"Inverse" thermoresponse: heat-induced double-helix formation of an ethynylhelicene oligomer with tri(ethylene glycol) termini.

ABSTRACT: An ethynylhelicene oligomer [(M)-d-4]-C₁₂-TEG with six tri(ethylene glycol) (TEG) groups at the termini was synthesized, and double-helix formation was studied using CD, UV-Vis, vapor pressure osmometry, dynamic light scattering, and ¹H NMR. [(M)-d-4]-C₁₂-TEG reversibly changed its structure between a double helix and a random coil in response to heating and cooling in aromatic solvents, non-aromatic polar organic solvents, and aqueous solvent mixtures of acetone/water/triethylamine. Notably, [(M)-d-4]-C₁₂-TEG in acetone/water/triethylamine (1/2/1) formed a double helix upon heating and disaggregated into random coils upon cooling. The double helix/random coil ratio sharply changed in response to temperat

SUBMITTER: Saito N 

PROVIDER: S-EPMC6007355 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature