Patent ID: 8604155

Claim:
A polymerization system for the copolymerization of CO 2 and epoxides, the system comprising: a metallosalenate metal complex; and a chain transfer agent having a plurality of sites capable of initiating copolymerization of epoxides and CO 2 ; wherein: the chain transfer agent has a structure Y-A-(Y) n , each Y group is independently selected from the group consisting of: —OH, —C(O)OH, —C(OR y )OH, —OC(R y )OH, —NHR y , —NHC(O)R y , —NHC═NR y ; —NR y C═NH; —NR y C(NR y 2 )═NH; —NHC(NR y 2 )═NR y ; —NHC(O)OR y , —NHC(O)NR y 2 ; —C(O)NHR y , —C(S)NHR y , —OC(O)NHR y , —OC(S)NHR y , —SH, —C(O)SH, —B(OR y )OH, —P(O) a (R y ) b (OR y ) c (O) d H, —OP(O) a (R y ) b (OR y ) c (O) d H, —N(R y )OH, —ON(R y )H; ═NOH, ═NN(R y )H, where each occurrence of R y is independently —H, or an optionally substituted radical selected from the group consisting of C 1-20 aliphatic, C 1-20 heteroaliphatic, 3- to 12-membered heterocyclic, and 6- to 12-membered aryl, a and b are each independently 0 or 1, c is 0, 1 or 2, d is 0 or 1, and the sum of a, b, and c is 1 or 2 and where an acidic hydrogen atom bound in any of the above functional groups may be replaced by a metal atom or an organic cation -A- is a covalent bond or a multivalent moiety; and n is an integer between 1 and 10, inclusive.