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ABSTRACT: A series of lanthanide-doped nonanuclear yttrium(III) clusters with general formulas (Y 9-x Ln x)(acac) 16 (μ 3 -OH) 8 -(μ 4 -O)(μ 4 -OH) (Ln = Pr, Eu, Tb, Dy, and Yb) were synthesized. Characterization by single-crystal X-ray diffraction allowed for analysis of relative populations of yttrium (Z = 39) and dopant trivalent lanthanide (Z = 59-70) at every crystallographic metal position. Nonuniform distribution of ions along the three different sites seems to be correlated to the site volume and the ratio of ionic radii. In support, luminescence spectra of europium(III)-doped nonanuclear clusters were measured over a wide range of dopant concentrations. Emission intensities of peaks characteristic of specific sites correlate well with the site population determined through X-ray diffraction. Introduction Although a general approach to the fabrication of nanoen-tities in a precisely controlled manner is not yet available, it is widely accepted that coordination chemistry offers an attrac-tive approach to create sophisticated and single-sized nano-scale polynuclear clusters relevant to chemistry, physics, and biology. In this context and as part of our focus on the magnetism and optical properties of polynuclear metal com-plexes incorporating lanthanide ions, 1-3 we recently reinves-tigated the coordination chemistry of β-diketone ligands. We reported an interesting case of rational cluster nuclearity control that allowed the study of the optical properties of penta-, octa-, and nonanuclear europium(III) and terbium(III) clusters. 4 Our interest in lanthanide clusters comes from the well-established relevance of lanthanide ions and their partially filled 4f shell for both magnetism and optical properties. 5-7
Inorganic Chemistry 01/2010; 49:10970--10976. · 4.60 Impact Factor
