Yttrium(III) bonding to organic ligands: A comparison with the lanthanoid(III) cations

摘要

The yttrium(III) bonding to organic substrates (oximes, β-diketonates and (poly)amino-(poly)carboxylates) has been compared with that of the lanthanoid(III) cations. The complexation constants of Y3+with the examined organic ligands are similar to those of some cations of the first half of the lanthanoid series, in contrast with the fact that the Y3+ionic dimensions are similar to those of Ho3+. This has been explained by correlating the formation constants of the Y3+and the lanthanoids(III) complexes by the equation logK1=CACB+EAEB, where the parametersCandEindicate the tendency of each Lewis acidAand Lewis baseBto undergo covalent or ionic bonding, and where the ratioH=E/Cindicates the charge control on the bond formation tendency of each speciesAorB. The results are commented in terms of the utility of Y3+in assisting organic reactions