Lanthanide(III) Complexes of Bis-semicarbazone and Bis-imine-Substituted Phenanthroline Ligands: Solid-State Structures, Photophysical Properties, and Anion Sensing

作者：Nadella Sandeep; Selvakumar Paulraj M; Suresh Eringathodi; Subramanian Palani S^*; Albrecht Markus; Giese Michael; Froehlich Roland

来源：Chemistry - A European Journal, 2012, 18(52): 16784-16792.

DOI：10.1002/chem.201201705

• chirality
• crystal structures
• lanthanides
• phosphate ions
• sensors

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 [(MLCl3)-Cl-1] (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 LnIII 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 [(MLCl3)-Cl-2] (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%26apos;-triphosphate (ATP) was investigated at physiological pH value in an aqueous solvent. A specificity of the sensor for ATP relative to adenosine-5%26apos;-diphosphate (ADP) and adenosine-5%26apos;-monophosphate (AMP) was found. P-31 NMR spectroscopic studies revealed the formation of a [EuL2(ATP)] coordination species.

• 出版日期2012-12
• 单位海洋化工研究院有限公司