Related Experiment Video
Updated: Jan 21, 2026

Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids
Published on: August 23, 2012
Quadrupolar Cyclopenta[hi]aceanthrylene-Based Electron Donor-Acceptor-Donor Conjugates: Charge Transfer versus Charge
Christoph Schierl1, Wiebke Alex1, Luis M Mateo2,3,4
1Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität, Erlangen-Nürnberg, Egerlandstr. 3, 91058, Erlangen, Germany.
Abstract:
Cyclopenta[hi]aceanthrylenes (CPAs) have been functionalized at two of the peripheral positions with electronically inert trimethylsilylethynyl (1), as well as with electron-donating 4-ethynyl-N,N-dimethylaniline (2), ethynyl ZnII phthalocyanine (3), and ethynyl ZnII porphyrin (4) units. Consistent with X-ray crystal structures of 2 and 4, analyses of absorption and fluorescence of 2-4 point to strong electronic communication between the CPA and the peripheral units, affording quadrupolar electron donor-acceptor-donor charge-transfer conjugates. By virtue of their quadrupolar/dipolar charge-transfer characters in the excited state, 2-4 exhibit fluoro-solvatochromism. Transient absorption spectroscopy confirmed delocalized quadrupolar ground states and formation of weakly solvent stabilized quadrupolar singlet excited states. The latter transform into strongly stabilized dipolar excited states before deactivating to the ground state in 2 and give rise to a fully charge separated state in 3 and 4.
Related Concept Videos
Formal Charges
Ions and Ionic Charges
Atomic Radii and Effective Nuclear Charge
Trends in Lattice Energy: Ion Size and Charge
Electric Charges
The English physicist William Gilbert studied the phenomenon of static electricity in...
Charge on a Conductor

