Search results
Search for "fluorescence emission" in Full Text gives 95 result(s) in Beilstein Journal of Organic Chemistry.
Auxiliary strategy for the general and practical synthesis of diaryliodonium(III) salts with diverse organocarboxylate counterions
Beilstein J. Org. Chem. 2024, 20, 1020–1028, doi:10.3762/bjoc.20.90
- benzoate in 70% yield (Scheme 6A). Furthermore, iodonium salt 7aj with an umbelliferone-3-carboxylate counterion displayed extremely weak blue fluorescence emission under 365 nm UV light compared to free carboxylic acid 6j. This unique property was utilized for tracing the counterion exchange process of
- the diaryliodonium(III) salt by irradiating with 365 nm UV light. The counterion exchange in umbelliferone carboxylate salt 7aj with trifluoroacetic acid was rapid, and after 30 s, the completion of the reaction was confirmed by the emergence of strong blue fluorescence emission due to the liberation
Switchable molecular tweezers: design and applications
Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45
- using a similar principle [24]. The protection from the solvent of the intercalated Pt guest enables its fluorescence emission and is accompanied by the induction of chirality in the resulting host–guest complex. A significant enhancement of the circular dichroism response of the chiral guest is
Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines
Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34
- , angles, and important crystallographic parameters are given in Tables S6 and S7, Supporting Information File 1. Hydrogen atoms are omitted for clarity. a) UV–vis (solid lines) and fluorescence emission (λex = 365 nm, dashed) spectra of compounds 5a–c (toluene, c = 2 10−5 M, l = 1 cm). b) Solutions of
- compounds 5a–c in toluene before irradiation (no emission) and c) during irradiation (photoluminescence, λex = 365 nm) at room temperature. UV–vis (solid lines) and fluorescence emission (dashed, λex = 365 nm) spectra of compounds 6a,b in toluene (c = 2 10−5 M, l = 1 cm) at room temperature. UV–vis
- , fluorescence emission (λex = 500 nm), and fluorescence excitation (λobs = 590 nm) spectra of benzo[5,6][1,4]oxazino[2,3-b]phenothiazine 10c in toluene (c = 2 10−5 M (UV–vis) or c = 2 10−6 M (fluorescence), l = 1 cm) at room temperature. Synthesis of 6,8-di-tert-butyl-N-aryl-3H-phenoxazin-3-imines 3 [6] and 6,8
Biphenylene-containing polycyclic conjugated compounds
Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141
- = 0.07), and compound 64 displayed almost no fluorescence emission (λmax,em = 497 nm, Φem = NA). Naphthazarin–biphenylene hybrid structures Taking the advantage of naphthazarin's bifunctional Diels–Alder reactivity, Swager and his team succeeded in the synthesis of POA-type structures incorporating
A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices
Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122
- energy gap between HOMO/LUMO hybrid orbits and drive fluorescence emission to longer wavelengths [48][49]. In this molecular design, the strong electron-deficient naphtho[2,3-c][1,2,5]thiadiazole (Nz) [13][50][51] as an acceptor and the strong electron-donating carbazole [52] as a donor unit were used in
The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads
Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79
- capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV–vis absorption and fluorescence emission spectra, e.g., in the change of the charge transfer absorption bands. TADF
- by 1H NMR, 13C NMR, and HRMS spectra (Experimental section). UV–vis absorption and fluorescence emission spectra The UV–vis absorption spectra of the compounds were studied (Figure 1 and Figure S29 in Supporting Information File 1). For the compounds without an oxidized PTZ unit, there are
- that affects the fluorescence of these two dyads. Indeed, the highly solvent polarity dependent fluorescence emission intensity, and wavelength are different from the 4-amino NI derivatives, which are much less solvent polarity-dependent [59][61]. Since a TADF molecule is characterized by a stronger
pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene
Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45
- fluorescence emission based on CS-TPE or TBTQ-C6/CS-TPE may find applications in various fields, including the development of visual oral drug delivery systems. Keywords: chitosan; nanoparticle; tetraphenylethylene; tribenzotriquinacene; Introduction Stimuli-responsive assemblies in aqueous media have drawn
