Lanthanide(III) complexes of bis-semicarbazone and bis-imine-substituted phenanthroline ligands: solid-state structures, photophysical properties, and anion sensing.
| Autor: | Nadella S; Analytical Science Division, Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat, India., Selvakumar PM, Suresh E, Subramanian PS, Albrecht M, Giese M, Fröhlich R |
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| Jazyk: | angličtina |
| Zdroj: | Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2012 Dec 21; Vol. 18 (52), pp. 16784-92. Date of Electronic Publication: 2012 Nov 13. |
| DOI: | 10.1002/chem.201201705 |
| Abstrakt: | Phenanthroline-based hexadentate ligands L(1) and L(2) bearing two achiral semicarbazone or two chiral imine moieties as well as the respective mononuclear complexes incorporating various lanthanide ions, such as La(III), Eu(III), Tb(III), Lu(III), and Y(III) metal ions, were synthesized, and the crystal structures of [ML(1)Cl(3)] (M=La(III), Eu(III), Tb(III), Lu(III), or Y(III)) complexes were determined. Solvent or water molecules act as coligands for the rare-earth metals in addition to halide anions. The big Ln(III) ion exhibits a coordination number (CN) of 10, whereas the corresponding Eu(III), Tb(III), Lu(III), and Y(III) centers with smaller ionic radii show CN=9. Complexes of L(2), namely [ML(2)Cl(3)] (M=Eu(III), Tb(III), Lu(III), or Y(III)) ions could also be prepared. Only the complex of Eu(III) showed red luminescence, whereas all the others were nonluminescent. The emission properties of the Eu derivative can be applied as a photophysical signal for sensing various anions. The addition of phosphate anions leads to a unique change in the luminescence behavior. As a case study, the quenching behavior of adenosine-5'-triphosphate (ATP) was investigated at physiological pH value in an aqueous solvent. A specificity of the sensor for ATP relative to adenosine-5'-diphosphate (ADP) and adenosine-5'-monophosphate (AMP) was found. (31)P NMR spectroscopic studies revealed the formation of a [EuL(2)(ATP)] coordination species. (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.) |
| Databáze: | MEDLINE |
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