in benzene byproducts: Ph2PPPh2; PPh2Cl injected into Hf complex soln. in C6H6, stirred for 3 min at room temp.; solvent removed, solid extd. with n-hexane to leave Hf(cp)2Cl2;

in benzene byproducts: P(C6H5)2As(C6H5)2; AsPh2Cl injected into Hf complex soln. in C6H6, stirred for 3 min at room temp.; solvent removed, solid extd. with n-hexane to leave Hf(cp)2Cl2;