Two-Photon Absorption Properties of Cationic 1,4-Bis(styryl)benzene Derivative and Its Inclusion Complexes with Cyclodextrins

Abstract

Two-photon absorption properties of 1,4-bis{4'-[N,N-bis(6''-trimethylammoniumhexyl)amino]styryl}benzene tetrabromide (C1) and its inclusion complexes (ICs) with cyclodextrins (CDs) have been studied. Upon complexation with CDs, the absorption spectra of C1 showed a slight red shift, whereas the emission spectra showed a blue shift with concomitant increase in the fluorescence quantum efficiency. A Stern-Volmer study using K(3)Fe(CN)(6) as a quencher revealed significant reduction in the photoinduced charge transfer quenching, in accord with the IC formation. Comparison of the spectroscopic results reveals that C1 forms increasingly more stable ICs in the order C1/beta-CD < C1/gamma-CD < C1/(3gamma:beta)-CD (gamma-CD/beta-CD 3:1, mole ratio). Moreover, the two-photon action cross section of C1 increased from 200 GM for C1 to 400 GM for C1/beta-CD, 460 GM for C1/gamma-CD, and 650 GM for C1/(3gamma:beta)-CD, respectively. Furthermore, the two-photon microscopy images of HeLa cells stained with C1 emitted strong two-photon excited fluorescence in the plasma membrane. These results provide a useful guideline for the development of efficient two-photon materials for bioimaging applications.

Cellular internalization of a membrane binding two-photon probe by a complex of anionic diblock copolymer and cationic surfactant

“…TPM using free C1 showed bright emission from the plasma membrane. [12] However, images with encapsulated C1 indicated the localization of C1 to the cytoplasm, suggesting the intracellular uptake of the nanostructure by HeLa cells (Figure 5a). This result indicates that the nanostructure has been internalized into the cells, presumably due to the amphiphilic surface of the vesicle.…”

“…C1 was prepared using the procedure reported previously. [12] The synthesis involved the quaternization of complexes were taken with a micropipette and dropped onto a mica substrate. The solution was allowed to stand for 10 min and then removed gently by air blower and dried for ~20 min at room temperature before taking the images.…”

Steady-State and Femtosecond Transient Absorption Spectroscopy of New Two-Photon Absorbing Fluorene-Containing Quinolizinium Cation Membrane Probes

“…A yellow solid was obtained; yield: 88% (3. 13 Synthesis of 2,8-Bis((E)-2-(7-(diphenylamino)-9,9-dihexyl-9H-fluoren-2-yl)vinyl)quinolizinium hexafluorophosphate (1). 2,8-Dimethylquinolizinium hexafluorophosphate (c) (0.25 g, 0.83 mmol) and 7-(diphenylamino)-9,9-dihexyl-9H-fluorene-2-carbaldehyde (f) (0.87 g, 1.64 mmol) was added piperidine (0.28 g, 3.3 mmol) in acetonitrile (25 mL) and refluxed for 24 h using a Dean−Stark apparatus.…”

“…The pure compound was isolated as a dark red solid; yield: 30% (0.29 g); mp: 130.5−131°C. 1 13 Synthesis of 7-Ethynyl-9,9-dihexyl-N,N-diphenyl-9H-fluoren-2-amine (i). To a solution of 7-bromo-9,9-dihexyl-N,N-diphenyl-9H-fluoren-2-amine (g) (4.00 g; 6.90 mmol) in benzene (30 mL) was added PdCl 2 (PPh 3 ) 2 (0.29 g; 0.42 mmol), CuI (0.13 g; 0.69 mmol), iPr 2 NH (4.20 g; 41 mmol), and trimethylsilyl acetylene (2.14 g; 22 mmol).…”

“…mp: 114°C. 1 13 Synthesis of 2,8-bis((E)-2-(7-((7-(diphenylamino)-9,9-dihexyl-9H-fluoren-2-yl)ethynyl)-9,9-dihexyl-9H-fluoren-2-yl)vinyl)-quinolizinium hexafluorophosphate (2). To a refluxing acetonitrile solution (25 mL) of 2,8-dimethylquinolizinium hexafluorophosphate (c) (0.090 g; 0.30 mmol) and (7-((7-(diphenylamino)-9,9-dihexyl-9H-fluoren-2-yl)ethynyl)-9,9-dihexyl-9H-fluorene-2-carbaldehyde) (j) (0.800 g; 0.90 mmol) was), 4 mL of piperidine was added.…”