Next Article in Journal
Bioactivity In Vitro of Quercetin Glycoside Obtained in Beauveria bassiana Culture and Its Interaction with Liposome Membranes
Previous Article in Journal
Complete Chloroplast Genome of Pinus massoniana (Pinaceae): Gene Rearrangements, Loss of ndh Genes, and Short Inverted Repeats Contraction, Expansion
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessCommunication
Molecules 2017, 22(9), 1519;

Synthesis of Bisimidazole Derivatives for Selective Sensing of Fluoride Ion

School of Material Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China
Author to whom correspondence should be addressed.
Received: 10 August 2017 / Accepted: 9 September 2017 / Published: 11 September 2017
(This article belongs to the Section Photochemistry)
Full-Text   |   PDF [3524 KB, uploaded 11 September 2017]   |  


Rapid and efficient analysis of fluoride ion is crucial to providing key information for fluoride ion hazard assessment and pollution management. In this study, we synthesized one symmetrical structure called 1,4-bis(4,5-diphenyl-1H-imidazol-2-yl)benzene (1a) and two asymmetrical structures, namely 2-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-1H-phenanthro(9,10-d)imidazole (1b) and 2-(4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl)-1H-imidazo(4,5-f)(1,10)phenanthroline (1c), which served as an efficient anion sensor for fluoride ion over a wide range of other anions (Cl, Br, I, NO3, ClO4, HSO4, BF4, and PF6) owing to imidazole group in the main backbone. The absorption intensity of compound 1a at λmax 358 nm slightly decreased; however, a new band at λmax 414 nm appeared upon the addition of fluoride ion, while no evident change occurred upon the addition of eight other anions. The photoluminescence intensity of compound 1a at λmax 426 nm was nearly quenched and fluorescence emission spectra were broadened when fluoride ion was added into dimethyl sulfoxide (DMSO) solution of compound 1a. Compared with the optical behaviors of the DMSO solution of compound 1a in the presence of Bu4N+F, compounds 1b and 1c exhibited considerable sensitivity to fluoride ion due to the increase in coplanarity. Furthermore, compared with the fluorescence emission behaviors of the DMSO solutions of compounds 1a and 1b in the presence of Bu4N+F, compound 1c exhibited the most significant sensitivity to fluoride ion due to the charge transfer enhancement. Consequently, the detection limits of compounds 1a1c increased from 5.47 × 10−6 M to 4.21 × 10−6 M to 9.12 × 10−7 M. Furthermore, the largest red shift (75 nm) of the DMSO solution compound 1c in the presence of fluoride ion can be observed. Our results suggest that the increase in coplanarity and the introduction of electron-withdrawing groups to the imidazole backbone can improve the performance in detecting fluoride ion. View Full-Text
Keywords: imidazole; fluorescene; phenanthroline; fluoride ion; anion sensor imidazole; fluorescene; phenanthroline; fluoride ion; anion sensor

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Zhang, L.; Liu, F. Synthesis of Bisimidazole Derivatives for Selective Sensing of Fluoride Ion. Molecules 2017, 22, 1519.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top