Controlled Radical Polymerization, and Catalysts Useful Therein

Abstract

A catalyst is prepared in situ by reaction between an aryl halide and a Ni-ligand complex. The catalyst may be used to promote chain-growth polymerization of halogen-substituted Mg or Zn monomers. Polymers, copolymers, block copolymers, polymer thin films, and surface-confined polymer brushes may be produced using the catalyst.

What is claimed: 
     
         1 . A process for synthesizing a polymer, said process comprising polymerizing a first monomer X′-Ar′-MX″ in the presence of a catalyst; 
       wherein:
 X′ denotes a monovalent halide; 
 Ar′ denotes substituted or unsubstituted aryl; 
 M denotes Mg or Zn; 
 X″ denotes a monovalent halide; 
 
       the catalyst comprises a complex ArNiLX;
 Ar denotes substituted or unsubstituted aryl; 
 L denotes a bidentate ligand; 
 X denotes a monovalent anion; and 
 X, X′, and X″ may be the same or different. 
 
     
     
         2 . The process of  claim 1 , wherein the catalyst is covalently bound to a surface via a linker moiety, whereby the resulting polymer is covalently bound to the surface. 
     
     
         3 . The process of  claim 2 , wherein the linker moiety is selected from the group consisting of silyl, phosphonate, carboxylate, and (CH 2 ) n . 
     
     
         4 . The process of  claim 1 , wherein the resulting polymer has 95% or greater regioregularity. 
     
     
         5 . A process for synthesizing a block copolymer, said process comprising continuing the polymerization process of  claim 1  after a time with a second monomer X′-Ar″-MX″ wherein
 Ar″ denotes substituted or unsubstituted aryl, wherein Ar″ is different from Ar′; and 
 X′, M, and X″ are as previously defined; wherein each of X′, M, and X″, respectively, are identical or nonidentical in the first and second monomers. 
 
     
     
         6 . The process of  claim 1 , wherein:
 Ar denotes substituted or unsubstituted, fused or unfused benzene, thiophene, pyrrole, or furan,   L denotes substituted or unsubstituted diphosphine; and   X denotes a monovalent halide.   
     
     
         7 . The process of  claim 1 , wherein:
 Ar denotes bithiophen-2-yl;   L is 1,3-bis(diphenylphosphino)propane; and   X denotes bromide.   
     
     
         8 . The process of  claim 1 ; additionally comprising the step of synthesizing the catalyst by reacting in solution Ar—X with NiL 2 , wherein X is a halogen. 
     
     
         9 . The process of  claim 8 , wherein:
 Ar denotes substituted or unsubstituted, fused or unfused benzene, thiophene, pyrrole, or furan, and   L 2  denotes two identical or nonidentical, substituted or unsubstituted diphosphines L.   
     
     
         10 . The process of  claim 8 , wherein:
 Ar denotes bithiophen-2-yl;   each L is 1,3-bis(diphenylphosphino)propane, and   X denotes bromine.   
     
     
         11 . The process of  claim 8 , additionally comprising the step, after the catalyst is synthesized and before the polymer is synthesized, of storing the catalyst in solution. 
     
     
         12 . The process of  claim 11 , wherein the catalyst is stored in solution under refrigeration. 
     
     
         13 . The process of  claim 12 , wherein the catalyst is stored in solution under refrigeration for at least one month after the catalyst is synthesized and before the polymer is synthesized.