Formation of Nanoscale [Ge₄O₁₆Al₄₈(OH)₁₀₈(H₂O)₂₄]²⁰⁺ from Condensation of ϵ‐GeAl₁₂⁸⁺ Keggin Polycations**

Abstract

Keggin-type polyaluminum cations belong to a unique class of compounds with their large positive charge, hydroxo bridges, and divergent isomerization/oligomerization. Previous reports indicated that oligomerization of this species can only occur through one isomer (d), but herein we report the isolation of largest Keggin-type cluster that occurs through selfcondensation of four e-isomers e-GeAl 12 8+ to form [Ge 4 O 16 Al 48 (OH) 108 (H 2 O) 24 ] 20+ cluster (Ge 4 Al 48). The cluster was crystallized and structurally characterized by single-crystal X-ray diffraction (SCXRD) and the elemental composition was confirmed by ICP-MS and SEM-EDS. Additional dynamic light scattering experiments confirms the presence of the Ge 4 Al 48 in thermally aged solutions. DFT calculations reveal that a single atom Ge substitution in tetrahedral site of eisomer is the key for the formation of Ge 4 Al 48 because it activates deprotonation at key surface sites that control the selfcondensation process.

The largest aluminum molecular rings: Phenol‐thermal synthesis, photoluminescence, and optical limiting

“…Compound AlOC‐92 possesses a ring diameter up to 4.0 nm, representing the largest single‐strand aluminum molecular ring. Although the ring nuclearity is still smaller than the large Al 48 Ge 4 clusters (2.4 nm) [ 39 ] , Al 32 aluminum oxo clusters (3.1 nm), [ 40 ] and Al 32 aluminum hydroxide molecules (2.2 nm), [ 41 ] the molecular size is exceeded (Figure S1). Notably, it is the first time that PyrC – with numerous aromatic rings was incorporated into cluster science.…”

Vanadium-substituted polycationic Al-oxo cluster in a porous ionic crystal exhibiting Lewis acidity

“…The hydrolysis and condensation of Al 3+ species in aqueous solutions have produced a series of polynuclear oxo-hydroxo Al clusters with various compositions, sizes, and shapes, [1][2][3][4] and offered potential applications including water treatment, dye removal, and catalysis. [5][6][7] A representative example of the oxohydroxo Al clusters is the Keggin-type [AlO 4 Al 12 (OH) 24 (H 2 O) 12 ] 7+ (Al 13 ) polycation: four Al 3 (OH) 6 (H 2 O) 3 trimers are connected to the central tetrahedral [AlO 4 ] site, and there are five rotational isomers (e, d, g, b, a), which form by the stepwise rotation of the trimers.…”