Effect of Fluoroalkyl-Substituent in Bistolane-Based Photoluminescent Liquid Crystals on Their Physical Behavior

Crystals

Toshio Kubota¹  Tomohiro Agou¹  Masakazu Nagata¹  Hiroki Fukumoto¹  Yizhou Wang²  Masato Morita²  Tsutomu Konno²  Shigeyuki Yamada²  Mitsuo Hara³  David O’Hagan⁴  Qingzhi Zhang⁴ 

[1] Department of Quantum Beam Science, Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Naka-narusawa, Hitachi, Ibaraki 316-8511, Japan;Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan;Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan;School of Chemistry, University of St. Andrews, North Haugh, St. Andrews KY 15 5EA, UK;

关键词: alkyl;    bistolane;    fluoroalkyl;    flexible chain;    liquid crystal;    photoluminescence;   

DOI  :  10.3390/cryst11040450

来源: DOAJ

【 摘 要 】

Photoluminescent liquid crystals (PLLCs) have attracted significant attention owing to their broad applicability in thermosensing and PL switching. Extensive efforts have been made to develop bistolane-based PLLCs containing flexible units at both molecular terminals, and it has been revealed that their PL behavior can switch with the phase transition between the crystalline and LC phases. Although slight modulation of the flexible unit structure dramatically alters the LC and PL behaviors, few studies into the modification of the flexible units have been conducted. With the aim of achieving dynamic changes in their physical behaviors, we developed a family of bistolane derivatives containing a simple alkyl or a fluoroalkyl flexible chain and carried out a detailed systematic evaluation of their physical behaviors. Bistolanes containing a simple alkyl chain showed a nematic LC phase, whereas switching the flexible chain in the bistolane to a fluoroalkyl moiety significantly altered the LC phase to generate a smectic phase. The fluoroalkyl-containing bistolanes displayed a stronger deep blue PL than their corresponding non-fluorinated counterparts, even in the crystalline phase, which was attributed to the construction of rigid molecular aggregates through intermolecular F···H and F···F interactions to suppress non-radiative deactivation.

【 授权许可】

Unknown