Abstract
Non-covalent interactions determine in large part the thermodynamic aspects of molecular packing in organic crystals. Using a combination of symmetry-adapted perturbation theory (SAPT) and classical multipole electrostatics, we describe the interaction potential energy surfaces for dimers of the oligoacene family, from benzene to hexacene. An analysis of these surfaces and a thorough assessment of dimers extracted from the reported crystal structures underline that high-order interactions (i.e., three-body non-additive interactions) must be considered in order to rationalize the details of the crystal structures. A comparison of the SAPT electrostatic energy with the multipole interaction energy demonstrates the importance of the contribution of charge penetration, which is shown to account for up to 50% of the total interaction energy in dimers extracted from the experimental single crystals; in the case of the most stable co-facial model dimers, this contribution is even larger than the total interaction energy. Our results highlight the importance of taking account of charge penetration in studies of the larger oligoacenes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3990-4000 |
| Number of pages | 11 |
| Journal | Chemistry of Materials |
| Volume | 28 |
| Issue number | 11 |
| DOIs | |
| State | Published - May 26 2016 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledged KAUST grant number(s): N62909-15-1-2003
Acknowledgements: This work has been supported by King Abdullah University of Science and
Technology (KAUST), the KAUST Competitive Research Grant program, and the Office of
Naval Research Global (Award N62909-15-1-2003). We acknowledge the IT Research
Computing Team and Supercomputing Laboratory at KAUST for providing computational and
storage resources. This work has also used the computing resources of the Garnet, Spirit, and
Copper supercomputing systems through the DoD HPCMP. We wish to thank Prof. C. David
Sherrill, Dr. Rob Parrish, and Mr. Trent Parker for technical assistance and stimulating
discussions.