potassium diaquodioxalatochromium(III) and the racemization of optically active potassium tris(oxalato)chromium(III) when no exchange with free ligand in solution occurs. Thus, although it is not practicable to take advantage of the desirable properties of individual isomers of 2 1 chromium and cobalt complexes of tridentate azo compounds because of the facility with which such compounds isomerize in solution, the technically important unsymmetrical 2 1 complexes are capable of practical application because they show little or no tendency to disproportionate in solution. 

Cobaltate, tris(l, 2-ethanediamine)-racemization solid state, 466 Cobaltate, tris(oxalato)-racemization solid state, 467 Cobaltates sepulchrates, 22 Cobalt complexes geometric isomerism, 11 hexaammine... 

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