Paper Citing NAMD - Abstract
Zhang, Afang; Rodriguez-Ropero, Francisco; Zanuy, David; Aleman, Carlos; Meijer, E. W.; Schlueter, A. Dieter
A rigid, chiral, dendronized polymer with a thermally stable, right-handed helical conformation
CHEMISTRY-A EUROPEAN JOURNAL, 14:6924-6934, 2008
First- and second-generation dendronized polymethacrylates PG1 and PG2 carrying chiral 4-aminoproline-based dendrons were obtained on the half-gram scale in high molar masses (PG1: M(n) = 5 x 10(6) g mol(-1), PG2: M(n) = 1 x 10(6) mol(-1)) by spontaneous (radical) polymerization of the corresponding vinyl macromonomers. NMR spectroscopic studies on PG2 together with its unprecedented high glass transition temperature (T(g) > 200 degrees C, decomp) and structural parameters provided by atomistic MD simulations show this polymer to be rather rigid. Optical rotation and CD measurements revealed that PG2 adopts a helical conformation that remains unchanged over wide ranges of temperature and solvent polarity. It is also retained when the polymer is deprotected (and thus positively charged, de-PG2) at its terminal amino groups. by which the mass and steric demand of the dendrons is reduced by roughly 50%. Molecular dynamics simulations on models of PG2 reveal its helical conformation to be right-handed, irrespective of backbone tacticity, and initial results also indicate that de-PG2 retains the right-handedness.
