Double helix-like assembly of axially chiral 3,3′-Bi(benzo[b]thiophene-S,S-dioxide) Derivative in crystals and circularly polarized luminescence

The assembly behavior and the development in circularly polarized luminescence (CPL) materials of axially chiral molecules have become an attractive research topic in material chemistry. This study reports the facile syntheses of 3,3′-bibenzo[b]thiophene and its thienyl-S,S-dioxidized derivatives modified with N-phenylcarbazole and triphenylamine, respectively. The obtained four compounds display blue-to-red luminescence with large Stokes shifts. Single-crystal structure analysis showed the first example of a double helix-like assembly of axially chiral molecules for triphenylamine-modified bis-S,S-dioxide (rac)-DBTOTPA. DBTOTPA also exhibited excellent optical properties, with the maximum quantum yield (ΦPL) reaching 50 % in solution, which could be attributed to the enhanced intramolecular charge transfer (ICT) interactions due to the synergistic action of sulfur oxidation and triphenylamine donor. 1 % DBTOTPA-doped PMMA film also showed a quite high ΦPL value up to 97 %. The (P)- and (M)-enantiomers of DBTOTPA exhibited remarkable orange and deep-red CPL performance in toluene/PMMA film and neat film, respectively, with the luminescence dissymmetry factor (|glum|) of over 1 × 10−3. This work opens a new avenue for designing and synthesizing novel organic CPL emitters with new assembly forms and intensively chiroptical activities. [Display omitted] •Axially chiral D-A-type derivatives were synthesized based on 3,3′-bibenzothiophene and its thienyl-S,S-dioxidized motif.•Their different molecular assemblies in crystals were investigated.•Chiroptical properties of the 3,3′-bi(benzo[b]thiophene-S,S-dioxide) derivative modified by triphenylamine were achieved.