Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• photophysical properties is displayed in Figure 4. Corresponding photophysical data and quantum yields are described in Table 2. The analysis of the absorption spectra revealed that the spectra can be divided into a short-wave and long-wave region. In the long wavelength region (350–500 nm) all measured

• observed, despite the presence of the π-donor group at the same position. However, a shoulder on the emission peak was observed, which may indicate the influence of the double bond. Finally, the quantum yields of all compounds were determined and compared. Compound 5f afforded the highest quantum yield

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• cells (l = 1 cm, V = 2 mL). Fluorescence quantum yields were determined relatively to (Z)-N-((3-oxobenzo[b]thiophen-2(3H)-ylidene)methyl)-N-phenylacetamide as a standard (φfl = 0.16 ± 0.005) [14][33]. Stock solutions of compounds 2a–c (c 1.0 × 10–4 mol⋅L−1) and metal perchlorates (c 2.0 × 10–4 mol⋅L−1

• , and quantum yields of the 2a–c→3a–c rearrangementa. Supporting Information Supporting Information File 26: Experimental procedures and characterization data for all new compounds 1, 2a–c and 3a–c. Supporting Information File 27: 1H and 13C NMR, IR and HRMS spectra of all novel compounds. Supporting

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• the reaction of A ↔ B using experimental absorption spectra of the initial form A and two photostationary states (PSS) obtained at two different wavelengths [48]. In 1968, Ross and Blanc for the first time applied the Fischer method to calculate the extinction coefficients and quantum yields of the

• nm laser, compound 17a exhibited pronounced negative photochromism. The thermal backward reaction occurred within 120 min in the dark in acetonitrile. The photoisomerization quantum yields for compounds 17a (φZ→E = 0.13, φE→Z = 0.46), 17b (φZ→E = 0.01, φE→Z = 0.02), and 17c (φZ→E = 0.06, φE→Z = 0.20

• the photoreaction, is advantageous for applications in bulk materials because the photoisomers have decreased absorbance at the excitation wavelength [9]. Depending on the substitution pattern, the quantum yields for the E–Z photoisomerization of indigo photochromes vary from 0.001 to 0.46 and the

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• , 639, and 594 nm, with fluorescence quantum yields of 6.1%, 7.5%, 1.6%, and 7.8%, respectively, when dissolved in cyclohexane. Notably, the photoluminescence characteristics of these compounds depend on the solvent polarities, as evidenced by the observed decrease in the fluorescence quantum yields in

• broad emission spectra encompassing the entire visible region, featuring two peaks centered at 430–472 and 633 nm. The fluorescence quantum yields estimated for 73, 74, and 75 in acetonitrile are 3.4%, 3.3%, and 4.3%, respectively. Notably, in the case of 74 and 75, the intensity of the long-wavelength

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• the solutions of the compounds showed non-structured emission peaks in the visible region, which are attributed to ICT emission. The PL intensities of the solutions of the compounds are enhanced after deoxygenation, which is indicative of TADF. The photoluminescence quantum yields and TADF properties

• groups to achieve optimal charge-transporting and fluorescent properties within one TADF compound (Figure 1) [5]. The obtained TADF emitters (453 to 550 nm) show photoluminescence quantum yields of up to 98% in oxygen-free toluene solutions. These TADF emitters are suitable for OLEDs with brightness of

• nm, further allowing us to analyze the luminescence dynamics in detail. To determine photoluminescence quantum yields (PLQY), a dedicated integrated sphere with an inner diameter of 120 mm was used in conjunction with the Edinburgh Instruments FLS980 spectrometer. This specialized setup enabled

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• absorption and emission maxima of 411 and 520 nm, respectively, with a mega Stokes shift of 109 nm and fluorescence quantum yields both in the solid state (41%) and in solution (86%). The optical properties were supported by computational chemistry using density functional theory for optimized geometry and

• Horiba, FL3-2IHR fluorescence spectrophotometer. Solid-state and solution-state quantum yields were measured using a Hamamatsu Quantaurus-QY Absolute PL Quantum Yield Spectrometer. Thermal gravimetric analysis (TGA) was performed on a PerkinElmer Diamond TA/TGA with a heating rate of 10 °C min−1 under

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• [11], laser dyes [12], and DR/NIR electroluminescent devices [13][14][15][16][17][18]. However, DR/NIR chromophores typically suffer from low photoluminescent quantum yields (PLQY) because of their intrinsic small band-gap energy causing larger vibronic coupling between the ground and excited states

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• revealed a distorted ruffled molecule with a macrocycle incorporating a pyrroloindole subunit formed through the fusion between the para-phenylene ring and the pyrrolic nitrogen. 42 demonstrated fluorophore behaviour with relatively large fluorescence quantum yields of 10–20% and singlet state lifetimes of

