Analytical Sciences

Substituted Position Effect on Twisted Intramolecular Charge Transfer of 1- and 2-Anthracene Aromatic Carboxamides as Chemosensors Based on Linear Polyether

Jeongsik KIM,* Tatsuya MOROZUMI,** Hisafumi HIRAGA,** and Hiroshi NAKAMURA**

*Division of Environmental Materials Science, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
**Section of Materials Science, Research Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan

Bi-chromophoric compounds linked to linear polyether N,N′-[oxybis(3-oxapentamethyleneoxy-2-phenyl)]-bis(1-anthracenecarboxamide) (1₄) and its analogues (1₅, 2₄ and 2₅) were synthesized. Their photochemical properties and complexation actions were investigated in acetonitrile. These fluoroionophores have shown weak emissions in the absence of guest ions, resulting in a twisted intramolecular charge transfer (TICT) quenching process (off state) of an anthracene aromatic amide moiety. After the formation of a complex with alkaline earth metal ions, a large enhancement of fluorescent intensities was obtained (on state). The efficiencies of controlling an off-on fluorescent signal using 1₄ and its analogues (1₅, 2₄ and 2₅) were larger than that of the 9-positioned analogue. These results suggested that the TICT relaxation process was effectively able to control using 1₄ and its analogues (1₅, 2₄ and 2₅) by complex formations.

J-STAGE: View this article in J-STAGE