10.1021/jp108546w.s001 Takuji Adachi Takuji Adachi Johanna Brazard Johanna Brazard Paresh Chokshi Paresh Chokshi Joshua C. Bolinger Joshua C. Bolinger Venkat Ganesan Venkat Ganesan Paul F. Barbara Paul F. Barbara Highly Ordered Single Conjugated Polymer Chain Rod Morphologies American Chemical Society 2010 polarization anisotropy values chain simulations tetrahedral chemical defects fraction fluorescence polarization anisotropy Single Conjugated Polymer Chain Rod MorphologiesWe polarization values PMMA polymer chains 2010-12-09 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Highly_Ordered_Single_Conjugated_Polymer_Chain_Rod_Morphologies/2706280 We have reexamined the fluorescence polarization anisotropy of single polymer chains of the prototypical conjugated polymer poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) isolated in a poly(methyl methacrylate) (PMMA) matrix employing improved synthetic samples that contain a much smaller number of tetrahedral chemical defects per chain. The new measurements reveal a much larger fraction of highly anisotropic MEH-PPV chains, with >70% of the chains exhibiting polarization anisotropy values falling in the range of 0.6−0.9. High anisotropy is strong evidence for a rod-shaped conformation. A comparison of the experimental results with coarse grain, beads on a chain simulations reveals that simulations with the usual bead−bead pairwise additive potentials cannot reproduce the observed large fraction of high polarization values. Apparently, this type of potential lacks some yet to be identified molecular feature that is necessary to accurately simulate the experimental results.