Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• ) porphyrins were transformed to the corresponding free base and zinc(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins under standard demetallation and zinc insertion conditions. The absorption and emission properties of the obtained porphyrins were investigated by using UV–visible and fluorescence

• ; Zn-TMPP, Soret band at 425 nm) due to the extended π-conjugation after the fusion of the benzo[f]chromeno[2,3-h]quinoxaline moiety at the β-pyrrolic positions of the porphyrin macrocycle. In the fluorescence spectra, free-base benzo[f]chromeno[2,3-h]quinoxalinoporphyrins 9–13 showed emission bands at

• ≈675 nm and 730 nm (Figure 5a). These newly synthesized free-base porphyrins displayed significant red-shifts in their emission spectra in comparison to meso-tetrakis(4-methylphenyl)porphyrin (TMPP; emission bands at ≈652 and 717 nm). Similarly, fluorescence spectra of zinc(II) benzo[f]chromeno[2,3-h

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• when irradiated with UV light. Keywords: 5-aminopyrazole; azlactone; elimination; fluorescence; one-pot synthesis; pyrazolo[3,4-b]pyridin-6-one; Introduction The pyrazolo[3,4-b]pyridine scaffold is present in many biologically active compounds [1][2][3][4][5][6][7][8][9][10][11][12]. Among them, 4

• . We recorded absorption and fluorescence spectra of ethanolic solutions of compounds 4a–i, 9a, and 10a. The emission and absorption spectra of all the compounds differ slightly from each other. Their spectral parameters are presented in Table 2. In the UV spectra of ethanolic solutions of compounds 4a

• -aminopyrazoles 1, 5, 6 and azlactones 2a–i, followed by heating the resulting intermediate in DMSO in the presence of t-BuOK. Photophysical properties of the obtained compounds were studied. Biologically active 4-arylpyrazolo[3,4-b]pyridin-6-ones. Normalized absorption and fluorescence spectra of solutions of

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• a two-photon process. DBU was found to quench the steady-state fluorescence of *PC1 with a quenching rate constant two orders of magnitude smaller than the diffusion rate constant in DMSO at 298 K and one order of magnitude greater under the borylation reaction conditions (i.e., 0.20 M DBU) than the

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• –acceptor dyads were prepared to study the thermally activated delayed fluorescence (TADF) properties of the dyads, from a point of view of detection of the various transient species. The photophysical properties of the dyads were tuned by changing the electron-donating and the electron-withdrawing

• 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

• was observed for the dyads containing the native PTZ unit, and the prompt and delayed fluorescence lifetimes changed with different aryl substituents on the imide part. In polar solvents, no TADF was observed. For the dyads with the PTZ unit oxidized, no TADF was observed as well. Femtosecond

A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• that TMeQ[6] and G form an inclusion complex with a host–guest ratio of 1:1 and the equilibrium association constant (Ka) was 2.494 × 104 M−1. The G@TMeQ[6] fluorescent probe can sensitively recognize Hg2+ ions by fluorescence enhancement. The linear range is 0.33 × 10−5–1.65 × 10−5 mol·L−1, R2

• + ions [34]. Because of the synergistic combination of Q[8], SQ2 and Hg2+ ions, it shows fluorescence quenching. Cong's group found that Q[7] can encapsulate the benzimidazole part of N-(2-benzimidazolylmethyl)-N,N-bis(2-pyridylmethyl)amine cation (BIBPA+) to construct a host–guest fluorescent probe. The

• change in fluorescence intensity can be used for the recognition of Cd2+ and Zn2+ ions [35]. The symmetric tetramethyl cucurbit[6]uril (TMeQ[6]) is one of the earliest characterized modified cucurbit[6]urils [36]. Compared with Q[6], tetramethyl cucurbit[6]uril (TMeQ[6]) has good solubility in water

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• cytometry (BD, USA). CD8+ T cells and Panc02-h7-GP-GFP cells were co-cultured with the corresponding concentrations of compounds or DMSO for 18 h. Fluorescence intensity was measured using a microplate reader (emission at 476 nm, excitation at 514 nm). Anti-inflammatory assay RAW264.7 (a mouse macrophage

