Metallosupramolecular Architectures of Ambivergent Bis(Amino Acid) Biphenyldiimides.

The metallosupramolecular chemistry of two enantiopure dicarboxylate ligands has been explored for their potential to form discrete or polymeric interlocked motifs. Consequently, both discrete and polymeric supramolecular complexes have been synthesised, yielding M2 L2 metallomacrocycles (1 and 2), a heteroleptic M2 L3 metallomacrobicycle (3), a non-interpenetrated coordination polymer (4), and highly unusual chiral M8 L8 squares (5 and 6). There appears to be a preference for the ligands to form M2 L2 -type metallomacrocyclic structural units (which feature in 1-4), although these do not engage in any mechanical interlocking, which is perhaps a combined function of the ligand flexibility and relatively small pi-surface contrasted to previous analogues. Using copper paddlewheel SBUs, chiral double-walled squares (5 and 6) are formed with large internal cavities yet poor stabilities, unexpectedly featuring the paddlewheel motifs at the vertices of the polygonal complex.