Synchronization in Non-Mirror-Symmetrical Chirogenesis: Non-Helical π–Conjugated Polymers with Helical Polysilane Copolymers in Co-Colloids

Abstract

A curious question is whether two types of chiroptical amplifications, called sergeants-and-soldiers (Ser-Sol) and majority-rule (Maj) effects, between non-charged helical copolymers and non-charged, non-helical homopolymers occur when copolymer encounter homopolymer in co-colloids. To address these topics, the present study chose (i) two helical polysilane copolymers (HCPSs) carrying (S)- or (R)-2-methylbutyl with isobutyl groups as chiral/achiral co-pendants (type I) and (S)- and (R)-2-methylbutyl groups as chiral/chiral co-pendants (type II) and (ii) two blue luminescent π-conjugated polymers, poly[(dioctylfluorene)-alt-(trans-vinylene)] (PFV8) and poly(dioctylfluorene) (PF8). Analyses of circular dichroism (CD) and circularly polarized luminescence (CPL) spectral datasets of the co-colloids indicated noticeable, chiroptical inversion in the Ser-Sol effect of PFV8/PF8 with type I HCPS. PF8 with type IIHCPS showed the anomalous Maj rule with chiroptical inversion though PFV8 with type IIHCPS was the normal Maj effect. The noticeable non-mirror-symmetric CD-and-CPL characteristics and marked differences in hydrodynamic sizes of these colloids were assumed to originate from non-mirror-symmetrical main-chain stiffness of HCPSs in dilute toluene solution. The present chirality/helicity transfer experiments alongside of previous/recent publications reported by other workers and us allowed to raise the fundamental question; is mirror symmetry on macroscopic levels in the ground and photoexcited states rigorously conserved?