Observation of the missing mode effect in a poly-phenylenevinylene derivative: Effect of solvent, chain packing, and composition
- 1 November 2010
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 133 (17), 174901
- https://doi.org/10.1063/1.3500658
Abstract
Optical emission spectra of poly[2-methoxy-5-[ 3 ′ , 7 ′ -dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) in dilute solutions exhibit a vibronic progression interval ( ∼ 1225 cm − 1 ) that does not correspond to any ground state vibrational mode frequency. This phenomenon is assigned as the missing mode effect (MIME) in which five key displaced polymer backbone vibrational modes in the range of 800 – 1600 cm − 1 contribute to the MIME interval. Emission spectra are calculated by analytically solving the time-dependent Schrödinger equation using estimates of mode-specific vibrational displacements determined independently from preresonance Raman intensities. Emission spectra of MDMO-PPV thin films and nanoparticles are measured and lineshapes show an increase of the MIME frequency to ∼ 1340 cm − 1 in addition to changes in vibronic intensity distributions and energies. Composite blend thin films consisting of MDMO-PPV and a fullerene derivative (1:1 w/w) exhibit a substantially larger MIME interval ( ∼ 1450 cm − 1 ) that arises from an increase in polymer chain planarity. This structural change is most apparent from large decreases of the excited state displacement of an out-of-plane C H bending mode ( 961 cm − 1 ) that becomes forbidden in the planar structure.This publication has 46 references indexed in Scilit:
- Electroluminescence from Charge Transfer States in Polymer Solar CellsJournal of the American Chemical Society, 2009
- Optical Spectroscopy of a Polyfluorene Copolymer at High Pressure: Intra- and Intermolecular InteractionsPhysical Review Letters, 2007
- Effects of Photo‐oxidation on the Performance of Poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene vinylene]:[6,6]‐Phenyl C61‐Butyric Acid Methyl Ester Solar CellsAdvanced Functional Materials, 2006
- Single-Molecule Spectroscopy of Conjugated PolymersAccounts of Chemical Research, 2005
- Dual Species Emission from Single Polyfluorene Molecules: Signatures of Stress-Induced Planarization of Single Polymer ChainsJournal of the American Chemical Society, 2005
- Apparent vibrational side bands in-conjugated systems: The case of distyrylbenzenePhysical Review B, 2005
- Excitonic Solar CellsThe Journal of Physical Chemistry B, 2003
- Origins of aggregation quenching in luminescent phenylenevinylene polymersJournal of Photochemistry and Photobiology A: Chemistry, 2001
- Unusual spectroscopic features in the emission and absorption spectra of single-crystal potassium tetrachloroplatinate(II) (K2[PtCl4]) caused by multiple-mode excited-state distortionsJournal of the American Chemical Society, 1988
- The MIME effect: absence of normal modes corresponding to vibronic spacingsInorganic Chemistry, 1982