School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.
J Am Chem Soc. 2014 Apr 30;136(17):6421-7. doi: 10.1021/ja501725s. Epub 2014 Apr 22.
Polarization energy corresponds to the stabilization of the cation or anion state of an atom or molecule when going from the gas phase to the solid state. The decrease in ionization energy and increase in electron affinity in the solid state are related to the (electronic and nuclear) polarization of the surrounding atoms and molecules in the presence of a charged entity. Here, through a combination of molecular mechanics and quantum mechanics calculations, we evaluate the polarization energies in two prototypical organic semiconductors, pentacene and 6,13-bis(2-(tri-isopropylsilyl)ethynyl)pentacene (TIPS-pentacene). Comparison of the results for the two systems reveals the critical role played by the molecular packing configurations in the determination of the polarization energies and provides physical insight into the experimental data reported by Lichtenberger and co-workers (J. Amer. Chem. Soc. 2010, 132, 580; J. Phys. Chem. C 2010, 114, 13838). Our results underline that the impact of packing configurations, well established in the case of the charge-transport properties, also extends to the polarization properties of π-conjugated materials.
极化能对应于原子或分子从气相到固态时阳离子或阴离子状态的稳定化。在带电荷实体存在的情况下，固体中电离能的降低和电子亲合能的增加与周围原子和分子的（电子和核）极化有关。在这里，我们通过分子力学和量子力学计算的组合，评估了两种典型有机半导体（并五苯和 6,13-双（2-（三异丙基乙炔基）乙炔基）并五苯（TIPS-并五苯））中的极化能。对两个系统的结果进行比较，揭示了分子堆积构型在确定极化能方面所起的关键作用，并为 Lichtenberger 及其同事报告的实验数据提供了物理见解（J. Amer. Chem. Soc. 2010, 132, 580; J. Phys. Chem. C 2010, 114, 13838）。我们的结果强调了堆积构型的影响，在电荷输运性质的情况下已经得到很好的确立，也扩展到了π共轭材料的极化性质。
