Selective Probing of Potassium Ion in Solution by Intramolecular Excimer Fluorescence of Dibenzo-Crown Ethers

Kida Motoki

Kubo Mayuko

Ujihira Tomoyuki

Ebata Takayuki

Abe Manabu

Inokuchi Yoshiya

ChemPhysChem

Observation of an excimer fluorescence in solution is proposed for detecting the encapsulation of potassium ion as opposed to other alkali ions by dibenzo-crown ethers. The scheme has been validated by ultraviolet photodissociation (UVPD) spectroscopy of dibenzo-21-crown-7 and dibenzo-24-crown-8 complexes with potassium ion, K+·DB21C7 and K+·DB24C8, performed under cold (~10 K) conditions in the gas phase and by quantum chemical calculations of the geometry and electronic structures of the complexes. Calculations suggest formation of a closely spaced excimer structure of benzene rings only for the K+·DB24C8. Interaction of the rings may lead to lifetime broadening in UV absorption, which is experimentally observed in the gas phase, indeed, only for this cold complex. Consistently, intramolecular excimer fluorescence of DB24C8 in solution is observed only for K+·DB24C8. The excimer fluorescence is not observed with other alkali metal ions. The detection of such intramolecular excimer fluorescence therefore can, potentially, serve as a simple, background-fee, selective probe of potassium ion in solution.

crown ethers

fluorescence

photodissociation spectroscopy

metal ions

excimer

Chemistry [ 430 ]

eng

Wiley-VCH

Copyright (c) 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This is the accepted version of the following article: [M. Kida, M. Kubo, T. Ujihira, T. Ebata, M. Abe, and Y. Inokuchi.(2018), Selective Probing of Potassium Ion in Solution by Intramolecular Excimer Fluorescence of Dibenzo-Crown Ethers. ChemPhysChem, 19: 1–6], which has been published in final form at http://doi.org/10.1002/cphc.201800163. This article may be used for non-commercial purposes in accordance with Wiley Self-Archiving Policy.

This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。

[ISSN] 1439-4235

[ISSN] 1439-7641

[DOI] 10.1002/cphc.201800163

[PMID] 29542235