Bimetallic zinc complex and process of producing polycarbonate using the same as polymerization catalyst

A bimetallic zinc complex having formula 1:

• wherein
• each of N˜N chelate ligands is a monovalent anion and together with zinc forms a 6-membered ring,
• R1 is a C1-C20 alkyl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom or a C6-C20 aryl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, and the R1 radicals are either identical or different from each other,
• R2 is a hydrogen atom, a halogen atom, a cyanide radical, or a C1-C20 alkyl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, or a C6-C20 aryl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, and the R2 radicals are either identical or different from each other,
• R3 is a hydrogen atom, a halogen atom, a cyanide radical, or a C1-C20 alkyl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, or a C6-C20 aryl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, and the R3 radicals are either identical or different from each other,
• R4 is a hydrogen atom, a halogen atom, a cyanide radical, or a C1-C20 alkyl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, or a C6-C20 aryl radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, and the R4 radicals are either identical or different from each other,
• either R2 and R3, or R3 and R4 may be linked to each other to form a ring,
• X is a monovalent anion selected from a C1-C20 alkoxy radical having at least one hydrogen atom unsubstituted or substituted by a halogen atom, carboxy, alkylsulfinato, and amido, and the X monovalent anions are either identical or different from each other and each X may be coordinated to only a metallic zinc atom or form a bridged structure between two metallic zinc atoms,
• Y is a carbon diradical and may have at least one hydrogen substituted by halogen, and the Y diradicals are either identical or different from each other, and
• Q is a C1-C20 alkyl diradical having at least one hydrogen atom unsubstituted or substituted by a halogen atom or a C6-C20 aryl diradical having at least one hydrogen atom unsubstituted or substituted by a halogen atom.