Aggregation-induced enhanced fluorescence by hydrogen bonding in π-conjugated tricarbocycles with a CF₂CF₂-containing cyclohexa-1,3-diene skeleton

Abstract

With our accumulated understanding on CF2CF2-containing organic molecules, we recently achieved synthesis of π-conjugated tricarbocycles with a CF2CF2-containing cyclohexa-1,3-diene skeleton, which was prepared in eight steps from commercially available 4-bromo-3,3,4,4-tetrafluorobut-1-ene....

Diverse Synthetic Transformations Using 4‐Bromo‐3,3,4,4‐tetrafluorobut‐1‐ene and Its Applications in the Preparation of CF2CF2‐Containing Sugars, Liquid Crystals, and Light‐Emitting Materials

“…As tricyclic molecules with various aryl substituents, 69 a – d were selected and synthesized as described in Scheme 13 [50] …”

“…Subsequently, various aromatic Grignard reagents were used to form the corresponding 1,4‐diols 68 . Then, the target tricyclic molecules 69 a – d with a tetrafluorinated cyclohexadiene skeleton at the central position were given through a synthetic method similar to the synthesis scheme of 56 in Scheme 12 [50] …”

“…However, the photoluminescence (PL) of tricyclic molecules 69 a – d was very weak in dilute solutions, in which their PL quantum yield (Φ PL ) was at most 0.31. The low Φ PL is presumed to be caused by molecular motions, such as rotation and vibration, which are non‐radiative deactivation processes in dilute solutions [50] …”

“…In order to examine this dramatic improvement in Φ PL , the X‐ray crystallographic structures of 69 a and 69 c were analyzed (Figures 6c and 6d). [50] …”

“…As tricyclic molecules with various aryl substituents, 69 a-d were selected and synthesized as described in Scheme 13. [50] Scheme 12. Synthetic application to tricyclic molecules having tetrafluorinated carbocycles.…”