in hexane under N2; addn. of the alkyne to soln. Mn-complex/hexane, soln. stirred(25°C, 20 h); evapn., residue dissolved in min. amt. CH2Cl2; sepn. of products by TL-chromy. (silica gel, hexane/CH2Cl2 (1/1)): 1. Mn2(CO)10, 2. unreacted Mn2(CO)9(MeCN), 3. Mn2(CO)8-complex; elem. anal.;