Crystal Structure and Absorption Spectroscopy of a Neodymium(III) Complex with Triethylenetetraaminehexaacetic Acid, Na₃[Nd(TTHA)]·2.5NaClO₄·7.617H₂O

Abstract

The crystal structure and absorption spectroscopy results of the Na(3)[Nd(TTHA)].2.5NaClO(4).7.617H(2)O compound are presented. The crystal structure of the complex was determined by X-ray analysis. Crystals are monoclinic, space group C2/c, with a = 38.446(8) Å, b = 10.552(2) Å, c = 25.796(5) Å, beta = 130.51(3) degrees, and Z = 4. The structure consists of monomeric (triethylenetetraaminehexaacetato)neodymate anions, perchlorate anions, sodium cations, and water molecules. The Nd(III) ion adopts a 10-coordinate geometry with six oxygen atoms and four nitrogen atoms from a ligand molecule, which is best described as a bicapped square antiprism. Absorption spectra of a single crystal were measured at room and liquid helium temperatures. Intensities of the f-f transitions were analyzed on the basis of Judd-Ofelt theory. The good correspondence between the spectra of [Nd(TTHA)](3)(-) in solution and in the single crystal suggests close similarity of both coordination polyhedra.

Structure and Dynamics of Lanthanide Complexes of Triethylenetetramine‐N,N,N′,N″,N′′′,N′′′‐hexaacetic Acid (H6ttha) and of Diamides H4ttha(NHR) Derived from H6ttha as Studied by NMR, NMRD, and EPR

“…We decided to neglect this contribution for the calculation of NdÀC distances, since, as [7]. In the crystals of the Nd complex [5], the ligand is coordinated to the metal ion in a decadentate fashion via the four N-atoms of the ethylenetriamine backbone and six carboxylate O-atoms, whereas the corresponding Dy 3 complex [7] has one of the acetate groups uncoordinated. Since the average distances of the three carboxylate resonances as determined from the relaxation rates are about the same and in good agreement with those in the crystal structure of [Nd(ttha)] 3À , it can be concluded that the solution-state structure of [Nd(ttha)] 3À is comparable to that in the solid state.…”

“…Because of its very small quadrupolar moment, 6 Li has a slow quadrupolar relaxation and, therefore, is a very Fig. 3 (5,15,25,37, and 458). The profiles show significant differences (see Fig.…”

Ten‐Coordinate Neodymium(III) Complexes with Triethylenetetraaminehexaacetic Acid

“…[5,17] This is different to the La III -TTHA system, where the 1 H and 13 C NMR spectra revealed the existence of only one coordination arrangement around the metal cation in solution. [5] Our results based on the optical properties of Nd III , [8,16] Eu III [17,18] and Ho III [13] complexes with TTHA revealed that species differing in the number of coordinated nitrogen and oxygen atoms, namely [Ln(N 4 3-, are present in the solution for the light and heavy lanthanide ions, respectively. Each of these species may form various stereoisomers, some of which may be op-tically active.…”

“…The absence of innersphere water molecules for Ln III -TTHA solutions at pH above 3 has been proved by emission spectroscopy [5,6] as well as NMR studies, [7] and was also confirmed in the crystal structures. [8][9][10][11][12][13][14][15][16] Previously, the coexistence of two distinct complexes of Eu III -TTHA in solution over the entire pH range has been reported. [5,17] This is different to the La III -TTHA system, where the 1 H and 13 C NMR spectra revealed the existence of only one coordination arrangement around the metal cation in solution.…”

Synthesis, Crystal Structures, and Properties of Oxovanadium(IV)–Lanthanide(III) Heteronuclear Complexes

“…To the best of our knowledge, the structure of the complexes formed by H 6 TTHA and lanthanide ions had not been studied by X-ray diffraction until 1997. [8] Heteronuclear complexes or coordination polymers formed with this ligand remain elusive. (TTHA)] 2À ions, which result in a one-dimensional chain.…”