Non-aromatic annulene-based aggregation-induced emission system via aromaticity reversal process

Abstract

Aggregation-induced emission (AIE) is a photophysical phenomenon correlated closely with the excited-state intramolecular motions. Although AIE has attracted increasing attention due to the significant applications in biomedical and optoelectronics, an in-depth understanding of the excited-state intramolecular motion has yet to be fully developed. Here we found the non-aromatic annulene derivative of cyclooctatetrathiophene shows typical AIE phenomenon in spite of its rotor-free structure. The underlying mechanism is investigated through photoluminescence spectra, time-resolved absorption spectra, theoretical calculations, circular dichroism as well as by pressure-dependent fluorescent spectra etc., which indicate that the aromaticity reversal from ground state to the excited state serves as a driving force for inducing the excited-state intramolecular vibration, leading to the AIE phenomenon. Therefore, aromaticity reversal is demonstrated as a reliable strategy to develop vibrational AIE systems. This work also provides a new viewpoint to understand the excited-state intramolecular motion behavior of lumiongens.

Organic room-temperature phosphorescence from halogen-bonded organic frameworks: hidden electronic effects in rigidified chromophores

“…308(2)Å and both q(C-Br/O) $150 (i.e. 152.40 (9) and 149.21(8)). 38 Reciprocally, each Br atom is interacting with two peri ester groups of a nearby molecule of Br 2 NTE.…”

“…In recent decades, organic phosphorescence has become a more widely explored topic due to the discovery of long-lasting RTP by utilising crystallisation, [6][7][8] aggregation, 9,10 halogen bonding, [11][12][13][14] heavy atoms, 15 and carbonyl substituents [16][17][18] to circumvent the aforementioned issues. [19][20][21][22][23][24][25][26][27][28] Although spin-orbit coupling (SOC) in organic molecules is usually small (on the order of 1 cm À1 , cf.…”

Computational screen-out strategy for electrically pumped organic laser materials

“…All rate constant calculations and mobility calculations are performed via thermal vibration correlation function (TVCF) method in MOMAP 2019B 11 – 13 , which has been successfully applied in a wide range to predict various optoelectrical properties of organic molecules 48 , 49 . During the evaluation of the internal conversion rate constant k ic , we have applied a Lorentzian-type broadening (FWHM = 200 cm −1 ) in time domain when TVCF fails to converge.…”

Recent progress in the molecular imaging of therapeutic monoclonal antibodies

“…Excitingly, due to the aggregation potency, released AIEgens will not diffuse like other small-molecule dyes, minimizing false-positive signals. With a more comprehensive understanding of the emission behaviors of AIEgens, more AIEgens will be available for this strategy [ 99 , 100 ].

Fig.

…”