Reaction of Molybdenocene and Tungstenocene Derivatives with the Divalent Silicon Species SiN^tBuCHCHN^tBu and (C₅Me₅)₂Si

Abstract

The divalent organosilicon compounds (C5Me5)2Si (Cp*2Si) and (SiLN2) have been compared concerning their reactivity toward metallocene derivatives of molybdenum and tungsten. While Cp*2Si does not react with Cp2MH2 (M = Mo, W), either thermally or photochemically, the reaction of SiLN2 with Cp2MH2 leads via silanediyl insertion to Cp2M(H)(SiLN2H) (M = Mo (1a), W (1b)). Irradiation of a mixture of Cp2Mo(PEt3) and Cp*2Si yields only decomposition products, whereas photolysis of equimolar amounts of Cp2Mo(PEt3) and SiLN2 results in the formation of the silanediyl complex Cp2Mo(SiLN2) (2). 2 is extremely moisture sensitive and easily adds one molecule of water to yield the metallosilanol Cp2Mo(H)(SiLN2OH) (3). 1a and 2 have been characterized by X-ray crystallography. 2 is the first molybdenum silanediyl complex with a tricoordinated silicon atom. The silicon−molybdenum interaction in 2 has to be described as a dative bond from the silicon to the metal atom.