Katzin effect

The half-wave potentials of K+, Tl+ and Ca2+ in water are slightly more negative and thosefor Zn2+, Cd2+, Mn2+, Ni2+ and Co2+ considerably more negative than is expected according to the donicity rule. It has been shown in the previous sections that water is a rather unique solvent. The effect in question may be interpreted by the so-called Katzin-effect according to which water forms a royal core of coordinated water molecules which are hooked together by hydrogen bonds 70,71>122,1231. 

Bonding effects in circularly dichroic cobalt(III) complexes. L. T. Katzin and I. Eliezer, Coord. Chem. Rev., 1972,7, 331-343 (20). 

Trivalent rare earth cations form complexes with a series of hydroxycarboj lic acids and amino acids in aqueous solutions, some of which are listed in fig. 8. Earlier studies of Katzin (1968, 1969) revealed that these biological substrates effectively act as bidentate ligands toward the rare earth cations. Rare earth complexes with multidentate chelators were recently applied as receptors for zwitterionic amino acids of biological and artificial interests. Aime et al. (2001a) characterized the complexation behaviors of zwitterionic amino acids with oc-... 

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