Perylene Bisimide and Naphthyl‐Based Molecular Dyads: Hydrogen Bonds Driving Co‐planarization and Anomalous Temperature‐Response Fluorescence

Abstract

The origin of the positive temperature effect in fluorescence emission of an ewly designed perylene bisimide (PBI) derivative with two naphthyl units containing orthomethoxy group (NM) at its bay positions (PBI-2NM) was elucidated. Akey point is the finding of aweak hydrogen bond (< 5.0 kcal mol À1 )b etween the methoxy group of the NM unit and anearby hydrogen atom of the PBI core.Itisthe bonding that drives co-planarization of the different aromatic units, resulting in delocalization of the p-electrons of the compound as synthesized,i nducing fluorescence quenching via intramolecular charge transfer (ICT). With increasing temperature, the co-planar structure could be distorted in part, resulting in ad ecreased degree of ICT,a nd hence leading to enhanced fluorescence emission. The unique positive temperature effect in emission induced by H-bond-driven co-planarization may pave an ew avenue in designing functional molecular systems complementary to conventional methods.

Excimer Formation of Perylene Bisimide Dyes within Stacking-Restrained Folda-Dimers: Insight into Anomalous Temperature Responsive Dual Fluorescence

“…[11][12][13][14][15] Accordingly, mutual arrangement of the two moieties can be altered via rotation, 16,17 bending 18 and structural reorganization [19][20][21] of the bridge such that various thermally stable configurations may exist, which purportedly exhibit different properties in terms physical or photophysical behaviors. [22][23][24][25] While each above mentioned individual approach has been widely studied, the integration of multiple strategies into a single molecular composite, to our knowledge, has not been fully explored. In a dual moiety featured molecular dyad, the chemical nature of both functional moieties and linkers plays a key role in determining the configurational diversity and hence the associated physical and photophysical properties.…”

Indolylbenzothiadiazoles as highly tunable fluorophores for imaging lipid droplet accumulation in astrocytes and glioblastoma cells

“…As previously reported, this is likely due to strong intramolecular hydrogen-bonding. 25,[34][35][36] Furthermore, the photophysical behavior for the disubstituted analogue 9 differed from 1, even though the calculated torsion angles q were close to zero in all solvents (q ¼ 0.7 -0.9 ). Instead, it followed the trends of compounds bearing electrondonating N-substituents on the indole motif (i.e., 2, 3 and 10).…”

Fluorescence umpolung enables light-up sensing of N-acetyltransferases and nerve agents

“…Unless specially stated, all solvents and chemicals were purchased from commercial suppliers in analytical grade and used without further puri cation. The 1 H and 13 C NMR spectra were recorded on a Bruker AM 400 spectrometer using TMS as an internal standard. The highresolution mass spectrometry data were obtained with a Waters LCT Premier XE spectrometer.…”

“…Intramolecular charge transfer (ICT)-based uorophores 1,2 , featured by donor-π-acceptor (D-π-A) scaffold, are essential research tools in biosensing [3][4][5][6][7] and bioimaging [8][9][10][11][12] . Their exceptionally high sensitivity to the electron disturbance and large Stokes shifts make these chromophores promising platforms for the construction of numerous high-performance uorescent dyes and probes [13][14][15][16][17] . In general, the substitution and/or interaction of the donor receptor with EWTs (which are widespread and found in living organisms and natural environments) can intrinsically suppress the ICT pathway, thereby undesirably quenching the uorescence (Fig.…”