New halogenated bis(cyclopentadienyl) compounds of the general formula ##STR1## in which X represents a halogen atom having an atomic number of at most 35, that is to say a fluorine, bromine or preferably chlorine atom, R.sub.1 and R.sub.1 ' each represents a hydrogen atom or a methyl group, and n = 1, 2, 3 or 4. The monomer of the formula (I) undergoes spontaneous dimerization or oligomerization respectively after it is formed. The oligomer has the formula ##STR2## WHERE P IS 2 TO 20.
新的卤代双(
环戊二烯基)化合物,其一般式为##STR1## 其中X代表原子序数最多为35的卤素原子,即
氟、
溴或优选的
氯原子,R.sub.1和R.sub.1 '分别代表氢原子或甲基基团,n = 1、2、3或4。式(I)的单体在形成后会自发二聚或寡聚。寡聚物的式子为##STR2## 其中P为2至20。