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Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Can octupolar molecules be poled by an external electric field?
Yaoquan Tu1, Yi Luo, Hans Agren
1Theoretical Chemistry, Royal Institute of Technology, Alba Nova University Center, S-10691 Stockholm, Sweden.
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Octupolar molecules, like TATB, develop significant solution dipole moments due to thermal motion and interactions, allowing electric fields to influence their orientation. This challenges the idea that electric fields cannot effectively order these molecules for nonlinear optical applications.
Area of Science:
- Materials Science
- Computational Chemistry
- Nonlinear Optics
Background:
- Octupolar molecules are explored for nonlinear optical (NLO) materials due to limited aggregation.
- A perceived drawback is the inability of electric fields to align molecules lacking a permanent dipole moment.
- The 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) molecule serves as a model for octupolar systems.
Purpose of the Study:
- To investigate the effect of electric fields on octupolar molecules in solution.
- To challenge the notion that electric fields have no poling effect on octupolar molecules.
- To analyze the collective NLO properties of octupolar molecules under an applied electric field.
Main Methods:
- Molecular dynamics simulations of TATB molecules in chloroform.
- Analysis of dipole moments, molecular orientations, and aggregation behavior.
- Integration of quantum chemistry results to assess NLO properties.
Main Results:
- TATB molecules exhibit significant induced dipole moments in solution.
- Thermal motion and intermolecular interactions contribute to these induced dipoles.
- Applied electric fields effectively influence the orientation of molecular dipoles.
- TATB molecules can aggregate via hydrogen bonding despite lacking a static permanent dipole.
- Collective NLO properties are enhanced by electric fields, showing anisotropy.
Conclusions:
- Octupolar molecules can develop significant dipole moments in solution, enabling electric field poling.
- The aggregation behavior of octupolar molecules is influenced by factors beyond static dipole moments.
- Simulation results offer a new perspective on the collective properties and NLO potential of octupolar molecules.
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