Synthesis, Characterization, and Use of Lanthanide Chelate of β-Diketonate Based Ligand as a Luminescent Biolabel

Abstract

In this study, we aimed to synthesize a β-diketonate-based ligand and its Eu(III) complex which are used for luminescent biolabel. For this purpose, we chose acetophenone as the starting material which contains methyl group at the alpha position of the ketone group. Firstly, we obtained 4,4,5,5,6,6,7,7-octafluoro-3,8-dihydroxy-1,10-diphenyldeca-2,8-diene-1,10-dione (H2ODIT) ligand in a reaction between acetophenone and diethyloctafluoroadipate with Claisen condensation. This ligand was characterized by 1H-NMR, 13C-NMR, and mass spectral analyses. We obtained a single crystal H2ODIT as characterized by X-ray analysis. At the second step, in order to bind H2ODIT to the antibody, it is reacted with chlorosulfonic acid. As a result of this reaction, the functional group of -ClSO2 was bound to the structure. The structure of H2CODIT was characterized by NMR and mass spectral analysis. In the third step, to understand the usability of the ligand as a biolabel, the complex compound was synthesized with EuCl3. The complex compound was excited with UV light at 306 nm wavelength, specific hypersensitive 5D0 → 7F2 phosphorescence electronic transition of the Eu(III) was observed which proved that the luminescent H2CODIT molecule can work as a biolabel.

Keywords

• Beta-diketonate
• Claisen condensation
• Europium(III) complex
• Keto-enol tautomerism
• Luminescence
• Biolabel

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