Use of zinc derivatives as cyclic ester polymerization catalysts

Use of zinc derivatives of general formula (1)

• 4
• in which
• L1 represents a group of formula —E14(R14)(R′14)(R″14), —E15(R15)(R′15) or —E16(R16);
• E is an atom of group 15;
• L2 and L3 represent, independently, a group of formula —E14(R14)(R′14)(R″14), —E15(R15)(R′15) or —E16(R16), or form together a chain of formula —L′2—A—L′3 —;
• A represents a saturated or unsaturated chain comprising one, two or three elements of group 14, each being optionally and independently substituted by one of the following substituted or non-substituted radicals:
• alkyl, cycloalkyl, aryl, in which said substituent is a halogen atom, the alkyl, aryl, nitro or cyano radical;
• L′2 and L′3 represent, independently, a group of formula —E14(R14)(R′14)—,
• —E15(R15)— or —E16—;
• E14 is an element of group 14;
• E15 is an element of group 15;
• E16 is an element of group 16;
• R14, R′14, R″14, R15, R′15 and R16 represent, independently, the hydrogen atom;
• one of the following substituted or non-substituted radicals:
• alkyl, cycloalkyl or aryl, in which said substituent is a halogen atom, the alkyl, cycloalkyl, aryl, nitro or cyano radical;
• a radical of formula —E'14RR′R″;
• E'14 is an element of group 14;
• R, R′ and R″ represent, independently, the hydrogen atom or one of the following substituted (by one or more identical or different substituents) or non-substituted radicals:
• alkyl, cycloalkyl, aryl, in which said substituent is a halogen atom, the alkyl, aryl, nitro or cyano radical;
• as cyclic ester (co)polymerization catalysts.