Development of robust chiroptical systems through spirobifluorenes

Chiroptical responses are valuable for the structural determination of dissymmetric molecules. However, the development of everyday applications based on chiroptical systems is yet to come. We have been earlier using axially chiral allenes for the construction of linear, cyclic, and cage‐shaped molecules that present remarkable chiroptical responses. Additionally, we have developed chiral surfaces through upstanding chiral architectures. Since the goal is to obtain robust chiroptical materials, more recently we have been studying spirobifluorenes (SBFs), a well‐established building block in optoelectronic applications. After theoretical and experimental demonstration, the suitability of chiral SBFs for the development of robust chiroptical systems was certified by the construction all‐carbon double helices, flexible shape‐persistent macrocycles, chiral frameworks for surface functionalization, and structures featuring helical or spiroconjugated molecular orbitals. Here, we give an overview of our contribution to these matters. Chiral spirobifluorenes (SBFs) can be used to create chiroptical systems with high thermal stability and chiroptical responses. Some recent examples are as follows: SBFs with metal‐containing aromatic rings, tetracyanobutadiene SBFs, SBFs with tunable spiroconjugation, all‐carbon double helices, flexible shape‐persistent macrocycles, and macrocycles presenting helical molecular orbitals.