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• HPLC. Due to the large conjugated structure, NG 110 exhibited a significantly red-shifted emission in the near-infrared (NIR) region. Furthermore, the structure extension causes significant improvements both in the fluorescence quantum yield and CPL properties. The dissymmetry factors glum of (P)- and

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• of compounds 5d,e and 6d,e is likely a reflection of the elongation of the conjugation chain. This also supports the conjugation pathway between the nitro group and the more distant dimethylamino group of DMAN fragment marked in blue in Figure 7. All synthesized oligomers 5 display no fluorescence in

• solution (chloroform and acetonitrile were tested). For comparison, N,N-dimethyl-4-((4-nitrophenyl)ethynyl)aniline demonstrates a weak fluorescence with an emission maximum at 550 nm (EtOH) [37]. The optical band gaps (Egopt), estimated from the onset point of the absorption spectra, ranged within 2.39 eV

Photocatalytic sequential C–H functionalization expediting acetoxymalonylation of imidazo heterocycles

• Deepak Singh,
• Shyamal Pramanik and
• Soumitra Maity

Beilstein J. Org. Chem. 2023, 19, 666–673, doi:10.3762/bjoc.19.48

• ]. Finally, the reaction of 5 with benzoic acid and zinc acetate (in a 1:1 ratio) under standard reaction protocol resulted in the competitive formation of products 4a and 10 (Scheme 3E), indicating the susceptibility of other acids towards this method. These results, along with the Stern–Volmer fluorescence

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• in the presence of TBTQ-C6 was greatly improved. In addition, the fluorescence of CS-TPE was significantly enhanced by introducing TBTQ-C6, and remained relatively stable with variations in pH for both CS-TPE and TBTQ-C6/CS-TPE. Such pH-responsive supramolecular spherical nanoparticles with stable

• 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

• , conventional fluorescent dyes exhibit aggregation-caused quenching (ACQ) when introduced into nanoparticles at high loads, resulting in poor fluorescence imaging quality. In recent years, tetraphenylethylene (TPE)-based dyes have been frequently used to overcome the ACQ problem due to their unique aggregation

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• a pH-dependent excimer formation that is significantly red-shifted relative to the pyrene and phenanthridine fluorescence. While the conjugate with a short linker showed negligible spectrophotometric changes due to the polynucleotide addition, the conjugate with a longer and more flexible linker

• exhibited a micromolar and submicromolar binding affinity for ds-polynucleotides and inactivated a mutant of dipeptidyl peptidase enzyme E451A. Confocal microscopy revealed that the conjugate with the longer linker entered the HeLa cell membranes and blue fluorescence was visualized as the dye accumulated

• signalize complex formation (interaction with a biomolecule, cyclodextrine, metal cation, etc.) or change of receptor conformation [5][6]. Employment of pyrene as a biosensor is complicated due to its large aromatic surface's hydrophobicity and fluorescence sensitivity to oxygen. Therefore, modifications of

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• fluorescence spectra. Synthesis of meso-triazole-bridged porphyrin conjugates In recent years, many chromophoric moieties have been introduced at the meso-position of porphyrins by implying diverse synthetic procedures. Among these, the CuAAC click-mediated reactions are proving to be a popular choice for the

• a photophysical investigation, a weak interaction was observed between two subunits at ground state in porphyrin-ferrocene dyads. Also, the fluorescence of porphyrin was significantly quenched in porphyrin-ferrocene conjugates due to photoinduced electron transfer from ferrocene to porphyrin

• protocol in a 42% yield by using CuI and DIPEA in THF at room temperature (Scheme 11). Their photophysical studies revealed that the fluorescence of zinc porphyrin 58 is strongly quenched due to the copper-corrole 59 in the dyad 60. Also, an efficient excited-state interaction was found between zinc

