Cobaltate glycinato

The kinetic effects of C02 in the base catalyzed hydrolysis of some carboxylato amine cobalt(III) complexes have been reported (80-82). In the base catalyzed hydrolysis of oxalatopentaammine-cobalt(III) (80), C02 retarded the reaction due to the formation of a virtually unreactive ion-pair, f (N H .) r, 2 2 COi ]. The equilibrium constant for formation of carbonate ion-pairs with (glycinato-O) (tetraethylene-pentamine)cobalt(III), (81) and (o-methoxybenzoato) (tetraethylenepentamine)cobalt(III) (82) were, however, much smaller than for the oxalatopentamminecobat(III) and a very weak rate retardation and virtually no effect was observed in the base catalyzed hydrolysis of the latter two complexes. 

Not only can the a-methylene carbanion be produced and stabilized, but it can also undergo base-catalyzed aldol-type reactions without decomposition of the chelate ring. The most-studied reactions involve carbanion additions to acetaldehyde to produce threonine and allothreonine. This can be achieved for bis(glycinato)copper(II),48,49 tris(glycinato)cobalt(III)50,51 or glycinato-bis(l,2-diaminoethane)cobalt(III),52 with the best yield being obtained in the last case, where the... 

Glycine has the structure NH2CH2COOH. It can lose a proton from the carboxyl group and form chelate rings bonded through both the N and one of the O atoms. Draw structures for all possible isomers of tris(glycinato)cobalt(III). 

One of the earliest cases of stereoisomerism among inner complexes, tris(glycinato)cobalt(III), occurs in two forms, violet (a) and red (P). In one of these geometric isomers, all of the amino groups of the glycine molecules are adjacent (fac), while in the other, two of these occupy opposite positions mer). Absorption spectra indicate that the more soluble violet a form is the mer isomer. " ... 

According to Ley and Winkler, mer(a)-tris(glycinato)cobalt(III) forms large, dark violet, rhombic crystals containing two molecules of water of crystallization, while /flcO)-tris(glycinato)cobalt(III) forms reddish pink, needlelike crystals with one molecule of water of crystallization. Contrary to these results, our analytical and thermogravimetric data have shown the pink form to be anhydrous and the violet form to be a monohydrate. The number of molecules of water of crystallization varies with conditions of drying. 

C0CI3N3OH, Cobalt(III), triamminea-quadichloro-, mer-, chloride, 23 110 CoCsNjOgCioHu, Cobaltate(III), [N,N -ethanediyIbis[N-(carboxymethyI)-glycinato](4 - ))-, trans-, cesium,... 

N3C0O6QH12, Cobalt(III), tris(glycinato)-fac- and mer-, 25 135 N3C0O6C9HU, Cobalt(III), tris(alaninato)-fac- and mer-, 25 137 N3F,204P3CioHi4, PoIy[2,2-dimethyI-4,4,6,6-tetrakis(2,2,2-trifluoroethoxy)-catenatriphosphazene-1,6-diyI], 25 67 N3Fi204P3SiCi3H22, PoIy[2-methyl-4,4,6,6-... 

Assign the following to their appropriate point groups, a. tris(oxalato)chromium(lll) b. tris(carbonato)cobalt(III) c. tris(glycinato)cobaIt(III)... 

The compounds studied are the substituted triethylenetetra-aminecobalt(III) amino acid complexes depicted in Figure 1. Formally the A Bj chromophore will be the triethylenetetraamine-cobalt(III) glycinato moiety (compounds 1 and 7, identified in Figure 1) (with an associated configurational effect) and the optically active (Bj) chromophores will be represented by the various R2 substituents at the a-carbon of the chelated glycine... 

OPTICALLY ACTIVE cis-UNIDENTATE-DICARBONATO, ris-m-DIUNIDENTATE-CARBONATO, AND UNIDENTATE GLYCINATO COBALT(III) COMPLEXES... 

CoCIN407C8H2, - 2H20, Cobalt(III), aqua-(glycinato)( 1,4,7-triazacydononane)-, perchlorate, dihydrate, 23 76 CoC1N40,S2C4H,8 H20, Cobalt(III),... 

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