allyl-trimethyl-silane in tetrahydrofuran; diethyl ether under Ar: addn. of 157 mmol allyltrimethylsilane to a stirred suspension of 40.5 mmol WCl6 in diethyl ether at room temperature; stirring for 90 min; pptn.; filtration; cooling on an ice-bath; slow addn. of tetrahydrofuran with stirring;; warming to room temperature; crystallization; filtration after 90 min; washing with diethyl ether; drying under vac.; elem. anal.;;

THF in tetrahydrofuran; cyclohexane to WCl5 under N2 cyclohexane was added, mixt. was stirred, THF was added, mixt. was allowed to cool under N2 for 1 h; filtered, dried in vac., washed with cyclohexane and n-pentane;

tetrahydrofuran in tetrahydrofuran THF was added dropwise to solid W-compound and stirred at room temp. (N2 or Ar); concd., cooled (-25 °C, 3 days); crystn.; sepd., washed (diethyl ether); dried in vac.; elem.anal.;