Abstract: At least one of the monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature which may be as low as 0.degree. C., in the presence of at least one radical-generator compound and at least one metal complex catalyst of formula Ma.sub.a (L).sub.n (M=Cu, Ag or Au; A=Hal, pseudohalogen or carboxylate; L=ligands of M chosen from those of formula ##STR1## R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 =H, C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic; Z.sup.1, Z.sup.2 and Z.sup.3 =one of the following: ##STR2## (R.sup.7 to R.sup.18 =H, C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic; R.sup.19 and R.sup.20 =H, Hal, C.sub.1 -C.sub.10 alkyl, C.sub.1 -C.sub.10 alkoxy or --(CR.sup.21 R.sup.22)rNR.sup.23 R.sup.24, where R.sup.21, R.sup.22, R.sup.23 and R.sup.24 =H,C.sub.1 -C.sub.10 alkyl, aromatic or heteroaromatic, and r=integer from 1 to 10; it being possible also for not more than two from among Z.sup.1, Z.sup.2 and Z.sup.

Abstract: This process is characterized in that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature which may be as low as 0.degree. C., in the presence of an initiator system comprising at least one non-peroxy radical-generator compound and at least one catalyst consisting of a metal complex represented by formula Ma.sub.a (L).sub.n in which M represents Rh, Co or Ir; A represents, a halogen or a pseudohalogen; the groups L, which may be identical or different, each represent a ligand which may be a chiral ligand, which is chosen from cyclooctadiene, PRR'R", P(OR) (OR') (OR"), NRR'R", ORR', SRR', SeRR', AsRR'R", SbRR'R", each radical R, R' and R" independently representing an optionally substituted C.sub.1 -C.sub.14 alkyl group or an optionally substituted aromatic group, it being possible for at least two of these ligands to be joined together by one or more divalent radicals; a is an integer such that 1.ltoreq.a.ltoreq.

Abstract: This process is characterized by the fact that at least one of the said monomers is polymerized or copolymerized in bulk, solution, emulsion or suspension, at a temperature that can be as low as 0.degree. C., in the presence of an initiation system including: at least one compound generating radicals, other than bromofluorene, and at least one catalyst consisting of a complex of palladium in the 0 oxidation state, denoted by the following formula (I): Pd(0)L.sup.1 L.sup.2 L.sup.3 L.sup.4 in which each of L.sup.1, L.sup.2, L.sup.3 and L.sup.4, which are identical or different, denotes a ligand which may be a chiral ligand, which is chosen from PRR'R", P(OR)(OR')(OR"), NRR'R", ORR', SRR', SeRR', AsRR'R", SbRR'R", where each of R, R' and R" independently denotes a C.sub.1 -C.sub.14 alkyl group, optionally substituted, or an optionally substituted aromatic group, it being possible for at least two of these ligands to be joined to one another by one or more divalent radicals.