Fingerprints of Through-Bond and Through-Space Exciton and Charge π-Electron Delocalization in Linearly Extended [2.2]Paracyclophanes.
J Am Chem Soc
; 139(8): 3095-3105, 2017 03 01.
Article
in En
| MEDLINE
| ID: mdl-28170229
ABSTRACT
New stilbenoid and thiophenic compounds terminally functionalized with donor-donor, acceptor-acceptor, or donor-acceptor moieties and possessing a central [2.2]paracyclophane unit have been prepared, and their properties interpreted in terms of through-bond and through space π-electron delocalization (i.e., π-conjugations). Based on photophysical data, their excited-state properties have been described with a focus on the participation of the central [2.2]paracyclophane in competition with through-bond conjugation in the side arms. To this end, two-photon and one-photon absorption and emission spectroscopy, as a function of temperature, solvent polarity, and pressure in the solid state have been recorded. Furthermore, charge delocalization through the [2.2]paracyclophane in the neutral state and in the oxidized species (radical cations, dications and radical trications) has been investigated, allowing the elucidation of the vibrational Raman fingerprint of through-space charge delocalization. Thus, a complementary approach to both "intermolecular" excitation and charge delocalizations in [2.2]paracyclophane molecules is shown which can serve as models of charge and exciton migration in organic semiconductors.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Am Chem Soc
Year:
2017
Document type:
Article
Affiliation country:
Spain