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• visualized by their fluorescence under UV–lamp (λ = 245 and 365 nm) or staining with iodine vapor or 15% H2SO4 or KMnO4 solution, or Ce(IV)SO4 in H2SO4. Melting points were determined on a Gallenkamp apparatus UK and are uncorrected. NMR spectra were recorded on a Bruker 600 MHz spectrometer at the central

Formal total synthesis of macarpine via a Au(I)-catalyzed 6-endo-dig cycloisomerization strategy

• Jiayue Fu,
• Bingbing Li,
• Zefang Zhou,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2022, 18, 1589–1595, doi:10.3762/bjoc.18.169

• -inflammatory [4][5][6][7][8], insecticidal, fungicidal, etc [9]. In addition to the above-mentioned activities, macarpine was also used as a DNA probe for flow cytometry and fluorescence microscopy due to its fluorescent properties [10]. Despite some research on the activities of macarpine had been performed

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• pyrene to form the exciplex dimer that fluoresces in the red region of the spectrum and does not self-quench. A fluorescence microscope was then used to take an image of the array, and the image used to quantify the fluorescence, and thereby the amount of material present, at each region of the array

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

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• investigate the joint influence of the conformation flexibility and the matching of the energies of the charge-transfer (CT) and the localized triplet excited (3LE) states on the thermally activated delayed fluorescence (TADF) in electron donor–acceptor molecules, a series of compact electron donor–acceptor

• : charge-transfer; electron donor; intersystem crossing; TADF; triplet state; Introduction Thermally activated delayed fluorescence (TADF) has attracted much attention in recent years, not only for its application in organic light emitting diodes (OLED) [1][2][3] but also as a mean for studying of charge

• . 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

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

• Sanaz Ahmadipour,
• Alice J. C. Wahart,
• Jonathan P. Dolan,
• Laura Beswick,
• Chris S. Hawes,
• Robert A. Field and
• Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

• Asp260 & Asp109 in coordination with Mg2+ and two water molecules in close proximity to C6 [16]. Evaluation of GDP 6-chloro-6-deoxy-ᴅ-mannose against GMD GMD from P. aeruginosa was co-incubated with GDP-mannose 1 and sugar nucleotide 19, and the production of NADH monitored by fluorescence (excitation

• 355 nm; emission 460 nm). Figure 3 illustrates a reduced rate of NADH production by GMD upon incubation with both probe 19 and the native substrate 1 (blue line). No significant increase in fluorescence was observed upon incubation of probe 19 and GMD (green line). However, a moderate level of NADH

• production was restored upon spiking the incubation with GDP-Man 1 after 85 minutes. The rate of fluorescence increase was reduced compared to both the positive control and incubation with 19 and 1 (Figure 3, blue line). This suggests that 19 may bind to GMD, but not as a substrate. Furthermore, we extended

Computational model predicts protein binding sites of a luminescent ligand equipped with guanidiniocarbonyl-pyrrole groups

• Neda Rafieiolhosseini,
• Matthias Killa,
• Thorben Neumann,
• Niklas Tötsch,
• Jean-Noël Grad,
• Alexander Höing,
• Thies Dirksmeyer,
• Jochen Niemeyer,
• Christian Ottmann,
• Shirley K. Knauer,
• Michael Giese,
• Jens Voskuhl and
• Daniel Hoffmann

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

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• fluorescence; Introduction Light-emitting electrochemical cells (LEECs) are thin film light-emitting devices typically consisting of an emissive layer containing ionic species that facilitate charge transport and an emissive semiconductor material. The emissive layer is sandwiched between two air-stable

• -radiative decay due to the energy gap law (ΦPL = 11% and 7% under vacuum and in air, respectively) in MeCN [37]. The S1 and T1 levels were measured from the onsets of fluorescence (2.66 eV) and phosphorescence spectra (2.41 eV) in 2-MeTHF glass at 77 K (Figure S26, Supporting Information File 1). DiKTa

