Oxo-nitrogenated iron complex, catalytic system comprising said oxo-nitrogenated iron complex and process for the (co)polymerization of conjugated dienes

Abstract

An oxo-nitrogenated iron complex having general formula (I) or (II) wherein: R 1 and R 2 identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C 1 -C 20 , preferably C 1 -C 15 , alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; R 3 , identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C 1 -C 20 , preferably C 1 -C 15 , alkyl groups, optionally substituted cycloalkyl groups, f optionally substituted aryl groups; X 1 and X 2 , identical or different, represent a halogen atom such as, for example, chlorine, bromine, j iodine; or are selected from linear or branched C 1 -C 20 , preferably C 1 -C 15 , alkyl groups, —OCOR 4 groups or —OR 4 groups wherein R 4 is selected from linear or branched C 1 -C 20 , preferably C 1 -C 15 , alkyl groups. Said oxo-nitrogenated iron complex having general formula (I) or (II) can be advantageously used in a catalytic system for the (co)polymerization of conjugated dienes.

1 . An oxo-nitrogenated iron complex having general formula (I) or (II): 
       
         
           
           
               
               
           
         
         wherein:
 R 1  and R 2 , identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C 1 -C 20  alkyl groups, optionally substituted cycloalkyl groups, or optionally substituted aryl groups; 
 R 3 , identical or different, represent a hydrogen atom, or are selected from linear or branched, optionally halogenated C 1 -C 20  alkyl groups, optionally substituted cycloalkyl groups, or optionally substituted aryl groups; 
 X 1  and X 2 , identical or different, represent a halogen atom; or are selected from linear or branched C 1 -C 20  alkyl groups, —OCOR 4  groups or —OR 4  groups wherein R 4  is selected from linear or branched C 1 -C 20  alkyl groups. 
 
       
     
     
         2 . Oxo-nitrogenated iron complex having general formula (I) or (II) according to  claim 1 , wherein:
 R 1  and R 2 , mutually identical, are selected from linear or branched C 1 -C 20  alkyl groups;   R 3 , mutually identical, are selected from aryl groups optionally substituted with linear or branched C 1 -C 20  alkyl groups;   X 1  and X 2 , mutually identical, are a halogen atom.   
     
     
         3 . A catalytic system for the (co) polymerization of conjugated dienes comprising:
 a) at least one oxo-nitrogenated iron complex having general formula (I) or (II) as claimed in  claim 1 ;   b) at least one co-catalyst selected from organic compounds of an element M′ different from carbon, said element M′ being selected from elements belonging to groups 2, 12, 13, or 14 of the Periodic Table of the Elements.   
     
     
         4 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 3 , wherein said co-catalyst (b) is selected from (b 1 ) aluminum alkyls having general formula (III):
   Al(X′) n (R 5 ) 3-n   (III)
   
       wherein X′ represents a halogen atom; R 5  is selected from linear or branched C 1 -C 20  alkyl groups, cycloalkyl groups, or aryl groups, said groups being optionally substituted with one or more atoms of silicon or germanium; and n is an integer ranging from 0 to 2. 
     
     
         5 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 3 , wherein said co-catalyst (b) is selected from (b 2 ) organo-oxygenated compounds of an element M′ different from carbon belonging to groups 13 or 14 of the Periodic Table of Elements. 
     
     
         6 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 3 , wherein said co-catalyst (b) is selected from (b 3 ) compounds or mixtures of organometallic compounds of an element M′ different from carbon able to react with the oxo-nitrogenated iron complex having general formula (I) or (II), extracting from this a σ-linked substituent X 1  or X 2 , to form on the one hand at least one neutral compound, and on the other hand an ionic compound consisting of a cation containing the metal (Fe) coordinated by the ligand, and an organic non-coordinating anion containing the metal M′, whose negative charge is delocalized on a multicentric structure. 
     
     
         7 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 4 , wherein said aluminum alkyls (b 1 ) having general formula (III) are di-ethyl-aluminum chloride (DEAC), mono-ethyl-aluminum dichloride (EADC), or ethyl aluminum-sesquichloride (EASC). 
     
