Intense Near‐IR Emission from Nanoscale Lanthanoid Fluoride Clusters

Abstract

Fluoride clusters of lanthanoids can be prepared in organic solvents by metathetical reactions of Ln(SePh)3 with NH4F. The first products of these reactions, [(py)24Ln28F68(SePh)16] (Ln=Pr, Nd; py=pyridine; see structure), are currently the largest discrete lanthanoid clusters ever isolated. Emission experiments on the neodymium compound reveal a near‐IR quantum efficiency of 41 %.

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

“…[65] Three years later, Hendrickson et al reported on the isolation of an unexpected tetranuclear terbium compound with pyridinoacetate as supporting ligand. [66] Through the use of a modified diketonate with redox-active ferrocenyl substituents on the backbone of the ligand, tetranuclear hydroxo clusters [Ln 4 -(μ 4 -OH) 4 (FcacacPh) 8 ] (with Ln = Yb, Lu; FcacacPh = benzoylferrocenoylmethanide) were obtained in our group (Figure 3). [33] These compounds each feature eight ferrocenyl groups an-chored onto the cubane-like [Ln 4 (μ 4 -OH) 4 ] 8+ unit through bridging/chelating diketonate ligands.…”

“…[3,33] Figure 3. Solid-state structure of [Ln 4 (μ 4 -OH) 4 (FcacacPh) 8 ]. Hydrogen atoms are omitted for clarity.…”

“…[3] As well as the cluster compounds from our group, a tetradecanuclear cluster core can also be stabilized with acetylacetonate. [39] Fang and Li synthesized the [Ln 14 (μ 4 -OH) 2 (μ 3 -OH) 16 (μ-η 2 -acac) 8 (η 2 -acac) 16 ] clusters (with Ln = Tb, Dy) by hydrolyzing Ln(acac) 3 ·4 H 2 O (Ln = Tb, Eu) in CH 2 Cl 2 /hexane with 2,2′-dipyridyl sufide as base. [40] The second completely hydrolytic approach involves the deprotonation of water molecules in the starting material in a controlled manner.…”

“…[6] In addition, their optical properties have been exploited for use in luminescent materials. [7][8][9] Furthermore, rare-earth metal clusters have been applied in catalytic processes or as precursors for lanthanide-based oxide materials. [10,11] The term "cluster" was originally used for the description of compounds containing several metals connected by metal-to-metal bonds.…”

Synthesis and characterization of decanuclear Ln(III) cluster of mixed calix[8]arene-phosphonate ligands (Ln=Pr, Nd)

“…The design and construction of high-nuclearity lanthanide (Ln) clusters is one of the most active research frontiers in coordination chemistry, not only due to their aesthetically pleasing structures [1] but also their potential applications including luminescence [2], magnetism [3], catalyst [4] and so on [5]. In recent years, chemists have paid much more attention on constructing polymetallic complexes by using calixarenes [6].…”