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Z. Naturforsch. 2013, 68b, 445 – 452
doi:10.5560/ZNB.2013-3057
Coordination of N-Heterocyclic Carbene to H2SiX2 (X = Cl, OTf) and H3SiOTf (OTf = OSO2CF3): Synthesis of Donor-stabilized Parent Silylium Salts with Four- and Five-coordinate Silicon Atoms
Yun Xiong, Shenglai Yao and Matthias Driess
Institute of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 135, Sekr. C2, D-10623 Berlin, Germany
Reprint requests to Prof. Matthias Driess. E-mail: matthias.driess@tu-berlin.de
Received February 19, 2013 / published online Juli 2, 2013
Dedicated to Professor Heinrich Nöth on the occasion of his 85th birthday
The reactivity of the N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene towards dichlorosilane H2SiCl2, bis(trifluoromethanesulfonato)silane H2Si(OTf)2 (OTf = OSO2CF3), and silyl trifluoromethanesulfonate H3SiOTf has been investigated. It turned out that the coordination of the NHC ligand can occur stepwise to form the three neutral compounds (NHC)SiH2Cl2 (1), (NHC)2SiH2Cl2 (2), (NHC)SiH2(OTf)2 (3), as well as the two ion pairs [(NHC)SiH3]+(OTf) (4) and [(NHC)2SiH3]+(OTf) (5); the latter represent the first NHC adducts of the parent silylium cation (H3Si+). The multinuclear NMR and IR spectroscopic data of the products reflect the characteristics of four-, five-, and six-coordinate silane complexes. All new compounds were structurally characterized by single-crystal X-ray diffraction analyses.
Key words: Silicon, Silane Complexes, Hypercoordination, Main Group Elements
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