Intermolecular interactions boost aggregation induced emission in carbazole Schiff base derivatives

Abstract

Six D-π-A model compounds (compounds 1-6) were conveniently synthesized and characterized by H NMR,C NMR, MS and single crystal X-ray diffraction. One photon absorption and emission properties were studied by using a series of UV-visible and fluorescence spectra and theoretical calculations were applied to investigate the structure-property relationships, which showed that all six compounds possessed an obvious intramolecular charge transfer process which could be attributed to their optical properties. We simultaneously investigated their fluorescence emission performance in water/acetonitrile mixtures and found that they all have outstanding aggregation induced emission properties. Scanning electron microscopy testing illustrated that orderly aggregation was the main reason for their aggregation induced emission properties. Cytotoxicity tests indicated that all these compounds had good biocompatibility for living cells, and bio-imaging studies highlighted the potential application of the six compounds in one-photon fluorescence microscopy imaging domains.

Solvent-Regulated Fluorimetric Differentiation of Al3+ and Zn2+ Using an AIE-Active Single Sensor

“…Then, at a fraction of water higher than 70%, level-off tails were observed in the longer spectral region. Such types of tails are proposed to originate from the Mie scattering effect from the foregoing nanoaggregates/particles in the medium …”

“…Such types of tails are proposed to originate from the Mie scattering effect from the foregoing nanoaggregates/particles in the medium. 54 The free probe H 2 L (20 μM) showed a weak emission intensity maximum at around 505 nm in pure DMSO, but it shifted to 520 nm upon increasing the amount of water (∼90% water content) with a ∼52-fold emission enhancement (Figure 1b). When the water content was further increased, emission maxima shifted toward the right side (∼550 nm); however, the intensity fell down.…”

Mitochondria-Targeted Luminescent Organotin(IV) Complexes: Synthesis, Photophysical Characterization, and Live Cell Imaging

“…Similarly, Schiff bases as fluorescent probes have attracted a great deal of attention as the specific substituents on the ligand moieties change their photophysical properties remarkably. , Schiff bases are a great source of luminescent cell probes because they are low in cytotoxicity, easy to synthesize, noninvasive, and highly photostable. Some specific biomarkers such as coumarin-, diaminomaleonitrile-, salicylaldehyde-, carbazole-, and glucosamine-, Schiff base derivatives have been described previously. Until now, fluorescent Schiff bases , and main-group metals coordinated with Schiff bases − have been used in cell imaging; however, tracking specific organelles such as mitochondria is scarce.…”

Combined Theoretical and Experimental Study on Intramolecular Charge Transfer Processes in Star-Shaped Conjugated Molecules

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