Catalysts containing N-pyrrolyl substituted nitrogen donors

Abstract

Catalyst compositions useful for the polymerization or oligomerization of olefins are disclosed. Certain of the catalyst compositions comprise N-pyrrolyl substituted nitrogen donors. Also disclosed are processes for the polymerization or oligomerization of olefins using the catalyst compositions.

We claim:  
     
         1 . A catalyst composition for the polymerization of olefins, comprising a Ti, Zr, or Hf complex of a dianionic bidentate ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom substituted by a 1-pyrrolyl or substituted 1-pyrrolyl group; wherein the remaining donor atoms of the ligand are selected from the group consisting of C, N, P, As, O, S, and Se.  
     
     
         2 . The catalyst composition according to  claim 1 , wherein the metal complex is a compound of formula XIV:  
       
         
           
           
               
               
           
         
       
       wherein: 
 M is Zr or Ti;  
 D 1 , D 2 , and G collectively comprise the dianionic bidentate ligand;  
 D 1  and D  2  are monodentate donors linked by a bridging group G, wherein at least one of D 1  and D 2  is ligated to the metal M by a nitrogen atom substituted by a 1-pyrrolyl or a substituted 1-pyrrolyl group;  
 T is H, hydrocarbyl, substituted hydrocarbyl, or other group capable of inserting an olefin; and  
 X −  is a weakly coordinating anion.  
 
     
     
         3 . The catalyst composition according to  claim 2 , wherein the dianionic bidentate ligand is selected from Set 7, or a tautomer thereof:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 3a-h  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-h  may be linked by a bridging group; and  
 G 4  is a divalent bridging hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl.  
 
     
     
         4 . The catalyst composition according to  claim 1 , which is attached to a solid support.  
     
     
         5 . A process for the polymerization of olefins, which comprises contacting one or more olefins with the catalyst composition of  claim 1 , and optionally an aluminum or boron-centered Lewis acid.  
     
     
         6 . A catalyst composition for the polymerization of olefins, comprising a Ti, Zr, or Hf complex of a monoanionic bidentate ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom substituted by a 1-pyrrolyl or substituted 1-pyrrolyl group; wherein the remaining donor atoms of the ligand are selected from the group consisting of C, N, P, As, O, S, and Se.  
     
     
         7 . The catalyst composition according to  claim 6 , optionally further comprising a second compound Y, wherein the metal complex is a compound of formula XV:  
       
         
           
           
               
               
           
         
       
       wherein: 
 M is Ti, Zr, or Hf;  
 m and n are integers, defined as follows: when M is Ti and m is 1, n is 2 or 3; when M is Ti and m is 2, n is 1 or 2; when M is Zr and m is 1, n is 3; when M is Zr and m is 2, n is 2; when M is Hf, m is 2 and n is 2;  
 R 3a-i  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, boryl, fluoro, chloro, bromo, or nitro, with the proviso that R 3e  is other than halogen or nitro; in addition, any two of R 3a-i  on the same or different N-pyrrol-1-yliminophenoxide ligand may be linked by a bridging group;  
 Z is H, halogen, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, allyl, benzyl, alkoxy, carboxylate, amido, nitro, or trifluoromethane sulfonyl; each Z may be the same or different and plural Z may be taken together to form sulfate, oxalate, or another divalent group;  
 Y is selected from the group consisting of a neutral Lewis acid capable of abstracting Z −  to form a weakly coordinating anion, a cationic Lewis acid whose counterion is a weakly coordinating anion, and a Bronsted acid whose conjugate base is a weakly coordinating anion; and  
 when n is 2 or 3, the metal complex may be a salt, comprising a Ti, Zr, or Hf centered cation with one of the groups Z −  being a weakly coordinating anion.  
 
     
     
         8 . The catalyst composition according to claims  6  or  7 , wherein the monoanionic bidentate ligand is selected from Set 8, or a tautomer thereof:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 2x  is H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl; and  
 R 3a-d,f-i  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-d,f-i  may be linked by a bridging group.  
 
     
     
         9 . The catalyst composition according to  claim 6 , which is attached to a solid support.  
     