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• compete with classic phosphorescent emitters that employ scarce metals such as iridium and platinum [7][8][9]. Since its first report in 2012 by Uoyama et al., 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) has been a benchmark TADF emitter due to its high quantum yields and excellent

• is up to 0.4 eV higher in energy than the singlet 1CT state. The high quantum yields of up to 46% indicate that the yellow-green 4BGIPN emitter shows a high promise as a platform for developing bright 4BGIPN-TADF class III type compounds with unity PLQY. Future works may benefit in isolating a

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

• data of all compounds are compiled in Table 1. The fluorescence quantum yields (ΦF) of the compounds were measured with an optical integration sphere and were in the range of 2–4% for the dyads with PTZ unoxidized and oxidized. It is interesting to note that the fluorescence quantum yields of the dyads

• Ltd., U.K.). Fluorescence quantum yields (ΦF) were measured by an absolute photoluminescence quantum yield spectrometer (Quantaurus-QY Plus C13534-11, Hamamatsu Ltd., Japan). Luminescence lifetimes of compounds were measured with an OB920 luminescence lifetime spectrometer (Edinburgh Instruments Ltd

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 suggested four main peaks were detected, belonging to two pairs of enantiomers. Notably, one pair of enantiomers can transform to the thermodynamically more stable (M,M,P)-91 and (P,P,M)-91 enantiomers after 16 hours heating. Compared to structures 82 and 86, the photoluminescence quantum yields

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

• . (Figure S3, Supporting Information File 1). Emission quantum yields in acidic and neutral water solutions for Phen-Py-1 are given in Table 1. Excitation spectra of conjugates Phen-Py-1 and Phen-Py-2 were in good agreement with their UV–vis spectra. Phenanthridine–pyrene conjugate Phen-Py-1 exhibited

• measured on a Varian Cary 100 Bio spectrometer. Fluorescence spectra were recorded on a Varian Cary Eclipse fluorimeter. CD spectra were recorded on JASCO J815 spectrophotometer. Absolute quantum yields (Φf) were determined using software implemented with the instrument by the Integrating sphere SC-30 of

• the Edinburgh FS5 spectrometer. Quantum yields were measured for argon-purged solutions in sodium cacodylate buffer, pH 7.0, I = 0.05 mol dm−3, or pH 7.0, Ic = 0.05 mol dm−3 (λexc= 280 nm) at room temperature (25 °C) in a quartz cuvette of 10 mm path length; to avoid the scattering of incident light

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

• -Ph-PTZ, NI-PhMe2-PTZ, and NI-3Br are 432 ms (Figure S30a, Supporting Information File 1), 376 ms (Figure S30b), and 4 ms (Figure S30c), respectively. The photophysical properties of all compounds are compiled in Table 1. The fluorescence quantum yields of the dyads (1.0% to ≈4.5%) are generally much

• lower than those of the amino-NI derivatives (60% to ≈70%) [20]. In order to have a preliminary evaluation of the ISC of the compounds, the singlet oxygen quantum yields (ΦΔ) were studied in several solvents (Table 1 and Table 2). For NI-PTZ, ΦΔ is high in HEX (19%), which is similar to the value

• were recorded with an FS5 spectrofluorometer (Edinburgh instruments Ltd., U.K.). Fluorescence quantum yields (ΦF) were measured by an absolute photoluminescence quantum yield spectrometer (Quantaurus-QY Plus C13534-11, Hamamatsu Ltd., Japan). Luminescence lifetimes of compounds were recorded with an

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

• films, both emitters showed good photoluminescence quantum yields of 71% and 61%, and delayed lifetimes of 316.6 μs and 241.7 μs, respectively, for DiKTa-OBuIm and DiKTa-DPA-OBuIm, leading to reverse intersystem crossing rates of 2.85 × 103 s−1 and 3.04 × 103 s−1. Light-emitting electrochemical cells

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

• moiety [4][5][6][7][8][9][18][19][20][25][26]. Furthermore, the (D–π–)2A-type fluorescent dyes with two D–π moieties have recently been stimulating intensive research efforts because of their high molar extinction coefficients and fluorescence quantum yields, compared to those of D–π–A-type fluorescent

• state, the photoabsorption and fluorescence maximum wavelengths of OTT-2 appear in a longer wavelength region than those of OTK-2, and the fluorescence quantum yields of OTT-2 are higher than those of OTK-2. The cyclic voltammograms demonstrated that OTT-2 and OTK-2 exhibit a reversible oxidation wave

