in toluene 1 equiv. CF3COOD was added slowly to stirred soln. CpMo(η4-2,3-dimethylbuta-1,3-diene)Me2 in toluene and stirred for 1 h; solvent was removed in vacuo, residue was recrystd. from pentane at -80°C; elem. anal.;

in toluene 2 equiv. CF3COOD was added slowly to stirred soln. CpMo(η4-2,3-dimethylbuta-1,3-diene)Me2 in toluene and stirred for 1 h; solvent was removed in vacuo, residue was wasjed with pentane; elem. anal.;