     
         10 . A process for the polymerization of olefins, which comprises contacting one or more olefins with the catalyst composition of  claim 6 , and optionally a second compound Y; wherein Y is selected from the group consisting of (i) a neutral Lewis acid which is capable of reacting with said Ti, Zr, or Hf complex to form a salt comprising a weakly coordinating anion, (ii) a cationic Lewis acid whose counterion is a weakly coordinating anion, and (iii) a Bronsted acid whose conjugate base is a weakly coordinating anion.  
     
     
         11 . A catalyst composition for the polymerization of olefins, comprising a Cr, Mo, or W complex of a monodentate dianionic ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom substituted by a 1-pyrrolyl or substituted 1-pyrrolyl group; wherein the remaining donor atoms of the ligand are selected from the group consisting of C, N, P, As, O, S, and Se.  
     
     
         12 . The catalyst composition according to  claim 11 , optionally further comprising a second compound Y, wherein the metal complex is a compound of formula XVI:  
       
         
           
           
               
               
           
         
       
       wherein: 
 M is Cr, Mo, or W;  
 D 1  and D 2  are monodentate dianionic ligands that may be linked by a bridging group to collectively comprise a bidentate tetraanionic ligand;  
 Z 1a  and Z 1b  are each, independently H, halogen, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, allyl, benzyl, alkoxy, carboxylate, amido, nitro, trifluoromethanesulfonyl, or may be taken together to form sulfate, oxalate, or another divalent group;  
 Y is selected from the group consisting of a neutral Lewis acid capable of abstracting (Z 1a ) −  or (Z 1b ) −  to form a weakly coordinating anion, a cationic Lewis acid whose counterion is a weakly coordinating anion, and a Bronsted acid whose conjugate base is a weakly coordinating anion; and wherein  
 the metal complex may be a salt, comprising a Cr, Mo, or W centered cation with one of (Z 1a ) −  or (Z 1b ) −  being a weakly coordinating anion.  
 
     
     
         13 . The catalyst composition according to  claim 12 , wherein the metal is Cr and the monodentate dianionic ligand is selected from Set 9, or a tautomer thereof:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 3a-d  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-d  may be linked by a bridging group.  
 
     
     
         14 . The catalyst composition according to  claim 11 , which is attached to a solid support.  
     
     
         15 . A process for the polymerization of olefins, which comprises contacting one or more olefins with the catalyst composition of claims  11 , and optionally a second compound Y; wherein Y is selected from the group consisting of (i) a neutral Lewis acid which is capable of reacting with said Cr, Mo, or W complex to to form a salt comprising a weakly coordinating anion, (ii) a cationic Lewis acid whose counterion is a weakly coordinating anion, and (iii) a Bronsted acid whose conjugate base is a weakly coordinating anion.  
     
     
         16 . A catalyst composition for the polymerization of olefins, comprising a V, Nb, or Ta complex of a monodentate dianionic ligand, wherein at least one of the donor atoms of the ligand is a nitrogen atom substituted by a 1-pyrrolyl or substituted 1-pyrrolyl group; wherein the remaining donor atoms of the ligand are selected from the group consisting of C, N, P, As, O, S, and Se.  
     
     
         17 . The catalyst composition according to  claim 16 , optionally further comprising a second compound Y wherein the metal complex is a compound of formula XVII:  
       
         
           
           
               
               
           
         
       
       wherein: 
 M is V, Nb, or Ta;  
 R 3a-d  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, boryl, fluoro, chloro, bromo, or nitro; in addition, any two of R 3a-d  may be linked by a bridging group;  
 T 1b  is hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, cyclopentadienyl, substituted cyclopentadienyl, N(hydrocarbyl) 2 , O(hydrocarbyl), or halide;  
 Z 1a  and Z 1b  are each, independently H, halogen, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, allyl, benzyl, alkoxy, carboxylate, amido, nitro, trifluoromethane sulfonyl, or may be taken together to form sulfate, oxalate, or another divalent group;  
 Y is selected from the group consisting of a neutral Lewis acid capable of abstracting (Z 1a ) −  or (Z 1b ) −  to form a weakly coordinating anion, a cationic Lewis acid whose counterion is a weakly coordinating anion, and a Bronsted acid whose conjugate base is a weakly coordinating anion; and  
 the metal complex may be a salt, comprising a V, Nb, or Ta centered cation with one of (Z 1a ) −  or (Z 1b ) −  being a weakly coordinating anion.  
 