• sphere system. Fluorescence spectra of solutions and solids were measured with a HORIBA FluoroMax-4 spectrofluorometer. Fluorescence quantum yields in solution and in the solid state were determined using a HORIBA FluoroMax-4 spectrofluorometer with a calibrated integrating sphere system. Fluorescence

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• other hand, DBC-H, DBC-Me, and DBC-Si showed relatively strong photoluminescences with quantum yields of 28%, 21%, and 11%, respectively (Table 3). The photoluminescence wavelengths were shifted toward longer wavelengths in the order of DBC-Si, DBC-H, DBC-Me, DBC-SMe, and DBC-S(O)2Me. Of these, the

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• solutions of DH-1 and DH-2 in CHCl3/CH3OH 5:1 (v/v) were employed for growing single crystals. The fluorescence quantum yields (ΦF) of DH-1–3 are characterized in dichloromethane with quinine sulfate in 0.1 N H2SO4 as the control. Synthesis of 5a–c and DH-1–3 Synthesis of 1,3-bis(2-(5-(trimethylsilyl

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• excitation maxima (Exmax), emission maxima (Emmax), and fluorescence quantum yields (Φ) of the molecules from fluorescence spectroscopic studies. The pyrido[1,2-a]pyrrolo[3,4-d]pyrimidine derivatives 3a,b possessing a highly complex ring-fused system emitted fluorescence at 545–546 nm and 537–538 nm in

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• by a Lambda 950 UV–vis–NIR spectrometer (Perkin Elmer). The fluorescence quantum yields (ΦF) in ambient air were estimated by the integrating sphere method [49] in integrating sphere (Sphere Optics) coupled to a CCD spectrometer PMA-12 (Hamamatsu) via optical fibers excited with a CW xenon lamp. ΦPF

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• present high photoluminescence quantum yields, ΦPL, of 75.2% and 71.9%, respectively, and delayed fluorescence lifetimes, τd, of 25.48 μs and 34.31 μs, respectively. The devices produced with these materials reached maximum external quantum efficiencies (EQEmax) values of 14.5% and 30% at low brightness

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• absorption spectra were measured in diluted dichloromethane solutions (c = 1 × 10−5 M) at room temperature. Table 2 summarizes the obtained spectral data, fluorescence quantum yields, stokes shifts, and optical band gap energies. As shown in Figure 2, most of the compounds show a broad band at around 320–360

• methoxy substituent in para-position, gave the highest value of 5770 cm−1. The fluorescence quantum yields of 4a–d were calculated with a comparative method, where quinine sulfate (SQ) in 0.1 M H2SO4 was used as standard [66]. The fluorescence and absorbance spectra for quinine sulfate and product 4b are

• commercially available anthranilic acid. Their photophysical properties show an impact of the aryl substituents on absorption and fluorescence. Methoxy substituents lead to a red shift of the emission and exhibited the highest fluorescence quantum yields. According to the theoretical studies, all products

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• of tetrahydroacridines have, to the best of our knowledge, not been studied so far. Recently, our research group reported the synthesis of a large variety of acridine derivatives which showed promising fluorescence properties and high quantum yields [58][59][60]. In continuation of our previous

• methoxy substituent exhibits a larger red shift of around 40 nm. Based on the absorption and emission spectra, the prepared tetrahydroacridine derivatives possess stokes shifts (wavenumber) ranging from 2400 to 4300 cm−1. Their fluorescence quantum yields range from 0.1 to 0.2 as measured according to a

Synthesis of 10-O-aryl-substituted berberine derivatives by Chan–Evans–Lam coupling and investigation of their DNA-binding properties

• Peter Jonas Wickhorst,
• Mathilda Blachnik,
• Denisa Lagumdzija and
• Heiko Ihmels

Beilstein J. Org. Chem. 2021, 17, 991–1000, doi:10.3762/bjoc.17.81

• , it has been found that berberine (1a) exhibits a selective cytotoxicity against cancer cells [12][13], which is mainly based on its DNA-binding properties [14]. Since the complexation with DNA leads to significant changes of the fluorescent quantum yields of the bound berberine, it can also be used

• low fluorescence quantum yields are caused by conformational changes in the excited state, the fluorescence was recorded in media with different viscosity, namely in glycerol at different temperatures (Figure 2, Figure S2, Supporting Information File 1). It was observed that the derivatives 5a–e have

• significantly higher, but still relatively low emission quantum yields in glycerol at room temperature (Φfl = 0.009–0.031, 20 °C, η = 1412 cP) [41], whereas the emission intensity decreased with increasing temperature (Φfl = 0.001–0.002, 80 °C, η = 32 cP) [41]. Such a behavior usually indicates a radiationless