Delocalization of Coherent Triplet Excitons in Linear Rigid Rod Conjugated Oligomers.
Christian HintzePatrick KorfFrank DegenFriederike SchützeStefan MeckingUlrich E SteinerMalte DrescherPublished in: The journal of physical chemistry letters (2017)
In this work, the triplet state delocalization in a series of monodisperse oligo(p-phenyleneethynylene)s (OPEs) is studied by pulsed electron paramagnetic resonance (EPR) and pulsed electron nuclear double resonance (ENDOR) determining zero-field splitting, optical spin polarization, and proton hyperfine couplings. Neither the zero-field splitting parameters nor the optical spin polarization change significantly with OPE chain length, in contrast to the hyperfine coupling constants, which showed a systematic decrease with chain length n according to a 2/(1 + n) decay law. The results provide striking evidence for the Frenkel-type nature of the triplet excitons exhibiting full coherent delocalization in the OPEs under investigation with up to five OPE repeat units and with a spin density distribution described by a nodeless particle in the box wave function. The same model is successfully applied to recently published data on π-conjugated porphyrin oligomers.
Keyphrases
- energy transfer
- room temperature
- density functional theory
- quantum dots
- single molecule
- photodynamic therapy
- electron transfer
- high resolution
- high speed
- transition metal
- magnetic resonance
- electronic health record
- ionic liquid
- molecular dynamics
- solar cells
- binding protein
- randomized controlled trial
- mass spectrometry
- systematic review
- magnetic resonance imaging
- deep learning