     
     
         18 . The catalyst composition according to  claim 17 , wherein the monodentate dianionic ligand is selected from Set 10, or a tautomer thereof, and T 1b  is a N(hydrocarbyl) 2  group:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 3a-d  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-d  may be linked by a bridging group.  
 
     
     
         19 . The catalyst composition according to  claim 16 , wherein M is V.  
     
     
         20 . The catalyst composition according to claims  16 , which is attached to a solid support.  
     
     
         21 . A process for the polymerization of olefins, which comprises contacting one or more olefins with the catalyst composition of claims  16 , and optionally a second compound Y; wherein Y is selected from the group consisting of (i) a neutral Lewis acid which is capable of reacting with said V, Nb, or Ta complex to to form a salt comprising a weakly coordinating anion, (ii) a cationic Lewis acid whose counterion is a weakly coordinating anion, and (iii) a Bronsted acid whose conjugate base is a weakly coordinating anion.  
     
     
         22 . A catalyst composition for the polymerization of olefins, comprising (i) a cationic Ti, Zr or Hf complex of a mono- or dianionic, nitrogen donor ligand, wherein said nitrogen donor is substituted by a 1-pyrrolyl or substituted 1-pyrrolyl group and is linked by a bridging group to a cyclopentadienyl, phosphacyclopentadienyl, pentadienyl, 6-oxacyclohexadienyl, or borataaryl group which is also ligated to said metal, and optionally, (ii) an aluminum or boron-centered Lewis acid.  
     
     
         23 . The catalyst composition according to  claim 22 , wherein the mono- or dianionic, nitrogen donor ligand is selected from Set 11, or a tautomer thereof:  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 2a  is H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, boryl, or ferrocenyl;  
 R 3a-h  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-h  may be linked by a bridging group;  
 R 4a  is hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl; and  
 G is a divalent bridging hydrocarbyl, substituted hydrocarbyl, silyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl.  
 
     
     
         24 . The catalyst composition according to  claim 22 , wherein said composition is attached to a solid support.  
     
     
         25 . A process for the polymerization olefins, which comprises contacting one or more olefins with the catalyst composition of claims  22 .  
     
     
         26 . A process for the polymerization or oligomerization of olefins, comprising contacting one or more olefins with a catalyst composition comprising a Group 8-10 transition metal complex, wherein said catalyst composition exhibits improved thermal stability, and wherein said metal complex comprises a bidentate or variable denticity ligand comprising one or two nitrogen donor atom or atoms independently substituted by an aromatic or heteroaromatic ring, wherein the ortho positions of said ring(s) are substituted by groups other than H or alkyl; provided that at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group.  
     
     
         27 . A process for the polymerization or oligomerization of olefins, comprising contacting one or more olefins with a catalyst composition comprising a Group 8-10 transition metal complex, wherein said catalyst composition exhibits improved stability in the presence of an amount of hydrogen effective to achieve chain transfer, and wherein said metal complex comprises a bidentate or variable denticity ligand comprising one or two nitrogen donor atom or atoms independently substituted by an aromatic or heteroaromatic ring, wherein the ortho positions of said ring(s) are substituted by groups other than H or alkyl; provided that at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group.  
     
     
         28 . A process for the polymerization or oligomerization of olefins, comprising contacting one or more olefins with a catalyst composition comprising a Group 8-10 transition metal complex, wherein said catalyst composition exhibits either improved thermal stability, or exhibits improved stability in the presence of an amount of hydrogen effective to achieve chain transfer, or both, wherein said metal complex comprises a bidentate or variable denticity ligand comprising one or two nitrogen donor atom or atoms independently substituted by an aromatic or heteroaromatic ring, wherein at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group which is capable of reversibly forming an agostic bond to said Group 8-10 transition metal under olefin polymerization reaction conditions.  
     