• emission in the neat film was also observed for DiKTa (ΦPL = 11%, under N2) [27]. The S1 and T1 levels were measured from the onsets of fluorescence and phosphorescence spectra in the 1 wt % doped mCP film at 77 K (Figure S29 in Supporting Information File 1). The corresponding ΔEST values are 0.20 eV and

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• thermally activated delayed fluorescence (TADF) characteristics are emerging due to the potential applications in optoelectronic devices, time-resolved luminescence imaging, and solid-phase sensing. Herein, we synthesized two (4-bromobenzoyl)pyridine (BPy)-based donor–acceptor (D–A) compounds with varying

• aggregated state as compared to toluene solution. Consequently, a faster reverse intersystem crossing rate (kRISC) was obtained in the aggregated state, facilitating photon upconversion, leading to enhanced delayed fluorescence. Further, the lone-pair electrons of the pyridinyl nitrogen atom were found to be

• sensitive to acidic protons. Hence, the exposure to acid and base vapors using trifluoroacetic acid (TFA) and triethylamine (TEA) led to solid-phase fluorescence switching with fatigue resistance. The current study demonstrates the role of the donor strength and size in tuning ΔEST in the aggregated state

Scope of tetrazolo[1,5-a]quinoxalines in CuAAC reactions for the synthesis of triazoloquinoxalines, imidazoloquinoxalines, and rhenium complexes thereof

• Laura Holzhauer,
• Chloé Liagre,
• Olaf Fuhr,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2022, 18, 1088–1099, doi:10.3762/bjoc.18.111

• -diisopropylethylamine; OLED, organic-light emitting diode; SCE, saturated calomel electrode; TADF, thermally activated delayed fluorescence; TEMPO, 2,2,6,6-tetramethylpiperidinyloxyl; TIQ, triazoloimidazoquinoxaline. UV–vis absorption spectra of the obtained metal complexes (18 µM solutions) in acetonitrile at 20 °C

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• stannyl D–π unit with 1,3-diiodobenzene, respectively. Their optical and electrochemical properties were investigated by photoabsorption and fluorescence spectroscopy, time-resolved fluorescence spectroscopy, cyclic voltammetry (CV) and molecular orbital (MO) calculations. In toluene the photoabsorption

• and fluorescence maximum wavelengths (λmax,abs and λmax,fl) of OTT-2 appear in a longer wavelength region than those of OTK-2. The fluorescence quantum yield (Φfl) of OTT-2 is 0.41, which is higher than that (Φfl = 0.36) of OTK-2. In the solid state OTT-2 shows relatively intense fluorescence

• properties (Φfl-solid = 0.24 nm), compared with OTK-2 (Φfl-solid = 0.15 nm). CV results demonstrated that OTT-2 and OTK-2 exhibit a reversible oxidation wave. Based on photoabsorption, fluorescence spectroscopy and CV for the two dyes, it was found that the lowest unoccupied molecular orbital (LUMO) energy

Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• and substituents was also studied during investigation of fluorescence properties of these derivatives. Keywords: β-carboline; DABCO; fluorescence; MBH reaction; Michael addition; structure–fluorescence activity relationship; Introduction Among the polycyclic alkaloids based on indole, the tricyclic

• by evaluation of their fluorescence properties. Results and Discussion The current study began with the synthesis of substituted 3-formyl-9H-β-carbolines (6a–e), which was accomplished by modifying the previously disclosed process as presented in Scheme 1 [46][47][57]. Pictet–Spengler (P-S

• . 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

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• ; fluorescence; Lewis acid; Lewis base; post-synthesis; Introduction Organic light emitting diodes (OLEDs) show great potential to dominate the next generation of flat-panel displays and efficient light sources attributed to the advantages of self-illumination, high efficiency, wide color gamut, and flexibility

• 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

• 7 in Figure 5), which consisted of the twisted A–π–D–π–A structure with N-(4-aminophenyl)carbazole (CzPA) as electron donor unit, pyridine as electron acceptor unit, and 9,9-dioctylfluorene (F) as π-conjugated linker [32]. Compound 7 showed remarkable dual-fluorescence properties when mixed with a