Highly Selective Fluoride Ion Detection Based on a Fluorescent Alizarin-o-Aminomethylphenylboronic Acid Ensemble in Aqueous MeOH Solution
A self-organized fluorescent sensor consisting of alizarin and <I>o</I>-aminomethylphenylboronic acid <B>1</B> is presented, the ensemble shows highly selective fluoride ion-response in H<SUB>2</SUB>O–MeOH (1:4 w/w) at pH 5.5. Compound <B>1</B> (p<I>K</I><SUB>a</SUB> = 5.63) at pH 5.5 in the solution follows the equilibrium: alizarin–<B>1</B> + H<SUP>+</SUP> <B>1</B>H<SUP>+</SUP> + alizarin. Thus, F<SUP>−</SUP> added into the solution preferably binds to <B>1</B>H<SUP>+</SUP> to allow the ensemble to release alizarin, resulting in a fluorescence quenching.
- Chemistry letters
Chemistry letters 35(9), 996-997, 2006-09-05
The Chemical Society of Japan