Related Experiment Video
Updated: Jul 2, 2026
07:03
Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals
Published on: August 15, 2018
Polarization energies in oligoacene semiconductor crystals
Joseph E Norton1, Jean-Luc Brédas
1School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
Journal of the American Chemical Society
|August 22, 2008
Summary
Understanding electronic polarization and nuclear relaxation is key for charge transport in organic solids. This study quantifies these effects in oligoacene crystals using advanced computational methods.
Area of Science:
- Solid-state physics and chemistry
- Computational materials science
- Organic electronics
Background:
- Charge transport in organic solids relies on understanding electronic polarization and nuclear relaxation.
- Oligoacenes are model systems for studying charge carrier behavior in organic materials.
Purpose of the Study:
- To investigate the electronic polarization energies in molecular crystal structures of oligoacenes (naphthalene to pentacene).
- To analyze the evolution of nuclear relaxation energies associated with charge carriers in these systems.
Main Methods:
- Utilized quantum/classical QM/MM (quantum mechanics/molecular mechanics) approaches.
- Employed charge redistribution and polarizable force field schemes for accurate modeling.
- Applied methods to crystalline structures of naphthalene, anthracene, tetracene, and pentacene.
Main Results:
- Comprehensive characterization of electronic polarization energies across different oligoacene crystal structures.
- Calculated nuclear relaxation energies for model oligoacene systems, revealing trends.
Conclusions:
- The study provides fundamental insights into the interplay of electronic and nuclear dynamics governing charge transport.
- Results are crucial for designing and optimizing organic electronic devices.
More Related Videos
Related Concept Videos
01:29Potential Due to a Polarized Object
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
01:28Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:31Dielectric Polarization in a Capacitor
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
03:37Molecular Shape and Polarity
Dipole Moment of a Molecule