%0 journal article
%@ 0014-3057
%A Traiphol, R., Srikhirin, T., Kerdcharoen, T., Osotchan, T., Scharnagl, N., Willumeit, R.

%D 2007
%J European Polymer Journal
%N 2
%P 478-487 
%R doi:10.1016/j.eurpolymj.2006.11.022
%T Influences of local polymer-solvent p-p-interaction on dynamics of phenyl ring rotation and its role on photophysics of conjugated polymer
%U https://doi.org/10.1016/j.eurpolymj.2006.11.022
2 
%X In this report, the role of local polymer–solvent π–π-interaction on rotational dynamics of phenyl rings of poly[2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylenevinylene] (MEH-PPV) is examined by utilizing nuclear magnetic resonance (NMR) spectroscopy. We have found that an aromatic solvent can couple strongly with the phenyl rings via favorable local π–π-interaction, causing a restriction of the ring rotation. The dynamic process takes place at much faster rate in a non-aromatic solvent. NMR line shape analysis indicates the existence of two side chain configurations with relatively long life-time in toluene and pyridine while a single time-averaged configuration is detected in chloroform and tetrahydrofuran. Addition of chloroform or cyclohexane to a solution of MEH-PPV in toluene is accompanied by an increase of the rotational dynamics. This indicates that the expansion or collapse of main chain upon varying solvent quality play a minor role on the rotational dynamics. The relationship between the dynamics of ring rotation and photophysics of MEH-PPV in solution is discussed.