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

Research output: Contribution to journalArticle


  • Lorenz J. Schiegerl
  • Antti Karttunen

  • Jan Tillmann
  • Sebastian Geier
  • Gabriele Raudaschl-Sieber
  • Markus Waibel
  • Thomas F. Fässler

Research units

  • Technical University of Munich
  • Wacker Chemie AG


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.


Original languageEnglish
Pages (from-to)12950-12955
Number of pages6
JournalAngewandte Chemie - International Edition
Issue number39
Publication statusPublished - 24 Sep 2018
MoE publication typeA1 Journal article-refereed

    Research areas

  • cluster compounds, isotope enrichment, NMR spectroscopy, quantum chemical calculations, silicon

Download statistics

No data available

ID: 29203971