Spectroscopic Characterization of Eu(III) Complexes with New Monophosphorus Acid Derivatives of H4dota

Abstract

The luminescence lifetimes of europium(III) complexes with new monophosphorus acid derivatives of H(4)dota were measured by means of time-resolved laser-induced luminescence spectroscopy in H(2)O and D(2)O. The hydration numbers of these complexes were estimated using different empirical equations [Horrocks and Sudnick (1979) J. Am. Chem. Soc. 101 (1979) 334; Choppin and Barthelemy(1989) Inorg. Chem. 28, 3354-3357; Choppin and Bünzli Lanthanide probes in life, chemical and earth sciences. Theory and practice (1989); Kimura and Kato J. Alloys Comp. 275-277 (1998) 806; Parker (1999) J. Chem. Soc., Perkin Trans. 2, 493-503; Supkowski and Horroks (2002) Inorg. Chim. Acta. 340, 44-48]. It was shown that all the relationships gave similar results with a satisfactory precision. The hydration numbers of complexes of H(3)do3a and H(4)dota agreed with the literature values. One water molecule is coordinated in complexes of the new ligands. The results showed that the Choppin formula based on measurements only in H(2)O can be satisfactorily used for estimation of the hydration numbers.

Lanthanide(III) Complexes of 4,10‐Bis(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecane‐1,7‐diacetic acid (trans‐H6do2a2p) in Solution and in the Solid State: Structural Studies Along the Series

“…Above this pH, the reaction is too fast to be followed by the available techniques, as the intermediate is quickly rearranged to the final product (q < 1, Table S4). However, the reaction mechanism is the same over the pH range 4-6 as the luminescence spectra ( Figure S5) of the reaction intermediate, {Eu- [ [51][52][53] The luminescence decay time (t = 0.794 ms) of the Eu III -H 6 L complex in water leads to q = 0.6 AE 0.5, estimated according to Choppins formula.…”

Dissociation kinetics study of Ce(III) complexes with H8dotp (H8dotp = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis (methylphosphonic acid))

“…The donor atoms are aligned in a twisted square antiprismatic (TSA) arrangement. The luminescence measurements done on [Eu(dotp)] 5− complex in solution as well as in the frozen state at temperature 77 K [14,15] confirm that no water molecule is directly bound in the first coordination sphere.…”

Lanthanide(III) Complexes of 2‐[4,7,10‐Tris(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecan‐1‐yl]acetic Acid (H7DOA3P): Multinuclear‐NMR and Kinetic Studies

“…The experimental methodology for the TRFLS experiments and their application in kinetic studies were described in [14] [31]. The precision for the coordinated H 2 O molecules determined was estimated as AE 0.5, based on published data [29], and refs. cit.…”

“…The reaction was started after addition of perchloric acid (c(H þ ) ¼ 3 mol dm À3 ) and the average number of coordinated H 2 O molecules to the Eu III was determined as described in [14] [29]. The Eu III complex with the title ligand contains probably no H 2 O molecule (t ¼ 0.95 -1.12 ms for Eu III complex measured in equilibrium at pH 6 -7), and the structure of the kinetic intermediate formed must be similar, as indicated by luminescence spectroscopy (Fig.…”