- addition, the presence of TBTQ-C6 greatly enhanced the fluorescence emission of the nanoparticles and was able to maintain the fluorescence relatively stable at different pH values. Essentially, this work demonstrates the first study involving stimuli-responsive supramolecular polymeric nanoparticles based
- . The fluorescence properties of CS-TPE and TBTQ-C6/CS-TPE with three different Rf in aqueous medium were investigated by fluorescence spectrophotometry. The fluorescence emission of CS-TPE was significantly enhanced with the increase of its Rf/DL (Figure 7a). This may be caused by the increased
Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme
Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40
- simulations additionally supported the pronounced hypochromic effect (chapter Computational analysis). Fluorescence spectra Fluorescence emission of Phen-Py-1 and Phen-Py-2 measured at pH 5 and pH 7 (cacodylate buffer, Ic = 0.05 mol dm−3) was linearly dependent on the concentration up to 4 × 10−6 mol dm−3
- excimer formation characterized by a new fluorescence emission band at 475 nm, which is significantly red-shifted compared to either fluorescent emission of single phenanthridine (λmax = 400 nm) or pyrene (λmax = 378 and 400 nm) molecule (Supporting Information File 1, Figure S2, left pH 5.0; right pH 7.0
- DNA/RNA polynucleotides [37]. The monomer fluorescence emission at 400 nm was not changed except for titration with poly dGdC–poly dGdC where a small emission increase of emission at 400 nm was observed. At ratios of an excess of polynucleotide over compound (r[compound]/[polynucleotide] < 0.3
CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview
Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29
- showed good fluorescence emission; thus, it could be used as a photodynamic therapy application. In 2013, Liu and colleagues [66] used a click chemistry approach to synthesize meso-tetratriazole-bridged Zn(II) porphyrin-boron dipyrromethane conjugates 164 in 85% yield by reacting porphyrin 146 with
Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence
Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149
- . The synthesis of the dyads is based on the ordinary derivatization of the NI and PTZ chromophores [20]. The molecular structures were confirmed by 1H NMR, 13C NMR, and HRMS methods (Experimental section). UV–vis absorption and fluorescence emission spectra The UV–vis absorption spectra of the
- processes of these dyads upon photoexcitation. Experimental General methods All the chemicals used in synthesis are analytical pure and were used as received without purification. UV–vis absorption spectra were measured on a UV-2550 spectrophotometer (Shimadzu Ltd., Japan). Fluorescence emission spectra
Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups
Beilstein J. Org. Chem. 2022, 18, 1322–1331, doi:10.3762/bjoc.18.137
- prediction of two C2 related, dominating binding sites on 14-3-3ζ that may bind to two of the supramolecular ligand molecules. Keywords: AIE luminophores; fluorescence emission; guanidiniocarbonyl-pyrrole; ligand binding; 14-3-3 protein; Introduction The 14-3-3 protein family was one of the first
- overcome this issue is to use fluorescence emission as a read-out tool, such as an emission “on” or “off” behavior [15]. Selective and sensitive fluorescent ligands have been proven to be essential tools for the study of biological systems by biosensing and imaging [16]. There is an increasing demand for
- , Figures S22–S25). This compound 1 was tested in initial binding assays using fluorescence emission as well as native gel electrophoresis. We could indeed show that 1 binds to 14-3-3ζ as detected by native gel electrophoresis and fluorescence titration (Supporting Information File 1). Experiments show that
Synthesis, optical and electrochemical properties of (D–π)2-type and (D–π)2Ph-type fluorescent dyes
Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106
- band, but also intense fluorescence emission both in solution and the solid state. Keywords: (D–π)2 structure; fluorescence; fluorescent dyes; photoabsorption; redox properties; Introduction The design and development of a new type of organic fluorescent dyes have been of considerable scientific and
