Supramolecular Chirogenesis Induced by Platinum(II) Tweezers with Excellent Environmental Tolerance.

Supramolecular chirogenesis has emerged as an effective strategy to access symmetry breaking in artificial systems. However, the chirogenic signals suffer from high susceptibility toward environmental variations, which are disadvantageous for their applications in asymmetric catalysis, chiroptical devices etc. Herein an effective strategy has been developed to address this issue, by constructing non-covalent tweezer/guest complexes stabilized by two-fold donor-acceptor and Pt(II)---Pt(II) metal-metal interactions. Upon guest encapsulation, the two pincers on achiral Pt(II) tweezer undergo stereospecific twist to minimize steric repulsion, thus locking the tweezer/guest complexes into preferred chiral conformations. The induced chiroptical effects display outstanding solvent- and temperature- tolerance, ascribed to strong tweezer/guest binding strength via the balance between electrostatic and desolvation effects for the involved non-covalent interactions. Moreover, hierarchical and multi-component supramolecular assembly of tweezer/guest complexes provide a convenient way to modulate chirogeneic signals for their intensities. Overall, the current study opens up new avenues toward artificial supramolecular chirogenesis with excellent environmental tolerability.