Refine your search:     
Report No.

Optical properties of trinuclear citrate complexes containing 4f and 5f block metals

Aoyagi, Noboru  ; Palladino, G.*; Nagasaki, Shinya*; Kimura, Takaumi 

The speciation and coordination geometries of M(III)-citrate complexes in aqueous solutions, where M denotes Eu, Tb, Lu, or Cm, are studied using potentiometric titration, nuclear magnetic resonance spectroscopies. Their photophysical properties are also characterized by time-resolved fluorescence spectra. The formation constants of mononuclear, dinuclear, and trinuclear Lu-citrate species were determined by potentiometric titration in 3.00 M NaClO$$_{4}$$ aqueous media. Terminal carboxylic conformation in trinuclear complexes comprised both the five- and six-membered rings at different exchanging rates. Hydration states evaluated for Eu$$^{3+}$$ ions are the chemical formula of [Eu(Cit)$$_{2}$$ (H$$_{2}$$ O)$$_{2.5}$$ ]$$^{3-}$$ and [Eu$$_{3}$$(OH)$$_{4}$$(Cit)$$_{4}$$(H$$_{2}$$O)$$_{3.4}$$]$$^{7-}$$. These complexes in aqueous solution have geometrical similarity to the crystal structures in the literature. Furthermore, the entity of the hetero-trinuclear complex induces the intramolecular energy transfer from Tb$$^{3+}$$ to Eu$$^{3+}$$. The incorporation of Cm$$^{3+}$$ into these homo/hetero-trinuclear citrate complexes proved to be a successful trial to probe the formation of actinide polymer at a trace level.



- Accesses




Category:Chemistry, Multidisciplinary



[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.