     
         29 . A process for the polymerization or oligomerization of olefins, comprising contacting one or more olefins with a catalyst composition comprising a Group 8-10 transition metal complex, wherein said catalyst composition exhibits either improved thermal stability, or exhibits improved stability in the presence of an amount of hydrogen effective to achieve chain transfer, or both, wherein said composition comprises a bidentate or variable denticity ligand comprising one or two nitrogen donor atom or atoms independently substituted by an aromatic or heteroaromatic ring, wherein the ortho positions of said ring(s) are substituted by groups other than H or alkyl; provided that at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group.  
     
     
         30 . The process according to claims  26 ,  27 ,  28 , or  29 , wherein the ortho positions of said aromatic or heteroaromatic ring are substituted by aryl or heteroaryl groups.  
     
     
         31 . The process according to claims  26 ,  27 ,  28 ,  29 , or  30 , wherein the half-life for thermal decomposition is greater than 10 min in solution at 60° C., 200 psig ethylene, and the average apparent catalyst activity of said catalyst is greater than 100,000 mol C 2 H 4 /mol catalyst/h.  
     
     
         32 . The process according to  claim 31 , wherein the half-life for thermal decomposition is greater than 20 minutes, and the average apparent catalyst activity of said catalyst is greater than 1,000,000 mol C 2 H 4 /mol catalyst/h.  
     
     
         33 . The process according to  claim 31 , wherein the half-life for thermal decomposition of said catalyst is greater than 30 min.  
     
     
         34 . The process according to  claim 31 ,  32 , or  33  wherein the Group 8-10 transition metal is Ni.  
     
     
         35 . The process according to claims  26 ,  27 ,  28 ,  29 , or  30 , wherein the process temperature is between about 60 and about 150° C.  
     
     
         36 . The process according to  claim 35 , wherein the process temperature is between about 100 and about 150° C.  
     
     
         37 . The process according to claims  26 ,  27 ,  28 ,  29 , or  30 , wherein the bidentate or variable denticity ligand is selected from Set 12:  
       
         
           
           
               
               
           
         
       
       wherein: 
 R 6a  and R 6b  are each independently an aromatic or heteroaromatic ring wherein the ortho positions of said ring(s) are substituted by groups other than H or alkyl; provided that at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group;  
 and R 2x  and R 2y  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl, and may be linked by a bridging group.  
 
     
     
         38 . The process according to  claim 37 , wherein the Group 8-10 transition metal is nickel and the bidentate or variable denticity ligand is selected from Set 13:  
       
         
           
           
               
               
           
         
       
       wherein: 
 R 7a-d  are groups other than H or alkyl; provided that at least one of R 7a-d  is an aryl or heteroaryl group;  
 R 2x  and R 2y  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl, and may be linked by a bridging group; and  
 R 3a-f  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-f  may be linked by a bridging group.  
 
     
     
         39 . The process according to  claim 38 , wherein the composition is attached to a solid support.  
     
     
         40 . The process according to  claim 39 , wherein the process temperature is between about 60 and about 100° C.  
     
     
         41 . A process for olefin polymerization comprising: contacting one or more olefin monomers with a single site catalyst attached to a solid support, wherein said catalyst comprises a cationic Group 4-11 transition metal complex and a weakly coordinating counteranion, and wherein said catalyst is introduced into a gas phase olefin polymerization reactor in an inactive form which is activated by reaction with a second compound Y 1  to form said catalyst in said reactor; wherein Y 1  is a volatile, Lewis acidic, metal hydrocarbyl.  
     
     
         42 . The process according to  claim 41 , wherein said transition metal is selected from the group consisting of Ti, Zr and Hf.  
     
     
         43 . The process according to  claim 41 , wherein said transition metal is selected from the group consisting of Ni, Co, and Fe.  
     
     
         44 . The process according to claims  41 ,  42 , or  43 , wherein Y 1  is a trialkylaluminum or dialkylzinc.  
     
     
         45 . The process according to  claim 44 , wherein Y 1  is trimethylaluminum.  
     
