Artificial molecular rotors that perform sophisticated rotary motions have attracted considerable interest in the context of molecular machines, particularly because they stand out as essential components for complex machine-like functions in biological systems.
Hiroki Iida, Stephan Irle, Eiji Yashima, and colleagues, Shimane University and Nagoya University, Japan, synthesized organic compounds that form double-stranded helices, covalently bridged by two cyclic boronate esters (structure partially pictured above, X = aromatic spacer unit). The two cyclic boronate ester units encased in the double-stranded helical framework dynamically rotate. Therefore, the double helices function as unprecedented artificial molecular rotors composed of multi-rotators covalently linked to a double helical stator.
The helically twisted stator could also perform an interconvertible helical inversion motion concurrently with the rotation of the cyclic boronate ester units. This provides a molecular rotor that undergoes dual rotary and inverting (twisting) motions. These findings could prove beneficial in developing optically active molecular rotors by introducing chiral substituents on the boronate ester units.
- Double-Stranded Helical Oligomers Covalently-Bridged by Rotary Cyclic Boronate Esters,
Hiroki Iida, Kenji Ohmura, Ryuta Noda, Soichiro Iwahana, Hiroshi Katagiri, Naoki Ousaka, Taku Hayashi, Yuh Hijikata, Stephan Irle, Eiji Yashima,
Chem. Asian J. 2017.