Yoneya Makoto, Makabe Takayoshi, Miyamoto Ayano, Shimizu Yo, Miyake Yasuo, Yoshida Hiroyuki, Fujii Akihiko, Ozaki Masanori
National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568, Japan.
National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorioka, Ikeda, 563-8577, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jun;89(6):062505. doi: 10.1103/PhysRevE.89.062505. Epub 2014 Jun 30.
The structures of the discotic liquid crystalline (LC) phase of metal-free octa-substituted phthalocyanine (Pc) derivatives were investigated using molecular dynamics (MD) simulations. Special attention was paid to the LC phase structure of the non-peripheral octa-hexyl substituted Pc-derivatives that were recently found to show very high carrier mobilities for the discotic LCs. We obtained spontaneous transition to the columnar hexagonal (Col_{h}) LC phase in a melting simulation from the crystal structure obtained using an x-ray diffraction study. In this simulated Col_{h} structure, the Pc-core normal vectors were tilted 47{∘} from the column axis in parallel within each column, but the tilting directions are disordered between columns. We also found that the inter-core distance was not as large as previously suggested (0.4-0.5 nm) but similar to the common value (0.36 nm). This may resolve the contradiction between the high carrier mobility of the non-peripheral substituted Pcs, because larger inter-core separations degrade the mobilities.
使用分子动力学（MD）模拟研究了无金属八取代酞菁（Pc）衍生物的盘状液晶（LC）相结构。特别关注了非周边八己基取代的Pc衍生物的LC相结构，最近发现它们对盘状液晶显示出非常高的载流子迁移率。在使用X射线衍射研究获得的晶体结构的熔化模拟中，我们得到了向柱状六方（Col_h）LC相的自发转变。在这个模拟的Col_h结构中，Pc核法线向量在每列中与列轴平行倾斜47°，但各列之间的倾斜方向是无序的。我们还发现，核间距不像先前建议的那么大（0.4 - 0.5 nm），而是与常见值（0.36 nm）相似。这可能解决了非周边取代Pc的高载流子迁移率之间的矛盾，因为较大的核间距会降低迁移率。
