in benzene-d6 2 mol of the alkyne to 1 mol of the Ce complex, (N2 or Ar, room temp., ca. 8 h), formation of ((C5Me5)Ce(C2(t-Bu))2)n (>90 percent); (1)H NMR; not isolable (decompn. to a complex mixt. of organocerium compds. and 2,4-di-tert-butyl-1-butene-3-yne);
