Oxo-Nitrogenated Iron Complex, Catalytic System Comprising Said Oxo-Nitrogenated Iron Complex and Process for the (Co)Polymerization of Conjugated Dienes

Process for the preparation of a ligand having general formula (II):

• in which:
• R1 and R2, identical or different, represent a hydrogen atom;
• or they are selected from linear or branched, optionally halogenated, C1-C20, preferably C1-C15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups;
• R3 represents a hydrogen atom, or it is selected from linear or branched, optionally halogenated, C1-C20, preferably C1-C15, alkyl groups optionally substituted cycloalkyl groups, optionally substituted aryl groups;
• comprising reacting at least one primary amine having general formula (III);
• H2N—R3 (III)
• in which R3 has the above described meanings, with at least one compound having general formula (IV);
• in which R1 and R2 have the same meanings described above;
• in the presence of water, at a temperature ranging from 18° C. to 30° C., preferably at room temperature, for a time ranging from 1 hour to 10 days, preferably ranging from 1.5 hours to 8 days;
• said primary amine having general formula (III) and said compound having general formula (IV) being used in a molar ratio ranging from 1:10 to 1:2, preferably ranging from 1:5 to 1:1.5.