Nonequilibrium Molecular Switching of Chiral Helicene Oligomers in Double-Helix Formation.

Nonequilibrium Molecular Switching of Chiral Helicene Oligomers in Double-Helix Formation. Yakugaku Zasshi. 2016;136(12):1591-1600 Authors: Shigeno M Abstract  Molecular switching is the phenomenon in which a molecular structural change occurs reversibly in response to an external stimulus or energy. It plays an important role in biology, in which it is used for sensing environmental changes. In contrast to well-studied equilibrium molecular switching involving thermodynamically stable states, nonequilibrium molecular switching involving a metastable state is a notable chemical phenomenon and is the theme of this study. Sulfonamido- and aminomethylenehelicene oligomers show a reversible structural change from a double helix to a random coil in dilute solution. A metastable state consisting of random coils can be generated by heating, which shows various nonequilibrium thermodynamic properties. Molecular phenomena including molecular thermal hysteresis, molecular memory effect, and one-directional three-state molecular structural change occur, none of which is observed in an equilibrium molecular switching system. They can be applied to sensing environmental changes such as temperature increases/decreases, temperature change rates, and concentration increases, and for counting the numbers 1 and 2. PMID: 27904093 [PubMed - in process]
Source: Yakugaku Zasshi : Journal of the Pharmaceutical Society of Japan - Category: Drugs & Pharmacology Authors: Tags: Yakugaku Zasshi Source Type: research