Thermodynamic properties complexes reacting with

Thermodynamic Properties of Cobalt Complexes Reacting with Oxygen... 

Lanthanide cations, Ln(III), are widely present in nature and based on thermodynamic data, Torres and Choppin (4) have calculated that complexation of Ln(III) by humics could predominate in some organic rich environmental systems and affect the geochemical transport properties of these cations. Ln(III) cations interact predominantly with oxygen donor groups which, in the case of humics, means they react with ionized carboxylate groups. At the pH of natural systems, the phenol groups remain protonated and Ln(III) cations would only interact with them if they (the Ln) are already bound to a neighboring carboxylate. 

When actin and myosin have once combined to give actomyosin, it is not possible by any known method to separate them completely on a preparative scale. There is no doubt, however, that natural actomyosin is really a complex of actin and mj osin, (a) because Straub (1942) obtained in small yield from actomyosin the same actin as obtained from the dry acetone powder of muscle, and (b) natural and artificial actomyosins react with ATP in the same typical manner (Section III, 5d). It can therefore be concluded that complex formation is thermodynamically irreversible, for by repeated fractional precipitation a preparation can be obtained from muscle extracts in which no free L-myosin can be detected by methods at present available. The ultracentrifugal peak of L-myosin reappears, however, when the actomyosin in solution by its history and its properties, e.g., disappearance of ATP-sensitivity, may be regarded as denatured (Portzehl et al., 1950 see also Johnson and Landolt, 1950). 

CSV involves the addition of a ligand of known thermodynamic properties to the solution, equilibration and the accumulation of an adsorbed metal complex on a mercury electrode and its reduction by a cathodic potential scan. CSV measures only the metal species that will react with the ligand, either at the electrode or in solution. The method has found application in ligand competition methods for speciation analysis as discussed below. 

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