Anion Binding-Induced White Light Emission using a Water-Tolerant Fluorescent Molecular Tweezer

作者：Kumar Rajesh; Srivastava Aasheesh

来源：Chemistry - A European Journal, 2016, 22(10): 3224-+.

DOI：10.1002/chem.201504269

<jats:title>Abstract</jats:title><jats:p>A novel fluorescent molecular tweezer (FMT), built on the pyridine‐2,6‐bis‐carboxamide framework, has been developed that, in presence of a red emitter, gives rise to white light emission in response to the addition of H<jats:sub>2</jats:sub>PO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> anions. The FMT incorporates two pyrene moieties as fluorescent reporter units and a strategically placed amine residue that imparts pH sensitivity to the fluorescence and offers additional electrostatic/hydrogen‐bonding interactions to the anions. As a result, this FMT selectively binds monoanionic tetrahedral oxyanions such as H<jats:sub>2</jats:sub>PO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> and HSO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> that contain hydrogen bond donors and acceptors, and can sense their presence in aqueous acetonitrile through changes in fluorescence. Anion binding results in excimer formation by the pyrenes and a bluish‐green emission from the FMT. Both amide and amine residues of the FMT interact with these anions. The binding stoichiometry with H<jats:sub>2</jats:sub>PO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> and HSO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> was found to be 1:1 and affinity of the FMT for these anions is of the order of 10<jats:sup>4</jats:sup> <jats:sc>m</jats:sc><jats:sup>−1</jats:sup>. The limit of detection for H<jats:sub>2</jats:sub>PO<jats:sub>4</jats:sub><jats:sup>−</jats:sup> was found to be 13 n<jats:sc>m</jats:sc>. Addition of a perylene monoimide‐based red emitter gives rise to panchromatic emission perceived as white light.</jats:p>

• 出版日期2016-3-1