Synthesen und Kristallstrukturen der Lithierten Silylphosphane (CMe₃)₂SiFP(Mes)Li(THF)₃, (CMe₃)₂SiFLi(TMEDA)PMes und des Cyclischen Silylphosphanes [(CMe₃)₂SiPMes]₂

Abstract

Di-tert-butyldifluorsilne reacts with lithiated 2,4,6-trimethylphenylphosphane to give (CMe₃)₂SiFPHC₆H₂Me₃ (1). A lithium derivative is formed in the reaction of 1 with nC₄H₉Li. The crystal structures of the lithium derivatives (CMe₃)₂SiFP(C₆H₂Me₃)Li(THF)₃ (2) and (CMe₃)₂SiFLi(TMEDA)PC₆H₂Me₃(3) were determined. The phosphorus atom is planar in 2 and pyramidal in 3. A (SiPLiF)-four-membered ring is formed in 3. LiF-elimination leads to the formation of the (SiP)-four-membered ring (4). The ring system of 4 is completely asymmetrical, indicating that the sterical limits of the dimerisation of the intermediate silaphosphene have been reached. Both 2 and 3 react with CMe₃SiF₃ to give the substituted compound (CMe₃)₂SiFP(SiF₂CMe₃)C₆H₂ Me₃ (5).