in benzene bubbling of CO through a soln. of the Rh complex in C6H6 (4 h), evapn. of the final yellow sol. to a small vol. (vac.), addn. of n-hexane, pptn.; ''PrNH2 in the mother liquid;

in benzene byproducts: triphenylphosphine oxide; bubbling of O2 through C6H6 (15 min), addn. of the solid Rh complex, immediate forming of a brown soln., discontinuing of the O2 bubbling (1.5 h), closing the flask, cooling with ice (24 h), pptn. of a brickred compd.; filtration, washing (repeatedly with diethyl ether), drying (vac.); elem. anal.;