Electron Donor Composition For A Solid Catalyst, Solid Catalyst Composition Used In The Polymerisation Of A-Olefins, And Process For The Production Of A Polymer Consisting Of A-Olefin Units Using The Solid Catalyst Composition

An electron donor composition comprising:

• (A) at least one compound represented by the following formula (I):
• and
• (B) at least one compound represented by formula (II):
• wherein R1, R2, R3, R4, R5, R6, R7 and R8 have either the same or different meanings selected from hydrogen, halogen, linear or branched C1-20-alkyl, C6-20-aryl, C7-20-aralkyl, 4- to 7-membered cyclyl;
• R9 and R10 may either have the same or different meanings selected from linear or branched C1-20-alkyl, C6-20-aryl, C7-20-aralkyl, 4- to 7-membered cyclyl;
• and R11 and R12 have either the same or different meanings selected from C1-10-alkyl, 4- to 7-membered cyclyl, C6-20-alkyl and C7-20-aralkyl.