alpha-cyclodextrin: A molecule for testing colorimetric reversibility of polydiacetylene supramolecules

Abstract

A receptor molecule, α cyclodextrin (α-CD) that can be used to distinguish between two types of polydiacetylenes (PDA) supramolecules that undergo colorimetric changes was studied. α-CD was found to promote a blue-to-purple or blue-to-red color transition of only those PDAs that are colorimetrically irreversible. Color changes of solutions containing 1 mM of PDAs derived from 1-9 containing 10 mM of Cds were monitored in order to investigate the relationship between colorimetric reversibility and Cd-PDA interactions. It was observed that the removal of internal hydrogen bonding amide groups has an important effect on the ability of CDs to promote the colorimetric change of PDAs. The absence of aromatic interactions is also important in determining whether or not α-CD induces a PDA color change. It was also observed that α-CD was unable to induce a color change of PDAs that display a reversible thermochromism behavior.