Novel Transition-Metal (M=Cr, Mo, W, Fe) Carbonyl Complexes with Bis(guanidinato)silicon(II) Ligands

• Published in: Chemistry : a European journal 2014-07, Vol.20 (31), p.9620-9626
• Main Authors: Mück, Felix M., Kloß, Dorit, Baus, Johannes A., Burschka, Christian, Tacke, Reinhold
• Format: Article
• Language: English
• Subjects: Carbonyl groups; Carbonyls; Chemistry; coordination chemistry; Crystal structure; guanidinato ligand; Ligands; Nuclear magnetic resonance; silicon; silylenes; Solid state; Spectroscopic analysis; Spectroscopy; transition-metal complexes
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201402889

The donor‐stabilized silylene 2 (the first bis(guanidinato)silicon(II) complex) reacts with the transition‐metal carbonyl complexes [M(CO)6] (M=Cr, Mo, W) to form the respective silylene complexes 7–10. In the reactions with [M(CO)6] (M=Cr, Mo, W), the bis(guanidinato)silicon(II) complex 2 behaves totally different compared with the analogous bis(amidinato)silicon(II) complex 1, which reacts with [M(CO)6] as a nucleophile to replace only one of the six carbonyl groups. In contrast, the reaction of 2 leads to the novel spirocyclic compounds 7–9 that contain a four‐membered SiN2C ring and a five‐membered MSiN2C ring with a MSi and MN bond (nucleophilic substitution of two carbonyl groups). Compounds 7–10 were characterized by elemental analyses (C, H, N), crystal structure analyses, and NMR spectroscopic studies in the solid state and in solution. The complexity of silicon: The donor‐stabilized silylene 1 (the first bis(guanidinato)silicon(II) complex) reacts with [M(CO)6] (M=Cr, Mo, W) and [Fe(CO)5] to form the respective transition‐metal silylene complexes 2–5. These compounds were characterized by elemental analyses (C, H, N), crystal structure analyses, and NMR spectroscopic studies in the solid state and in solution.