Racemate-forming enantiomer-differentiating polymerization

Note 2 A polymerization in which, starting from the racemate of a chiral monomer, two types of polymer molecules, each containing monomeric units derived from one of the enantiomers, form in equal amounts is termed racemate-forming enantiomer-differentiating polymerization . The resulting polymer is optically inactive (see Note 4 of Definition 2). 

The isoselective polymerization of a racemic mixture of monomers can proceed in two ways depending on initiator, monomer, and reaction conditions. Racemate-forming enantiomer-differentiating polymerization involves both the R and 5 monomers polymerizing at the same rate hut without any cross-propagation [Hatada et al., 2002]. A racemic monomer mixture polymerizes to a racemic mixture of all-5 and all-5 polymer molecules [Pino, 1965 ... 

In the literature concerning the ROP of heterocyclic monomers, the asymmetric, enantiomer-differentiating polymerization and racemate-forming enantiomer-differentiating polymerization are informally named... 

Stereoselective (IDRAG racemate-forming enantiomer-differentiating polymerization)... 

The tendency of the sec-butyl group to chiral disordering led [30], however, to the possibility of achieving an absolute asymmetric polymerization. Racemic (1) is dimorphic. Crystalline form >1, which may be obtained from the melt, has space group Pi with Z= 1 and cell constants a = 13.35, b = 7.02, c = 5.42, a = 104°,i8 = 93°, y = 92°. These cell constants are similar to, but significantly different from, those of crystals of the resolved monomer. Thus crystallization of racemic (1) involves not spontaneous resolution but formation of a solid solution of the two enantiomers. Details of the X-ray diffraction patterns as also results by differential scanning calorimetry support this view. Thus we have an example of the behavior ... 

---