Carbonato complexes stability constants

The stability constants of several carbonato complexes of metal ions in solution has been compiled (3). Several recent publications have dealt with the isolation and characterization of carbonato complexes... 

Other Coordination Complexes. Because carbonate and bicarbonate are commonly found under environmental conditions in water, and because carbonate complexes Pu readily in most oxidation states, Pu carbonato complexes have been studied extensively. The reduction potentials vs the standard hydrogen electrode of Pu(VI)/(V) shifts from 0.916 to 0.33 V and the Pu(IV)/(III) potential shifts from 1.48 to -0.50 V in 1 M carbonate. These shifts indicate strong carbonate complexation. Electrochemistry, reaction kinetics, and spectroscopy of plutonium carbonates in solution have been reviewed (113). The solubility of Pu(IV) in aqueous carbonate solutions has been measured, and the stability constants of hydroxycarbonato complexes have been calculated (Fig. 6b) (90). 

The previously unknown carbonato-complex [Ir(C03)(NH3)5]C104 has been isolated by treating [Ir(NH3)5(H20)](C104)3 with aqueous Li2C03 at pH 8.5, and the kinetics of its formation and aquation were studied.174 Stability constants have been measured using pH titration for a variety of o-coumaric acid complexes, including a 1 3 species with Ir111.74... 

Figure 3. Titration data for complexation of copper by carbonate. Solution contained lOmM NaHCOs and 5/xM CuSO. pH varied by adjusting Pco Curve calculated according to hydroxo and carbonato stability constants determined in...

The logarithms of the stability constants fly for the formation of 1 1 complexes of the actinide ions M +, M " ", MOj and MO with various inorganic ligands are plotted in Fig. 21.1. Carbonato complexes of alkaline-earth elements, lanthanides, actinides and other transition elements play an important role in natural waters and may stabilize oxidation states. 

Figure 10.19. Speciation of Pb(II) in the Glatt River. The concentrations given for CO2, Pb(II), Cu(II), and [Ca ] as well as for the pollutants EDTA and NTA are representative of concentrations encountered in this river. The speciation is calculated from the surface complex formation constants determined with the particles of the river and the stability constants of the hydroxo, carbonato, NTA, and EDTA complexes. The presence of [Ca " ] and [Cu " ] is considered. (From Muller and Sigg, 1990.)...

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