in toluene N2-atmosphere; stirring (80°C, 1 h); addn. of CH2Cl2, filtration, cooling (-100°C), decantation from Fe3(CO)12, concn. (vac.), chromy. (-25°C, SiO2, CH2Cl2, then CH2Cl2/THF), concn., crystn. (CH2Cl2/toluene, -30°C); elem. anal.;