Fig. 2. Aggregate types and pathways for a S-Mn and b S-Zn and co-assembled mixtures thereof.

a While S/R-Mn can only be monomeric or form a dimer, (b) S-Zn can aggregate via a cooperative mechanism to H-aggregates or via an isodesmic pathway to J-type aggregates. The achiral J-aggregate can be chain-capped by both S- and R-Mn, but the chiral H-aggregate can only interact with S-Mn as a chain-capper, introducing the possibility for enantioselective chain-capping of polymers.