carbon monoxide; ethylaluminum dichloride; triphenylphosphine in benzene a vigorously stirred suspn. of Mo-complex in benzene was treated with 5equiv of EtAlCl2 in benzene under CO atmosphere for 1 h, a benzene soln. of PPh3 was added, mixt. was stirred for addnl. 30 min; reaction was monitored by IR spectroscopy; solvent was evapd. in vacuo at 50°C, residue dissolved in CH2Cl2, detailed isolation of the product is described in the paper by K. Seyferth, R. Taube, L. Bencze and L. Marko, J. Organomet. Chem., 137 (1977) 275; identified by IR spectrum;