Related Experiment Video
Updated: Aug 7, 2026
07:07
Synthetic Methodology for Asymmetric Ferrocene Derived Bio-conjugate Systems via Solid Phase Resin-based Methodology
Published on: March 12, 2015
Bis-azamacrocyclic anthracene as a fluorescent chemosensor for cations in aqueous solution
Yasuhiro Shiraishi1, Yoshiko Kohno, Takayuki Hirai
1Research Center for Solar Energy Chemistry, and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan. shiraish@cheng.es.osaka-u.ac.jp
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
A new fluorescent chemosensor, bis-azamacrocyclic anthracene (L2), detects pH and metal cations. It shows distinct responses to zinc and cadmium ions, highlighting its potential for aqueous solution analysis.
Area of Science:
- Supramolecular Chemistry
- Analytical Chemistry
- Materials Science
Background:
- Development of novel fluorescent chemosensors is crucial for detecting analytes in aqueous environments.
- Macrocyclic compounds like cyclen offer unique binding properties for metal ions.
- Anthracene derivatives are known for their fluorescent characteristics.
Purpose of the Study:
- To synthesize and characterize a novel bis-azamacrocyclic anthracene (L2) as a fluorescent chemosensor.
- To investigate the pH-dependent fluorescence response of L2.
- To evaluate the selectivity and sensitivity of L2 towards metal cations (Zn2+ and Cd2+) in aqueous solution.
Main Methods:
- Synthesis of bis-azamacrocyclic anthracene (L2) and monoazamacrocyclic anthracene (L1).
- Fluorescence spectroscopy to study the response of L2 to pH variations.
- Potentiometric titration to determine protonation states.
- Fluorescence titration to assess metal cation binding and response.
Main Results:
- L2 exhibits a sigmoidal pH response with a pKa of 7.4, lower than L1 (pKa 8.3), due to the protonation of both cyclen rings.
- L2 shows selective fluorescence enhancement for Zn2+ (2:1 response) and Cd2+ (1:1 response) at basic pH.
- At neutral pH, L2 displays a Zn2+-induced fluorescence increase (2:1 response), unlike L1 which shows fluorescence quenching.
Conclusions:
- Bis-azamacrocyclic anthracene (L2) functions as an effective fluorescent chemosensor for pH and specific metal cations.
- The dual cyclen structure in L2 provides distinct binding and signaling capabilities compared to mono-cyclen derivatives.
- L2 demonstrates significant potential for real-time monitoring of cations in aqueous solutions.
