Metallocene compounds and use thereof in catalysts for the polymerization of olefins

A metallocene compound of formula (I)

• (YRp)q(Cp)(Cp′)MX2 (I)
• wherein Cp is a group selected from those of formula (II) and (III):
• wherein m and n, same or different from each other are integers from 2 to 6;
• Cp′ is a group selected from those of formula (II), (III)
• wherein (YRp)q is a divalent group which bridges the two groups Cp and Cp′, Y being selected indifferently from C, Si, Ge, N and P;
• p is 1 when Y is N or P, and is 2 when Y is C, Si or Ge;
• q is 0, 1, 2 or 3;
• M is a transition metal selected from Ti, Zr or Hf;
• the substituents X, same or different from each other, are halogen atoms, —OH, —SH, R, —OR, —SR, —NR2 or —PR2;
• the substituents R, same or different from each other, are hydrogen atoms, C1-C20 alkyl radicals, C3-C20 cycloalkyl radicals, C2-C20 alkenyl radicals, C6-C20 aryl radicals, C7-C20 alkylaryl radicals or C7-C20 arylalkyl radicals, optionally containing Si or Ge atoms and, additionally, two adjacent R substituents on Cp or Cp′ may form a C5-C8 cycle and, further, two R substituents of the same YR2 group or of two adjacent YR2 groups may form a ring comprising from 3 to 8 atoms;
• when q=0, the R′ substituents are defined as the R substituents while, when q=1,2, or 3, the R′ substitutents on the on the Cp and Cp′ groups are replaced by the divalent group (YRp)q which bridges the two groups Cp and Cp′, with the proviso that when Cp and Cp′ are octahydrofluorenyl groups, q is different from 0.