Dynamics of side chains in poly(quinoxaline-2,3-diyl)s studied via quasielastic neutron scattering

Inoue, Rintaro*; Nagata, Yuya*; Tominaga, Taiki*; Sato, Sota*; Kawakita, Yukinobu  ; Yamawaki, Tomonori*; Morishima, Ken*; Suginome, Michinori*; Sugiyama, Masaaki*

The side chain dynamics of poly(quinoxaline-2,3-diyl)s (PQXs) are expected to influence their conformation. To investigate these dynamics experimentally, quasielastic neutron scattering (QENS) was performed for PQXs in deuterated tetrahydrofuran (THF-) and deuterated 1,1,2-trichloroethane/THF (1,1,2-TCE-/THF-), in which they formed right-handed and left-handed helical structures, respectively. The mean-square displacement of the PQX side chains in 1,1,2-TCE-/THF- was lower than that in THF-. Furthermore, QENS complementary studies and molecular dynamics simulations unraveled a coupling between the main-chain and side chain dynamics of PQXs, suggesting the possibility of controlling the main-chain helical chirality through the dynamics of chiral side chains. These insights present a novel strategy for the design of synthetic helical macromolecules with precise chirality control.