0000000000206147

AUTHOR

Michael Wykes

showing 2 related works from this author

Dynamics of guest molecules in PHTP inclusion compounds as probed by solid-state NMR and fluorescence spectroscopy.

2009

Partially deuterated 1,4-distyrylbenzene () is included into the pseudohexagonal nanochannels of perhydrotriphenylene (PHTP). The overall and intramolecular mobility of is investigated over a wide temperature range by (13)C, (2)H NMR as well as fluorescence spectroscopy. Simulations of the (2)H NMR spectral shapes reveal an overall wobble motion of in the channels with an amplitude of about 4 degrees at T = 220 K and 10 degrees at T = 410 K. Above T = 320 K the wobble motion is superimposed by localized 180 degrees flips of the terminal phenyl rings with a frequency of 10(6) Hz at T = 340 K. The activation energies of both types of motions are around 40 kJ mol(-1) which imply a strong steri…

Magnetic Resonance SpectroscopyMolecular StructureSurface PropertiesGeneral Physics and AstronomyNuclear magnetic resonance spectroscopyFluorescence spectroscopyChrysenesInclusion compoundNanostructureschemistry.chemical_compoundNuclear magnetic resonanceSpectrometry FluorescenceSolid-state nuclear magnetic resonancechemistryDeuteriumChemical physicsIntramolecular forceProton NMRMoleculeQuantum TheoryPhysical and Theoretical ChemistryPhysical chemistry chemical physics : PCCP
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Regio(ir)regular naphthalenediimide- and perylenediimide-bithiophene copolymers: How MO localization controls the bandgap

2016

Absorption spectra of regio(ir)regular naphthalenediimide (NDI)- and perylenediimide (PDI)-bithiophene (2T) donor/acceptor (D/A) copolymers are surprisingly similar despite cross-conjugation in the regioirregular structures. This result is traced back to largely localized frontier molecular orbitals (FMOs) as revealed by (time-dependent) DFT calculations. Interestingly, while the FMOs of the P(PDI-2T) copolymer are localized solely in the PDI units, they are predominantly localized in the respective D/A units of the P(NDI-2T) copolymer. The pronounced CT character of the lowest singlet state in P(NDI-2T) should give rise to a close lying CT triplet state, generating small singlet–triplet ga…

Absorption spectroscopyOrganic solar cellBand gapChemistry02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesAcceptor0104 chemical sciencesMaterials ChemistryCopolymerMolecular orbitalSinglet stateTriplet state0210 nano-technology
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