Dicarbonato complexes

The trans isomers of the dicarbonato, carbonatooxalato and bis(oxalato) complexes have a split second absorption band (Ha and IIb) the extent of the splitting is greatest for the dicarbonato complex and smallest for the bis(oxalato) complex (Fig. 5.5). The franj(N)-bis(malonato) complex, showed no splitting in either the... 

The absorption and CD spo tral data are collected in Tables 5.9 and 5.10. The CD spectra could be grouped into four types of patterns in the Tjg region 1) only one peak, 2) two peaks of opposite signs, 3) two peaks of the same sign, and 4) three peaks of alternating sign. The active dicarbonato complexes exhibit a symmetrical peak of type 1. The active carbonatooxalato complexes also show only one peak, which is unsymmetrical. The (+)s89[Co(C03)(mal)(NH3)2] complex exhibits the pattern of type 2. The (—)546[Co(ox)2(en)] complex has the pattern of type 3. The active oxalatomalonato and bis(malonato) complexes show the pattern of type 4. 

In the case of plutonyl(VI), somewhat more plausible results have been obtained. Data on the solubility of plutonyl(VI) hydroxide in (NHit)2C03 solutions of varying concentrations have been interpreted (11) to reveal the presence of three complexes, Pu02(C03) , Pu02(C03)(OH) , and Pu02(CO3)(OH) ", with stability constants of 6.7 X 10, 4.5 X 10, and 2.3 X 10, at I = 1 M and 20°. The value for the dicarbonato species is reasonably consistent with published constants for the analogous uranyl(VI) species, but the constants for the hydroxy species need further verification. 

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

Most of the complexes with C0N2O4 chromophores so far prepared contain the N-donor as amino-acidate, iminodiacetate, or nitrilotriacetate, and the first absorption bands of their tranj(N) isomers are explicitly split. However, trans(N) complexes that exhibit splitting not in the first but in the second absorption band were isolated, from the reaction of the green solution and pyridine, as crystals of trans- and m-[Co(C03)2(py)2] - From the mixture of the dicarbonato-oxalatocobaltate(III) and pyridine, rrans-[Co(C03)(ox)(py)2] was obtained. The reactions of pyridine on aqueous solutions of tris(oxalato)cobaltate(III) and tris-(malonato)cobaltate(III) resulted in trans- and cis-[Co(ox)2(py)2] and trans- and cw-[Co(mal)2(py)2l , respectively. 

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