Journal article
Ga3+ Incorporation into Al13 Keggin Polyoxometalates and the Formation of δ-(GaAl12)7+ and (Ga2.5Al28.5)19+ Polycations
Inorganic chemistry, Vol.59(15), pp.10461-10472
08/03/2020
DOI: 10.1021/acs.inorgchem.0c00743
Abstract
Keggin-type polyaluminum species (ϵ-Al13, δ-Al13, Al26, Al30, Al32) can form upon partial hydrolysis of Al3+-bearing solutions and are important species for water purification and contaminant transport. While the structural features for the major Al3+ polyaluminum species have been delineated, much less is known regarding heteroatom substitution and resultant structures other than the previously identified ϵ-GaAl127+ and ϵ-GeAl128+ cations. Single-atom substitution within polyaluminum species can change the surface reactivity within water treatment scenarios; thus, it is important to understand heteroatom incorporation within this system. The present work describes the synthesis and characterization of two novel Ga3+-substituted Keggin-type polyaluminum species. Na[GaO4Al12(OH)24(H2O)12](2,6-NDS)4(H2O)20.5 (δ-GaAl12) and [Ga2O8Al28.5Ga0.5(OH)58(H2O)27(SO4)2](SO4)4Cl7(H2O)8.5 (Ga2.5Al28.5) were crystallized from a thermally aged, partially hydrolyzed Ga3+/Al3+ solution. Structural refinement from single-crystal X-ray diffraction indicated fully occupied Ga3+ within tetrahedral site(s) of both isolated species. Partial substitution was observed for octahedral sites for the larger Ga2.5Al28.5 cluster. The chemical compositions of both clusters were confirmed by inductively coupled plasma mass spectrometry (ICP-MS). Density functional theory (DFT) calculations corroborated the structural refinement, with the energetics of Ga3+ substitution suggesting preferential substitution within tetrahedral sites for both species. Additional theoretical work suggests that the rotated trimer in δ-GaAl12 is highly reactive, which can serve as the driving force in the formation of the Ga2.5Al28.5 cluster.
Details
- Title: Subtitle
- Ga3+ Incorporation into Al13 Keggin Polyoxometalates and the Formation of δ-(GaAl12)7+ and (Ga2.5Al28.5)19+ Polycations
- Creators
- Mohammad Shohel - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesJennifer L Bjorklund - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesErik A Ovrom - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesSara E Mason - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United StatesTori Z Forbes - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.59(15), pp.10461-10472
- DOI
- 10.1021/acs.inorgchem.0c00743
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Language
- English
- Date published
- 08/03/2020
- Academic Unit
- Chemistry; Civil and Environmental Engineering; Core Research Facilities
- Record Identifier
- 9984216602602771
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