Unravelling self-assembly of lanthanide helicates: Switching from deduction to induction

Classical supramolecular approach involving thermodynamic and kinetic characterisation is discussed for polymetallic lanthanide complexes with neutral ligands. These experimental studies allow (i) to obtain the stability constants of the self-assembled species and (ii) to establish the formation mechanism. Consequently, the analysis of these data with thermodynamic models promotes a deeper rationalization of self-assembly. The quantitative energetic parametrization of inter- and intra-molecular processes together with intermetallic and interligand interactions is obtained for europium(III) complexes of similar structure. To confirm the predictive ability of this thermodynamic modelling, the stability constant of the homologous tetrametallic helicate [Eu4(L4)3]12+ has been computed. An excellent agreement between the predicted and the experimental value of β4,3Eu,L4 demonstrates the power of this innovative approach for supramolecular programming.