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Formation of Nanoscale [Ge 4 O 16 Al 48 (OH) 108 (H 2 O) 24 ] 20+ from Condensation of ϵ‐GeAl 12 8+ Keggin Polycations **
Author(s) -
Shohel Mohammad,
Bjorklund Jennifer L.,
Smith Jack A.,
Kravchuk Dmytro V.,
Mason Sara E.,
Forbes Tori Z.
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202017321
Subject(s) - crystallography , cluster (spacecraft) , deprotonation , isomerization , chemistry , condensation , single crystal , catalysis , physics , ion , biochemistry , organic chemistry , computer science , thermodynamics , programming language
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 (δ), but herein we report the isolation of largest Keggin‐type cluster that occurs through self‐condensation of four ϵ‐isomers ϵ‐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 ϵ‐isomer is the key for the formation of Ge 4 Al 48 because it activates deprotonation at key surface sites that control the self‐condensation process.