     
         8 . A catalytic system for the (co) polymerization of conjugated dienes according to  claim 5 , wherein said organo-oxygenated compounds (b 2 ) are selected from aluminoxanes having general formula (IV):
   (R 6 ) 2 —Al—O—[—Al(R 7 )—O-] p -Al—(R) 2   (IV)
   wherein R 6 , R 7  and R 8 , identical or different, represent a hydrogen atom, a halogen atom; or are selected from linear or branched C 1 -C 20  alkyl groups, cycloalkyl groups, or aryl groups, said groups being optionally substituted with one or more atoms of silicon or germanium; and p is an integer ranging from 0 to 1000.   
     
     
         9 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 8 , wherein said organo-oxygenated compound (b 2 ) is methylaluminoxane (MAO). 
     
     
         10 . A catalytic system for the (co)polymerization of conjugated dienes according to  claim 6 , wherein said compounds or mixtures of compounds (b 3 ) are selected from organic compounds of aluminum or boron, including those represented by the following general formulae:
   [(R C ) W H 4-W ].[B(R D ) 4 ]—; B(R D ) 3 ; Al(R D ) 3 ; B(R D ) 3 Pyr; [Ph 3 C]+.[B(R D ) 4 ]—;
     [(R C ) 3 PyrH]+.[B(R D ) 4 ]—;
     [Li]+.[B(R D ) 4 ]—; [Li]+.[Al(R D ) 4 ]—
   wherein w is an integer ranging from 0 to 3, each R C  group independently represents an alkyl group or an aryl group having from 1 to 10 carbon atoms and each R D  group independently represents an aryl group partially or totally fluorinated, having from 6 to 20 carbon atoms, and Pyr represents a pyrrolyl radical optionally substituted.   
     
     
         11 . A (co)polymerization process of conjugated dienes, wherein the catalytic system according to  claim 3  is used. 
     
     
         12 . A (co)polymerization process according to  claim 11 , wherein said conjugated dienes are 1,3-butadiene or isoprene. 
     
     
         13 . A polymerization process of 1,3-butadiene or isoprene, wherein the catalytic system according to  claim 3  is used. 
     
     
         14 . Oxo-nitrogenated iron complex having general formula (I) or (II) according to  claim 1 , wherein:
 R 1  and R 2 , identical or different, represent a hydrogen atom; or are selected from linear or branched, optionally halogenated C 1 -C 15  alkyl groups, optionally substituted cycloalkyl groups, or optionally substituted aryl groups;   R 3 , identical or different, represent a hydrogen atom, or are selected from linear or branched, optionally halogenated C 1 -C 15  alkyl groups, optionally substituted cycloalkyl groups, or optionally substituted aryl groups;   X 1  and X 2 , identical or different, represent a halogen atom; or are selected from linear or branched C 1 -C 15  alkyl groups, —OCOR 4  groups or —OR 4  groups wherein R 4  is selected from linear or branched C 1 -C 15  alkyl groups.   
     
     
         15 . Oxo-nitrogenated iron complex having general formula (I) or (II) according to  claim 1 , wherein:
 R 1  and R 2 , mutually identical, are a methyl group;   R 3 , mutually identical, are selected from aryl groups optionally substituted with one or more methyl, ethyl, tert-butyl or iso-propyl groups;   X 1  and X 2 , mutually identical, are a halogen atom of chlorine, bromine, or iodine.   
     
     
         16 . A catalytic system for the (co) polymerization of conjugated dienes comprising:
 at least one oxo-nitrogenated iron complex having general formula (I) or (II) as claimed in  claim 2 ;   at least one co-catalyst selected from organic compounds of an element M′ different from carbon, said element M′ being selected from elements belonging to groups 2, 12, 13, or 14 of the Periodic Table of the Elements.   
     
     
         17 . A catalytic system for the (co) polymerization of conjugated dienes comprising:
 at least one oxo-nitrogenated iron complex having general formula (I) or (II) as claimed in  claim 1  wherein said element M′ is selected from: boron, aluminum, zinc, magnesium, gallium, or tin.