Liquid Crystals of Phthalocyanine-Fullerene Dyads Exhibiting Homeotropic Alignment and Spiranthes-like Supramolecular Structure Useful for Solar Cells

Tuesday, 26 May 2015: 16:00
Lake Michigan (Hilton Chicago)
A. Watarai, S. N. Yajima, A. Ishikawa, K. Ono (Shinshu University), M. Yasutake (Saitama University), and K. Ohta (Shinshu University)
If liquid crystals of phthalocyanine-fullerene (Pc-C60) dyads would exhibit homeotropic alignment at r.t., they would be very useful for the application to solar cells. Hence, we have synthesized nine novel Pc-C60 dyads, (CnS)6PcCu-Cm-C60 (n = 14, 16, 18; m = 8, 10, 12), to investigate whether they would exhibit perfect homeotropic alignment at r.t. by changing lengths of the peripheral alkylthio chains (Cn) and the spacer chain (Cm) between Pc and C60. As a result, each of them exhibited a hexagonal ordered columnar (Colho) mesophase and the Colho mesophase for n = 14 and m = 8, 10, 12, showed perfect homeotropic alignment in a wide temperature region from r.t. to clearing point. Moreover, the Colho mesophases exhibited spiranthes-like supramolecular structure, which is compatible with one-dimensional nano-array expecting the high conversion efficiency of solar cells.