Multiwavelength anti-kasha's rule emission on self-assembly of azulene-functionalized persulfurated arene

Organic emitters that can give birth to emission from highly excited states have been of unique interest currently, whereas ways to strengthen the so-called anti-Kasha's rule emission at the chemistry level are still limited. Since the appearance and improvement of this emission pathway connects to the special potential of avoiding additional consumption from internal conversions and other forms of electronic relaxation processes, we here report the synthesis and photophysical study of a molecular structure consisting of cyanostyryl-modified azulene and hexathiobenzene core to exhibit a largely enhanced multiwavelength anti-Kasha's rule luminescence. Such an emission pathway in this compound can be effectively tuned and strengthened in response to the aggregation-induced emission effect as well as the fluorescence resonance energy transfer process, which totally allow a ca. 15-fold amplification of the quantum yield of this material as compared to the routine precursors. Moreover, the luminescence in this system can also be smartly regulated by many factors including protonation, light irradiation, and solution type. Enhanced emission can be maintained in the dye-doped polymer film, providing new visions for the development of advanced solid-state emissive materials.