Self-Discriminating Self-Assembly of Dinuclear Heterochiral Rhombs from Tröger’s Base Derived Bis(pyridyl) Ligands

Five racemic dissymmetric bis(pyridyl) ligands based on 2,8- or 3,9-difunctionalised Tröger's base derivatives have been synthesised. Only those derived from a 2,8-difunctionalised scaffold were found to undergo selective self-assembly to discrete self-assembled dinuclear metallosupramolecular aggregates of rhomboid shape upon coordination to cis-protected Pd(2+) or Pt(2+) ions, as evidenced by ESI mass spectrometry, NMR spectroscopy and single-crystal X-ray diffraction. Interestingly, these processes were found to be highly diastereoselective leading to the formation of C(2v)-symmetric heterochiral assemblies in a self-discriminating manner.