Iron complexes and their use in polymerization processes

Iron complex (A) of formula (Ib):

• wherein the variables have the following meaning
• R1A-R2A independently of one another denote hydrogen, C1-C20-alkyl, C2-C20-alkenyl, C6-C20-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, or SiR113, wherein the organic radicals R1A-R2A can also be substituted by halogens, and/or two radicals R1A-R2A can also be bonded with one another to form a five-or six-membered ring,
• R3A-R5A, R8A and R10A independently of one another denote hydrogen, C1-C22-alkyl, C2-C22-alkenyl, C6-C22-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, NR12A2, OR12A, halogen, SiR11A3 or five-, six- or seven-membered heterocyclyl, which comprises at least one atom selected from the group consisting of N, P, O or S, wherein the organic radicals R3A-R10A can also be substituted by halogens, NR12A2, OR12A or SiR11A3 and/or in each case two radicals R3A-R5A and/or in each case two radicals R6A-R10A can also be bonded with one another to form a five-, six-or seven-membered ring and/or in each case two radicals R3A-R5A and/or in each case two radicals R6A-R10A are bonded with one another to form a five-, six-or seven-membered heterocyclyl, which comprises at least one atom selected from the group consisting of N, P, O or S, wherein at least one of the radicals R6A-R10A is selected from the group consisting of chlorine, bromine, iodine, CF3 or OR12A,
• R11A independently of one another denote hydrogen, C1-C22-alkyl, C2-C22-alkenyl, C6-C22-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, and/or two radicals R11A can also be bonded with one another to form a five-or six-membered ring,
• R12A independently of one another denote hydrogen, C1-C22-alkyl, C2-C22-alkenyl, C6-C22-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, or SiR11A3, wherein the organic radicals R12A can also be substituted by halogens, and/or in each case two radicals R12A can also be bonded with one another to form a five-or six-membered ring,
• R21A-R22A independently of one another denote hydrogen, C1-C20-alkyl, C2-C20-alkenyl, C6-C20-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, or SiR11A3, wherein the organic radicals R21A-R22A can also be substituted by halogens, and/or in each case two radicals R21A-R22A can also be bonded with one another to form a five-or six-membered ring,
• R17A and R19A independently of one another denote hydrogen, C1-C22-alkyl, C2-C22-alkenyl, C6-C22-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, NR12A2, OR12A, halogen, SiR11A3 or five-, six- or seven-membered heterocyclyl, which comprises at least one atom selected from the group consisting of N, P, O or S, wherein the organic radicals R16A-R20A can also be substituted by halogens, NR12A2, OR12A or SiR11A3 and/or in each case two radicals R16A-R20A can also be bonded with one another to form a five-, six- or seven-membered ring and/or to form a five-, six-or seven-membered heterocyclyl, which comprises at least one atom selected from the group consisting of N, P, O or S,
• E1A-E3A independently of one another denote carbon or nitrogen,
• u independently of one another are 0 for E1A-E3A as nitrogen and 1 for E1A-E3A as carbon,
• XA independently of one another denote fluorine, chlorine, bromine, iodine, hydrogen, C1-C10-alkyl, C2-C10-alkenyl, C6-C20-aryl, arylalkyl having 1-10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, NR13A2, OR13A, SR13A, SO3R13A, OC(O)R13A, CN, SCN, β-diketonate, CO, BF4−, PF6− or bulky non-coordinating anions, wherein the organic radicals XA can also be substituted by halogens and/or at least one radical R13A, and the radicals XA are, if appropriate, bonded with one another,
• R13A independently of one another denote hydrogen, C1-C22-alkyl, C2-C22-alkenyl, C6-C22-aryl, arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, or SiR14A3, wherein the organic radicals R13A can also be substituted by halogens, and/or in each case two radicals R13A can also be bonded with one another to form a five-or six-membered ring,
• R14A independently of one another denote hydrogen, C1-C20-alkyl, C2-C20-alkenyl, C6-C20-aryl, or arylalkyl having 1 to 10 C atoms in the alkyl radical and 6 to 20 C atoms in the aryl radical, wherein the organic radicals R14A can also be substituted by halogens, and/or in each case two radicals R14A can also be bonded with one another to form a five-or six-membered ring,
• s is 1, 2, 3 or 4,
• D1A, D2A are a neutral donor,
• t, y are 0 to 4, and
• GA is a simply positively charged cation,
• x is 0, 1 or 2, and
• z is 0, −1 or −2,
• wherein R7A and R16A are chlorine or bromine and R6A, R9A, R18A and R20A are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.