The present invention relates to dithiocarbamic esters, their preparation and their use for regulating the degree of polymerization during the polymerization of monomers, such as during the polymerization of chloroprene to give polychloroprene, and during the polymerization of 2,3-dichlorobutadiene to give poly-2,3-dichlorobutadiene, and during the copolymerization of chloroprene with 2,3-dichlorobutadiene. The present invention further relates to polymers which are obtainable via the polymerization of monomers in the presence of the dithiocarbamic esters of the invention. The present invention also relates to polymers which contain end groups derived from the dithiocarbamic esters of the present invention.