Synthesis, Structures, and Fluorescence Properties of Dimeric Aluminum Oxo Clusters

Abstract

Aluminum is an important component for luminescence. However, the fluorescent aluminum complex with unambiguous structural information is still limited. Herein, we report a series of fluorescence aluminum oxo clusters (AlOCs). By introducing an additional coordination site to the aromatic conjugation ligand, cluster nuclearity increment and fluorescence variation are observed. Al8(OH)2(μ4-O)2(1-NA)2(OEt)16 (AlOC-41, 1-NA = 1-naphthoic acid, OEt = ethanol) is made up of two tetrahedral subunits. By introducing an additional coordination site to the aromatic conjugation ligand, we isolate a high nuclearity compound Al10(μ3-O)2(3-HNA)2(OEt)22 (AlOC-47, 3-HNA = 3-hydroxy-2-naphthoic acid). Correspondingly, their luminescence performance is different (blue fluorescence in AlOC-41 and green in AlOC-47). Present herein is a platform to illustrate the relationship between synthesis, structure, and fluorescence properties.

Two solvent-dependent Al16 nanorings: design, synthesis and nonlinear optical limiting behavior

“…The comparative emission spectra show that the luminescence of the nanoring can be attributed to the coordination of the 2-NA ligand with inorganic aluminum atoms. 46 The difference in their emission intensity may be related to the quantity of the 2-NA ligands (24 in AlOC-134 vs. 20 in AlOC-135 ) (Fig. 3d).…”

Supramolecular Chemistry of Windmill-like Al10 Clusters: Adjustable Guests and Hydrogen-Bonding Networks for Enhanced Optical Limiting

“…The solvent choice is also a consideration. Since we had previously obtained a non-windmill-like cluster ( AlOC-45 ) using ethanol, we took the more sterically hindered benzyl alcohol here. The auxiliary solvent can be acetonitrile or 1,4-dioxane.…”

Self-Assembly of Lanthanide–Aluminum Cluster-Organic Frameworks with Magnetocaloric Effect and Luminescence

“…So far, Eu III has found widespread usage in sensing applications because of its robust emission of visible light, particularly in the red region; Al III is also a suitable material for plasmonic antennas as its high luminescence efficiency. ,, Therefore, the introduction of Al III ions into the lanthanide metal–organic frameworks may enhance the photoluminescence efficiency. Figure illustrates the luminescent behavior of Eu 6 Al at an ambient temperature.…”

“…In recent decades, substantial theoretical and experimental endeavors have been focused on the chemistry of metal–organic frameworks (MOF) due to their captivating structural multiformities and excellent properties. − And, metal–organic frameworks based on lanthanide-transition (4f–3d) ions exhibit extraordinary physical as well as chemical properties, particularly in magnetism and photoluminescence. − As a result, a large amount of MOFs based on 4f–3d ions have been further explored, for instance, [Ln–Cu], [Ln–Cr], [Ln–Co], [Ln–Ni], and [Ln–Mn]. ,− In comparison with the well-developed cluster chemistry of metal–organic frameworks based on 4f–3d ions, the chemistry of MOFs based on 4f–3p ions has not been fully explored so far. Aluminum is the most adequate metal in the earth’s crust and is extensively employed in printing fabric, water treatment, catalysis, and optics. − It is reported that aluminum also possesses the ability of high luminescence efficiency, making it a suitable material for plasma antennas . The investigation of the mechanism in the improvement of luminescence efficiency by Al III ions has never ceased .…”