Dual Emission and Mechanofluorochromism of a V-Shaped π-System Composed of Disulfonyl-Substituted Dibenzocyclooctatetraenes

Abstract

A series of dibenzocyclooctatetraenes 6 bearing phenylethynyl and phenylsulfonyl groups were synthesized from bromo-substituted formylbenzyl sulfone 4 via cyclic dimerization of 4 and Sonogashira coupling of the resulting dibromocyclooctatetraene 3 with terminal acetylenes. The diamino derivative 6b exhibited dual emission with emission maxima at 436 and 547 nm. Furthermore, in the fluorescence of 6b, solvatofluorochromism was observed in response to solvent polarity, whereas in the solid states, mechanofluorochromism was observed.

Dual emission in purely organic materials for optoelectronic applications

“…Interestingly, LE emission was switched on at higher excitation energy, while the CT emission was accessible at lower excitation energy. 48,49 LE/CT DE has also been observed in purely organic polymers. The simultaneous observation of PL from both LE and CT states in fluorene-dibenzothiophene-S,S-dioxide random copolymer 5 was explained by the competition of the LE emission with the solvent reorganization time at low temperature in polar media.…”

Remarkable Solvatofluorochromism of a [2.2]Paracyclophane‐Containing Organoboron Complex: A Large Stokes Shift Promoted by Excited State Intramolecular Charge Transfer

“…; where ϵ and n are the dielectric constant and reflective index, respectively] versus Stokes shift [ ν ss , Eq. ] of 1 BF 2 and 2 BF 2 were evaluated …”

“…Organicl ight-emitting molecules composed of electron donors (D) anda cceptors (A) usually have an intramolecular charge transfer (ICT) character. [1][2][3][4][5][6] Molecules with ICT character in the excited state have emission properties that are controlled by the surrounding environment. [7][8][9][10] Owing to these unique properties, substances of this type have attracted much attention, especially in the contexto fa pplicationsi no rganic lightemitting diodes [11,12] and sensors.…”

Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes

“…A two‐fold axis of symmetry allows fewer reaction pathways leading to undesired stereoisomers and the dual substitution would contribute configurational integrity to the structure. Despite current interest in dbCOT derivatives, not only in catalysis and catalyst design, but also in areas such as molecular recognition,responsive materials,and light emitting materials,there is a lack of general methods for formation of dbCOTs with this 5,11‐pattern of substitution…”