in tetrahydrofuran Irradiation (UV/VIS); exclusion of air and moisture; Ar, Schlenk-technique; soln. of As-Mo-complex and Ni compd. in THF is irradiated at -10°C for 4 h; evapn. in vac., addn. of CH2Cl2, chromy. (-15°C, silica gel) with hexane/CH2Cl2 1. Cp2Ni, 2. Cp2Ni2(CO)2, 3. AsCp3Mo2Ni(CO)4, 4. Cp3Ni3(CO)2, 5. AsCp3Mo3(CO)6, with THF As2Cp6Mo4Ni2(CO)7; elem. anal.;

in toluene refluxing for 1.5 h; solvent and Fe(CO)5 removed in vac., residue dissolved in toluene; chromy. (silica gel) with hexane/toluene (1:1) yields Cp2Mo2(CO)6, then with toluene PhMe(MoCp(CO)2)2(AsMoCp(CO)3)Fe(CO)5 which is crystd. from CH2Cl2/hexane at -18°C; elem. anal.;