Process for preparing polycarbonate and catalytic system used

1. A process for preparing polycarbonate comprising copolymerizing an epoxy compound and carbon dioxide (CO 2 ) in the presence of a catalytic system comprising:

at least one catalyst selected from complexes of a transition metal having general formula (I):

wherein:

E represents a metal atom selected from the group consisting of chromium, manganese, iron, cobalt, nickel, and aluminum;

R 1 , R 2 , R 3 , R 4 , R 5 and R 6 , identical or different, represent a hydrogen atom or are selected from the group consisting of linear or branched, saturated or unsaturated, C 1 -C 20 alkyl groups, optionally containing heteroatoms; optionally substituted aryl groups; optionally substituted heteroaryl groups; optionally substituted cycloalkyl groups; and optionally substituted heterocyclic groups;

or R 2 and R 3 and/or R 5 and R 6 , may optionally be linked together to form, together with the other atoms to which they are linked, a saturated, unsaturated or aromatic cycle containing from 1 to 12 carbon atoms, which may optionally be substituted with linear or branched, saturated or unsaturated, C 1 -C 20 alkyl groups, optionally containing heteroatoms, optionally substituted aryl groups, optionally substituted heteroaryl groups, optionally substituted cycloalkyl groups, optionally substituted heterocyclic groups, trialkyl- or triarylsilyl groups, dialkyl- or diaryl-amine groups, dialkyl- or diaryl-phosphine groups, linear or branched, saturated or unsaturated C 1 -C 20 alkoxy groups, optionally substituted aryloxy groups, optionally substituted thioalkoxy or thioaryloxy groups, and cyano groups, said cycle optionally containing heteroatoms selected from the group consisting of oxygen, sulfur, nitrogen, silicon, phosphorus, selenium, oxygen, and nitrogen;

Y represents a halogen anion selected from the group consisting of a fluoride anion, a chloride anion, a bromide anion, and an iodide anion an inorganic anion selected from the group consisting of an azide anion, a hydroxide anion, an amide anion, a perchlorate anion, a chlorate anion, a sulfate anion, a phosphate anion, and a nitrate anion or an organic anion selected from the group consisting of a C 1 -C 20 alcoholate anion, a C 1 -C 20 thioalcoholate anion, a C 1 -C 30 carboxylate anion, and a C 1 -C 30 alkyl- or dialkyl-amide anion;

Z represents a divalent organic radical having general formula (III), (IV) or (V):

wherein:

R 11 , R 12 , R 13 , R 14 , R 15 and R 16 , identical or different, represent a hydrogen atom; or are selected from the group consisting of linear or branched, saturated or unsaturated C 1 -C 20 alkyl groups, optionally containing heteroatoms; optionally substituted aryl groups; optionally substituted heteroaryl groups; optionally substituted cycloalkyl groups; and optionally substituted heterocyclic groups;

or R 11 and R 12 in general formula (III) or in general formula (IV), or R 11 and R 13 in general formula (IV), or R 11 and R 15 or R 11 and R 16 in general formula (V), may optionally be linked together to form together with the other atoms to which they are linked, a saturated, unsaturated or aromatic cycle containing from 1 to 12 carbon atoms, which may optionally be substituted with linear or branched, saturated or unsaturated, C 1 -C 20 alkyl groups optionally containing heteroatoms, optionally substituted aryl groups, optionally substituted heteroaryl groups, optionally substituted cycloalkyl groups, optionally substituted heterocyclic groups, trialkyl- or trialyl-silyl groups, dialkyl or diaryl-amine groups, dialkyl- or diaryl-phosphine groups, linear or branched, saturated or unsaturated, C 1 -C 20 alkoxyl groups, optionally substituted aryloxy groups, optionally substituted thioalkoxy or thioaryloxy groups, cyano groups, said cycle optionally containing heteroatoms selected from the group consisting of oxygen, sulfur, nitrogen, silicon, phosphorous, and selenium;

at least one co-catalyst,

wherein the at least one co-catalyst is triphenyl(4-pyridinylmethyl)phosphonium chloride hydrochloride (UHFFA).