Nine novel organolanthanoid (Ln=Pr and Yb) complexes of the general type [LnCp′2(μ-OCHR(1)Z)]2 (Cp′=C5H5 or CH3C5H4, R(1)=H or Me) containing exclusively chiral, oxygen-functionalized alkoxide ligands with Z(1)=CHR(2)OMe (R(2)=Me or Ph), Z(2)=COOiBu and Z(3)=CH2COOEt have been prepared and further characterized. While five (of six) Pr complexes give rise to solution 1H-NMR spectra indicative of stable (on the NMR time scale) intramolecular coordination of Z via an additional O→Pr bond (as in form B of Fig. 1Fig. 1Schematic view of the two structural alternatives A and B to be expected for all title complexes.), the corresponding Yb-homologues turn out to be fluxional at room temperature. In contrast, X-ray diffraction studies of two new representatives with Ln=Yb, and of one selected complex with Ln=Pr, confirm the earlier suggested view (Steudel et al., J. Organomet. Chem. 556 (1998) 229) that in the solid state the central Ln(III) ion adopts the highest possible coordination number.