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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
Author(s) -
Schiegerl Lorenz J.,
Karttunen Antti J.,
Tillmann Jan,
Geier Sebastian,
RaudaschlSieber Gabriele,
Waibel Markus,
Fässler Thomas F.
Publication year - 2018
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201804756
Subject(s) - chemistry , analytical chemistry (journal) , raman spectroscopy , silicon , nmr spectra database , mass spectrometry , nuclear magnetic resonance spectroscopy , electrospray ionization , spectroscopy , crystallography , spectral line , stereochemistry , physics , organic chemistry , chromatography , quantum mechanics , astronomy , optics
Polyanionic silicon clusters are provided by the Zintl phases K 4 Si 4 , comprising [Si 4 ] 4− units, and K 12 Si 17 , consisting of [Si 4 ] 4− and [Si 9 ] 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 29 Si isotope‐enriched samples. 29 Si‐MAS NMR and Raman shifts of the phase‐pure solids K 4 Si 4 and K 12 Si 17 were interpreted by quantum‐chemical calculations. Extraction of [Si 9 ] 4− clusters from K 12 Si 17 with liquid ammonia/222crypt and their transfer to pyridine yields in a red solid containing Si 9 clusters. This compound was characterized by elemental and EDX analyses and 29 Si‐MAS NMR and Raman spectroscopy. Charged Si 9 clusters were detected by 29 Si NMR in solution. 29 Si and 1 H NMR spectra reveal the presence of the [H 2 Si 9 ] 2− cluster anion in solution.