Derivate des Imidazols, XIII. Carben‐Komplexe des Siliciums und Zinns

Abstract

Imidazole Derivatives, XIII. – Carbene Complexes of Silicon and Tin Herrn Professor Peter Paetzold zum 60. Geburtstag gewidmet. Stable adducts of the composition L · SiCl 4 ( 2 ), L · SiR 2 Cl 2 ( 3,4 ), and L · SnR 2 Cl 2 ( 6 ) are formed by the reaction of the imidazol‐2‐ylidenes L ( 1 ) with the corresponding silicon and tin halides. For L = SiCl 4 ( 2b ; L = 1,3‐diethyl‐4,5‐dimethylimidazol‐2‐ylidene) and L · SnPh 2 Cl 2 ( 6c ; L = 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) the monomeric nature of the compounds containing pentacoordinated silicon and tin is established by X‐ray structure analyses. The reaction of 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene ( 1c ) with SnCl 2 leads to the formation of the monomeric stannylene complex L · SnCl 2 ( 7c ; L = 1,3‐diisopropyl‐4,5‐dimethylimidazol‐2‐ylidene) whose molecular geometry indicates a week carbon‐to‐tin donor bond [SnC(1) 2.290(5) Å].