     
         46 . The process according to  claim 41 , wherein (i) said inactive form of said catalyst is selected from Set 14, (ii) said weakly coordinating counteranion is either formed by reaction of said inactive form of said catalyst with Y 1  , or is selected from the group consisting of B(C 6 F 5 ) 4   − ,B(3,5-bis(trifluoromethyl)phenyl) 4   − , [(C 6 F 5 ) 3 B-(imidazole)-B(C 6 F 5 ) 3]   − , BF 4   − , and [(C 6 F 5 ) 3 B—CN—B(C 6 F 5 ) 3 ] − , and (iii) Y 1  is trimethylaluminum;  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 2a,b,x,y  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, silyl, boryl, or ferrocenyl; in addition, any two of R 2a,b,x,y  may be linked by a bridging group;  
 R 3a-m  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-m  may be linked by a bridging group;  
 A 1  is halide or a monoanionic group which is capable of reacting with Y 1  to generate an active olefin polymerization catalyst, provided that in the absence of Y 1  , A 1  is such that said inactive form of said single site catalyst is at least 10 times less active as a catalyst for olefin polymerization than said active olefin polymerization catalyst;  
 A 2  and A 3  are each independently hydrocarbyl, halide, O(hydrocarbyl) or O(substituted hydrocarbyl), provided that at least one of A 2  and A 3  is capable of being abstracted by Y 1  to form a weakly coordinating counteranion, and the other is either capable of inserting an olefin to initiate polymer chain growth, or is capable of being exchanged with a group on Y 1  which can then initiate chain growth;  
 G and G 4  are divalent bridging hydrocarbyl, substituted hydrocarbyl, silyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl;  
 Y 1  is a trialkylaluminum or dialkylzinc; and  
 X −  is a weakly coordinating anion.  
 
     
     
         47 . The process according to claims  26 ,  27 ,  28 ,  29 , or  30 , wherein said catalyst is introduced into a gas phase olefin polymerization reactor in an inactive form attached to a solid support, and wherein said catalyst is activated by a second compound Y 1  in said reactor.  
     
     
         48 . The process according to  claim 47 , wherein said bidentate or variable denticity ligand is selected from Set 15;  
       
         
           
           
               
               
           
         
       
       wherein: 
 R 6a  and R 6b  are each independently an aromatic or heteroaromatic ring wherein the ortho positions of said ring(s) are substituted by groups other than H or alkyl; provided that at least one of the ortho positions of at least one of said aromatic or heteroaromatic rings is substituted by an aryl or heteroaryl group;  
 and R 2x  and R 2y  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl, and may be linked by a bridging group.  
 
     
     
         49 . The process according to  claim 48 , wherein (i) said Group 8-10 transition metal is nickel, (ii) said weakly coordinating counteranion is either formed by reaction of said inactive form of said catalyst with a volatile second compound Y 1 , or is selected from the group consisting of B(C 6 F 5 ) 4   − , B(3,5-bis(trifluoromethyl)phenyl) 4   − , [(C 6 F 5 ) 3 B-(imidazole)-B(C 6 F 5 ) 3 ] − , BF 4   − , and [(C 6 F 5 ) 3 B—CN—B(C 6 F 5 ) 3 ] − , (iii) Y 1  is trimethylaluminum, and (iv) said bidentate or variable denticity ligand is selected from Set 16;  
       
         
           
           
               
               
           
         
       
       wherein: 
 R 7a-d  are groups other than H or alkyl; provided that at least one of R 7a-d  is an aryl or heteroaryl group;  
 R 2x  and R 2y  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, or heteroatom connected substituted hydrocarbyl, and may be linked by a bridging group; and  
 R 3a-f  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-f  may be linked by a bridging group.  
 
     
     
         50 . The process according to claims  26 ,  27 ,  28 ,  29 , or  30 , wherein said aromatic or heteroaromatic ring is selected from Set 17;  
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       wherein: 
 R 7a,b  are groups other than H or alkyl; provided that at least one of R 7a,b  is an aryl or heteroaryl group;  
 R 3a-k  are each independently H, hydrocarbyl, substituted hydrocarbyl, heteroatom connected hydrocarbyl, heteroatom connected substituted hydrocarbyl, fluoroalkyl, silyl, boryl, fluoro, chloro, bromo, cyano, or nitro; in addition, any two of R 3a-k  may be linked by a bridging group; and  
 E 5  is O, S, Se, or NR 3b .