Steric ploy for alternating donor-acceptor co-assembly and cooperative supramolecular polymerization.

ABSTRACT: The presence of a bulky peripheral wedge destabilizes the homo-assembly of an amide functionalized acceptor (A) monomer and thereby enables the formation of an alternating supramolecular copolymer with an amide appended donor (D) monomer via the synergistic effect of H-bonding and the charge-transfer (CT) interaction with a remarkably high K_a of 31?000 M^-1. In sharp contrast, H-bonding driven homo-polymers of A and D are formed by just replacing the bulky chains of the A monomer with linear hydrocarbons. By taking advantage of the clear difference in the critical temperature for the onset of the AA or DD homo-assemblies and DA co-assembly (T_DA ? T_AA or T_DD), the supramolecular polymerization pathway of the NDI-monomer could be fully diverted from isodesmic to cooperative in the presence of a small amount of DAN which helped the in situ production of nucleating sites involving the D-A CT-complex at a relatively higher temperature and the subsequent chain growth at T_AA following the nucleation-elongation model.

SUBMITTER: Chakraborty S 

PROVIDER: S-EPMC5356505 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature