The replacement of terminal benzimidazole–pyridine binding units in the neutral di- tridentate segmental ligand L1 with phenanthroline in L10 reduces the number of torsional degrees of freedom by two units. Reactions of these ligands with trivalent europium or lutetium cations yield structurally similar self-assembled dinuclear triple-stranded [Ln2 (Lkkk) 3] 6+ complexes, thus demonstrating that the increased rigidity of the strand in L10 is ...
