Charged Si9 Clusters in Neat Solids and the Detection of [H2Si9]2− in Solution: A Combined NMR, Raman, Mass Spectrometric, and Quantum Chemical Investigation

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2018-09-24
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Mcode
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Language
en
Pages
6
12950-12955
Series
Angewandte Chemie - International Edition, Volume 57, issue 39
Abstract
Polyanionic silicon clusters are provided by the Zintl phases K4Si4, comprising [Si4]4− units, and K12Si17, consisting of [Si4]4− and [Si9]4− clusters. A combination of solid-state MAS-NMR, solution NMR, and Raman spectroscopy, electrospray ionization mass spectrometry, and quantum-chemical investigations was used to investigate four- and nine-atomic silicon Zintl clusters in neat solids and solution. The results were compared to 29Si isotope-enriched samples. 29Si-MAS NMR and Raman shifts of the phase-pure solids K4Si4 and K12Si17 were interpreted by quantum-chemical calculations. Extraction of [Si9]4− clusters from K12Si17 with liquid ammonia/222crypt and their transfer to pyridine yields in a red solid containing Si9 clusters. This compound was characterized by elemental and EDX analyses and 29Si-MAS NMR and Raman spectroscopy. Charged Si9 clusters were detected by 29Si NMR in solution. 29Si and 1H NMR spectra reveal the presence of the [H2Si9]2− cluster anion in solution.
Description
Keywords
cluster compounds, isotope enrichment, NMR spectroscopy, quantum chemical calculations, silicon
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Citation
Schiegerl, L J, Karttunen, A J, Tillmann, J, Geier, S, Raudaschl-Sieber, G, Waibel, M & Fässler, T F 2018, ' Charged Si 9 Clusters in Neat Solids and the Detection of [H 2 Si 9 ] 2− in Solution : A Combined NMR, Raman, Mass Spectrometric, and Quantum Chemical Investigation ', Angewandte Chemie - International Edition, vol. 57, no. 39, pp. 12950-12955 . https://doi.org/10.1002/anie.201804756