Toward ultralow-bandgap liquid crystalline semiconductors: use of triply fused metalloporphyrin trimer-pentamer as extra-large π-extended mesogenic motifs

Seiya Tanaka; Tsuneaki Sakurai; Yoshihito Honsho; Akinori Saeki; Shu Seki; Kenichi Kato; Masaki Takata; Atsuhiro Osuka; Takuzo Aida

doi:10.1002/chem.201201101

Toward ultralow-bandgap liquid crystalline semiconductors: use of triply fused metalloporphyrin trimer-pentamer as extra-large π-extended mesogenic motifs

Chemistry. 2012 Aug 20;18(34):10554-61. doi: 10.1002/chem.201201101. Epub 2012 Jul 12.

Authors

Seiya Tanaka¹, Tsuneaki Sakurai, Yoshihito Honsho, Akinori Saeki, Shu Seki, Kenichi Kato, Masaki Takata, Atsuhiro Osuka, Takuzo Aida

Affiliation

¹ Department of Chemistry and Biotechnology, School of Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.

PMID: 22791554
DOI: 10.1002/chem.201201101

Abstract

In contrast with their dimeric homologue, triply fused zinc porphyrin trimer-pentamer, as extra-large π-extended mesogens, assemble into columnar liquid crystals (LCs) when combined with 3,4,5-tri(dodecyloxy)phenyl side groups (3 P(Zn) -5 P(Zn) , Figure 1). Their LC mesophases develop over a wide temperature range, namely, 41-280 °C (on heating) for 5 P(Zn) , and all adopt an oblique columnar geometry, typically seen in columnar LC materials involving strong mesogenic interactions. These LC materials are characterized by their wide light-absorption windows from the entire visible region up to a near infrared (NIR) region. Such ultralow-bandgap LC materials are chemically stable and serve as hole transporters, in which 5 P(Zn) gives the largest charge carrier mobility (2.4×10(-2) cm V(-1) s(-1) ) among the series. Despite a big dimensional difference, they coassemble without phase separation, in which the resultant LC materials display essentially no deterioration of the intrinsic conducting properties.