New amino acid ligated yttrium hydroxy clusters

Abstract

The synthesis of the four mixed pentanuclear yttrium hydroxy clusters [Y(5)(OH)(5)(alpha-AA)(4)(Ph(2)acac)(6)] (alpha-AA = D-phenyl glycine, L-proline, L-valine, and L-tryptophan; Ph(2)acac = dibenzoylmethanide) is reported. The solid state structures of all compounds were established by single crystal X-ray diffraction. In these enantiomerically pure chiral clusters the dibenzoylmethanide and amino acid ligands are accommodated in the coordination spheres of the yttrium atoms. The specific optical rotations of all four compounds were determined. PGSE NMR diffusion measurements as function of concentration have been carried out on one model cluster, proving these molecules to be prone to aggregation in chloroform solutions.

Characterization and Luminescence Properties of Lanthanide-Based Polynuclear Complexes Nanoaggregates

“…100 However, it is quite often used for the characterization of supramolecular complexes. Actually, there is a relationship between the diffusion coefficient D (m 2 s −1 ) and the molecular weight MW (g mol −1 ): 101…”

Rare‐Earth Metal Oxo/Hydroxo Clusters – Synthesis, Structures, and Applications

“…[21] As mentioned above, in our group we aimed to enhance the biological compatibility of our cluster compounds by functionalization of the clusters' ligand shells with amino acids to obtain the mixed dibenzoylmethanide and amino acid clusters [Ln 5 (OH) 5 (α-AA) 4 (Ph 2 acac) 6 ] (Ln = Y, Dy); see Figure 7. [69,75] The next step to enhancing the biocompatibility of our cluster compounds involved the synthesis of rare-earth metalbased clusters with luminescent properties for penetration of living cells. To achieve this goal, the anchoring of a cell-penetrating agent onto a rare-earth cluster core is necessary.…”

“…Inspired by earlier work by Zheng et al [25] it was shown that pentanuclear rare-earth clusters [Ln 5 (OH) 5 (α-AA) 4 (Ph 2 acac) 6 ] (Ln = Y, Dy) were obtained by treatment with dibenzoylmethane and the corresponding amino acid (α-AAH) in the presence of potassium tert-butoxide as base (Scheme 6). [69,75] As amino acids, 4 ]. [69] Hydrogen atoms and free solvent molecules are omitted for clarity.…”

“…[69,75] As amino acids, 4 ]. [69] Hydrogen atoms and free solvent molecules are omitted for clarity.…”

“…Moreover, the apical lanthanide atom lying on a twofold symmetry axis is coordinated by two of these η 2 -Ph 2 acac ligands. [69] Because [Ln 5 (OH) 5 (Ph 2 acac) 10 ] clusters are now accessible on a large scale, various investigations into their physical properties have been performed. These relate mainly to magnetism and luminescence and are discussed below.…”