Conformational Analysis of Oxygen Induced Higher Ordered Structure of A, B Alternating Poly(arylene vinylene) Copolymers by Solid State NMR and Molecular Dynamics Simulations
Two types of poly(arylene vinylene) copolymer derivatives, one containing heptoxy side chains and the other containing octyl side chains, are investigated by solid state nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulation in order to understand the effect of the chemical structure of the side chains on the molecular packing structure and the charge transport properties. Solid state NMR study shows that octyl functionalized polymer has higher side chain mobility, indicating a higher degree of molecular stacking disorder than heptoxy functionalized polymer. MD simulations suggest that these differences in molecular packing and mobility are associated with the different side chain geometry. Overall, we demonstrate how the new poly(arylene vinylene) copolymer derivatives with a small change in polymer side chain (alkyl vs alkoxy) lead to large changes in the molecular packing arrangement and thereby the improved hole mobility in organic thin film transistors.