Brush Polymer of Donor-Accepter Dyads via Adduct Formation between Lewis Base Polymer Donor and All Carbon Lewis Acid Acceptor

A synthetic method that taps into the facile Lewis base (LB)→Lewis acid (LA) adduct forming reaction between the semiconducting polymeric LB and all carbon LA C(60) for the construction of covalently linked donor-acceptor dyads and brush polymer of dyads is reported. The polymeric LB is built on poly(3-hexylthiophene) (P3HT) macromers containing either an alkyl or vinyl imidazolium end group that can be readily converted into the N-heterocyclic carbene (NHC) LB site, while the brush polymer architecture is conveniently constructed via radical polymerization of the macromer P3HT with the vinyl imidazolium chain end. Simply mixing of such donor polymeric LB with C(60) rapidly creates linked P3HT-C(60) dyads and brush polymer of dyads in which C(60) is covalently linked to the NHC junction connecting the vinyl polymer main chain and the brush P3HT side chains. Thermal behaviors, electronic absorption and emission properties of the resulting P3HT-C(60) dyads and brush polymer of dyads have been investigated. The results show that a change of the topology of the P3HT-C(60) dyad from linear to brush architecture enhances the crystallinity and T(m) of the P3HT domain and, along with other findings, they indicate that the brush polymer architecture of donor-acceptor domains provides a promising approach to improve performances of polymer-based solar cells.