- fluorescent dyes constructed of an electron-donating moiety (D) and an electron-withdrawing moiety (A), linked by a π-conjugated unit thanks to their intense photoabsorption and fluorescence emission characteristics originating from the intramolecular charge transfer (ICT) excitation from the D to the A
- photoabsorption band but also intense fluorescence emission both in solution and the solid state, compared to the (D–π)2Ph-type structure. The electrochemical properties of OTK-2 and OTT-2 (0.1 mM) were evaluated using CV in DMF containing 0.1 M tetrabutylammonium perchlorate (Bu4NClO4), in which the potentials
Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products
Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92
- . Fluorescence studies Fluorescence studies of these C-3-substituted pyrido[3,4-b]indole derivatives were examined and various parameters (contact time, concentration and solvent) were optimized for obtaining the best results using 7dA as a model substrate. Fluorescence emission spectra for optimizing the
- . Further, the fluorescence emission profile of 7dA was recorded in chloroform at different concentrations viz. 1 × 10−6 M, 2 × 10−6 M, 3 × 10−6 M, 4 × 10−6 M and 5 × 10−6 M which indicated that fluorescence intensity was found to increase with increase in concentration and fluorescence spectra above this
Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons
Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83
- light, which confirmed that the emission was sensitive to BF3 concentration. Yang et al. used also TFA to shape the fluorescence emission based on the protonation effect between the dissociated H+ and the fluorescent material [32]. Lin et al. used the Lewis acids B(C6F5)3 and AlCl3 to regulate the
Synthesis of a novel aminobenzene-containing hemicucurbituril and its fluorescence spectral properties with ions
Beilstein J. Org. Chem. 2021, 17, 2840–2847, doi:10.3762/bjoc.17.195
- +, and Mn2+ (nitrate salts were used as cation sources) in DMF resulted in different degrees of quenching of the fluorescence emission of host 4. The results are collected in Figure 3 as the corresponding fluorescence quenching efficiency which was quantified using the equation ΔI = (I0 − I), where I is
- halide ions, especially the heavier iodide ion, to the macrocyclic sensor, slightly enhanced the fluorescence emission in CH2Cl2/CH3OH 4:1 (v/v) at 298 K, instead of quenching the fluorescence as predicted by the classic heavy-atom effect. The corresponding fluorescence enhancement efficiency of selected
- −1. In another perspective, the presence of the coordination of selected anions to the macrocyclic sensor enhanced the fluorescence emission in various degree, extremely contrary to the classic heavy-atom effect caused by a heavy atom. In general, this macrocyclic sensor showed high fluorescence
Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases
Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191
- coefficients of the derivatives studied here. All absorption spectra are listed in Supporting Information File 1 (Figures S2–S7). The steady-state fluorescence emission spectra of the Schiff base compounds from their absorption in the UV–vis region was carried out. Derivatives 3aa–fa and 3bb–be were analyzed
- fluorescence yields (Φf) were calculated in order to prove the quantum efficiency of these derivatives in terms of fluorescence emission and thus discuss the influence of the different solvents and substituents. Firstly, by comparing the selected solvents, compound 3aa (R = Ph, R1 = H) presented an emission in
- showing coplanarity of the same system. Normalized absorption spectra in the UV–vis region of compounds (a) 3ea and (b) 3be in CHCl3, MeOH or DMSO solution, respectively ([ ] = 1.50 × 10−5 M). Normalized steady-state fluorescence emission spectra of compound 3aa (R = Ph, R1 = H) in CHCl3 (black solid line
Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation
Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164
- acetylene proton around 4.42 ppm. a) 1H NMR spectrum of chain end modified PCL-Anth; b) UV–vis spectra of (azidomethyl)anthracene (black) and PCL-Anth (red); c) fluorescence emission spectrum of PCL-Anth. a) GPC traces of PS-Az, PCL-Alk and block copolymer (Ps-b-PCL) b) 1H NMR spectrum of the block
Chemical syntheses and salient features of azulene-containing homo- and copolymers
Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139
- displayed fluorescence emission at 385 nm in the protonated state. The electrochemical bandgap of these polymers was in the impressive range of 1.57–1.62 eV. In 2014, Hawker, Robb, and co-workers [35] also reported the synthesis of azulene-fluorene copolymers 117–121, containing varying ratios of 1,3-and
Synthesis of 1-indolyl-3,5,8-substituted γ-carbolines: one-pot solvent-free protocol and biological evaluation
Beilstein J. Org. Chem. 2021, 17, 1453–1463, doi:10.3762/bjoc.17.101
- were obtained from a plot of the semi-logarithmic [conc] vs the intensity of the fluorescence emission, and the IC50 (concentration at which 50% of the enzymatic activity is inhibited) was calculated for the carboline derivatives or doxorubicin using GraphPad Prism, version 7.02 for Windows (GraphPad
Double-headed nucleosides: Synthesis and applications
Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98
Selected peptide-based fluorescent probes for biological applications
Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247
- with nucleic acids. Reprinted with permission from [34]. Copyright (2012) American Chemical Society. A) Molecular structure of peptidic probe 1, Inset: HeLa cells incubated with peptide 1 (50 μM), showing an ATP responsive green fluorescence; B) fluorescence emission spectra of probe 1 (20.0 µM) (λex
- = 410 nm) with increasing concentration (0–10.0 µM) of ATP in 10 mM HEPES buffer, pH 7.4. Reproduced from [39] with permission from The Royal Society of Chemistry. A) Molecular structure of probe 2; B) fluorescence emission spectra for the titration of a 10 μM solution of 2 with p(dA·dT)2 in aqueous
- buffer (pH 7.4) (with base pair/2 molar ratios ranging from 0 to 4.0), inset: nuclei of HeLa cells stained with 2. Reprinted with permission from [34]. Copyright (2012) American Chemical Society. A) Molecular structure of 3; B) fluorescence emission spectra for the titration of a 10 μM solution of 3 with
Incorporation of a metal-mediated base pair into an ATP aptamer – using silver(I) ions to modulate aptamer function
Beilstein J. Org. Chem. 2020, 16, 2870–2879, doi:10.3762/bjoc.16.236
- the fluorescence (Figure 8). The addition of oligonucleotide 1d, which forms one mismatched base pair with 2f close to the fluorescein moiety, leads to hardly any reduction in the fluorescence emission, indicating that 2f binds less effectively (if at all). The oligonucleotide 2q quenches the
- present in the duplex. Except for the system involving the aptamer 1a, none of the systems shows a significant response to AMP in the absence of Ag(I). Unexpectedly, even after the addition of 1 equiv of Ag(I), the fluorescence emission does not significantly increase either. Adding an excess of Ag(I
Encrypting messages with artificial bacterial receptors
Beilstein J. Org. Chem. 2020, 16, 2749–2756, doi:10.3762/bjoc.16.225
- three dyes (Figure 3B), confirmed their presence on the membrane of individual bacteria, as expected from our design (Figure 3, step 1). The images also showed that, in the course of 24 hours, the fluorescence emission generated from the bacterial cells decreased (Figure 3B), as a result of bacterial
Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties
Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189
- ][12][13][14]. Among dyestuffs classes, the push-pull fluorescent dyes are renowned to own such special behaviors. The push-pull dyes generate higher charge delocalization upon excitation, thus enhance both polarizability and fluorescence emission [12][13][14][18]. The charge delocalization upon
The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY
Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188
- with roughly 1 equiv of 1), Dex-1c (ball milling with roughly 0.5 equiv of 1), and Dex-1d (ball milling with roughly 0.1 equiv of 1) expressed as % w/w on the modified dextrans. A) UV–vis absorption and B) fluorescence emission spectra (λexc = 380 nm) of the BODIPY-dextran conjugate Dex-1b solution in
- water. A) Hydrodynamic diameter of (nm) conjugate Dex-1b (at 1 mg/mL in H2O, black curve) and PBS (red curve), respectively. B) TEM image of conjugate Dex-1b in H2O. Fluorescence emission spectra of pyrene (4.4 × 10−8 M) in water and in a water solution in the presence of conjugate Dex-1b. Schematic
Other Beilstein-Institut Open Science Activities
