Tokyo Scientists develop switchable chirality in double helix structures

New Delhi: Researchers from Tokyo University of Science have successfully created novel double-helical structures capable of controllable chirality switching. This development could lead to advancements in molecular information processing and high-order molecular systems, paving the way for applications in fields like molecular information transmission, amplification, and replication.

The team, led by Professor Hidetoshi Kawai and including researcher Kotaro Matsumura from the Department of Chemistry, introduced double-helical monometallofoldamers. These structures can reverse their chirality, or “twist,” switching between left-handed (M-form) and right-handed (P-form)—in response to external stimuli like solvents, a breakthrough in controlling the chirality of artificial molecules. This ability to switch chirality is crucial, as it enhances the potential for these molecules to be used in various applications, such as the development of chiral sensors and novel materials with diverse properties.

The research, recently published in the Journal of the American Chemical Society on July 19, 2024, demonstrates how the monometallofoldamers, synthesized from bipyridine-type strands, form double-helical structures with a central zinc cation. These structures exhibit remarkable stability and can dynamically switch between different conformations, responding to temperature changes and solvent environments. The structures favor the double-helix at lower temperatures and the open form at higher temperatures.

A key finding of the study is the ability of these double-helical structures to switch helicity. In non-polar solvents like toluene or hexane, they adopt a left-handed (M-form) structure, while in Lewis basic solvents such as acetone or DMSO, they become right-handed (P-form). The researchers also discovered that when a chiral strand is paired with an achiral strand, the chiral information can be transmitted and amplified, showcasing the potential for these molecules to guide the development of new supramolecular systems that mimic natural structures.

“Our synthesized double-helical monometallofoldamers have the potential to be applied to new switching chiral materials that output diverse chiral properties by small inputs and can be used to develop chiral sensors,” explained Mr. Matsumura. “In addition, we expect that this novel molecular structure will lead to facilitate the genesis of deracemized and organized supramolecular systems as those found in nature by transmitting and amplifying their superior chiral properties.”

This breakthrough represents a significant stride towards creating artificial molecules that can control and switch their structure and properties, offering promising opportunities for future research and applications in material science and molecular engineering.