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Search for "UV–vis" in Full Text gives 609 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Data accessibility in the chemical sciences: an analysis of recent practice in organic chemistry journals

  • Sally Bloodworth,
  • Cerys Willoughby and
  • Simon J. Coles

Beilstein J. Org. Chem. 2025, 21, 864–876, doi:10.3762/bjoc.21.70

Graphical Abstract
  • about many standard formats [73]. Open formats in NMR, mass spectrometry, UVvis-, IR, and Raman spectroscopy have been recently reviewed [74]. Often a very simple first step is to export coordinate spectroscopic data to CSV, and there are numerous online tools for conversion of proprietary to open file
  • community risks becoming left behind without urgent cultural change. Journal data policies for the study timeframe, 01 February – 31 March 2023. ‘All data’ refers to: spectroscopic data (NMR, IR, UVvis, Raman, circular dichroism and mass spectrometry), chromatography (GC, HPLC, SEC), physical data (m.p
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Published 02 May 2025

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

  • Lewis McGhie,
  • Hannah M. Kortman,
  • Jenna Rumpf,
  • Peter H. Seeberger and
  • John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

Graphical Abstract
  • energy sensitizers, would represent an attractive platform for future reaction design. Here, we disclose the photoactivation of simple alkenylboronic esters established using alkene scrambling as a rapid reaction probe to identify a suitable catalyst and boron motif. Cyclic voltammetry, UVvis analysis
  • solvent had a profound effect on reactivity with more Lewis-basic solvents suppressing reactivity (Table 1, entries 4 and 5 vs entries 6 and 7), indicating p-orbital availability plays a prominent role [56][57]. A control reaction (Table 1, entry 8), in combination with UVvis absorption studies (see
  • details). Conclusion In summary, photoactivation of simple alkenylboronic esters was established using alkene scrambling as a rapid reaction probe to determine the catalyst and boron moiety for sensitization. The use of cyclic voltammetry, UVvis analysis, and control reaction probes support sensitization
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Published 30 Apr 2025

Substituent effects in N-acetylated phenylazopyrazole photoswitches

  • Radek Tovtik,
  • Dennis Marzin,
  • Pia Weigel,
  • Stefano Crespi and
  • Nadja A. Simeth

Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66

Graphical Abstract
  • straightforward development for specific applications. In this work, we synthesized novel N-acylpyrazole-based photoswitches and conducted a comparative study with 33 phenylazopyrazoles, comparing their photoswitching properties and the impact of electronic effects. Using UVvis and NMR spectroscopy, we
  • reported to either bathochromically shift the UVvis absorption spectrum or lead to a better separation of the n→π* bands of the two photoisomers and allow for visible-light-responsive switches [23][24][25][26]. In recent years, heteroaryl azobenzene derivatives have revealed superior properties to
  • bathochromic shift of the n→π* absorption band further moving their UVvis absorption spectrum towards the therapeutic window [35]. Moreover, a similar modification in stilbene-based photoswitches and molecular motors showed an increase in performance and photoisomerization quantum yield [36][37]. Consequently
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Published 25 Apr 2025

Synthesis and photoinduced switching properties of C7-heteroatom containing push–pull norbornadiene derivatives

  • Daniel Krappmann and
  • Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

Graphical Abstract
  • tools, UVvis and NMR spectroscopy were utilized. We determined significant spectral features of the formed NBD species, including λmax and λonset values, all of which exhibit redshifts compared to their isocyclic counterparts. Additionally, the selected QC isomers were subjected to thermal and
  • characterized using UVvis and NMR spectroscopy, as well as high-resolution mass spectrometry. An overview of the synthetic and spectroscopic data for all derivatives is provided in Table 1, while the specific spectroscopic properties of the individual QC analogues can be found in Supporting Information File 1
  • . Photoswitching The photoswitching of the NBDs to corresponding QCs was monitored by UVvis and 1H NMR spectroscopy. With increasing electronegativity of the bridge-atom, a slight bathochromic shift in the absorption spectra of the parent NBD precursors O-NBD1 and N-NBD1 was found (Figure 2a and 2c). For the
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Published 22 Apr 2025

Recent advances in the electrochemical synthesis of organophosphorus compounds

  • Babak Kaboudin,
  • Milad Behroozi,
  • Sepideh Sadighi and
  • Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

Graphical Abstract
  • , the C3-phosphorylated product was also formed. In 2024, Mdluli et al. [67] reported an electrochemical method for synthesizing iminophosphoranes. In this method, iminophosphorane was investigated due to its air stability and the presence of a UVvis chromophore, which enables the analysis of the
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Published 16 Apr 2025

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

  • Leon M. Friedrich and
  • Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

Graphical Abstract
  • UVvis spectra of the two photoswitchable units. This design laid the basis for a robust switching cycle comprising the EManEGlc, the EManZGlc, and the ZManZGlc isomer of 1 [24]. In this contribution, we address the question of how the different isomers of 1 perform as inhibitors of bacterial
  • published tailor-made fitting program [24], the rate constants k1–k4 were extracted from the kinetic traces and are summarized in Table 2. The thermal relaxation of the glycoazobenzene antennas 3, 4, and 5, on the other hand, was monitored by UVvis spectroscopy at 37 °C and the rate constants k5, k6, and
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Published 08 Apr 2025

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

  • Yuuki Ishii,
  • Minoru Yamaji,
  • Fumito Tani,
  • Kenta Goto,
  • Yoshihiro Kubozono and
  • Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

Graphical Abstract
  • . In this study, octafluorinated phenacenes, F8-phenacenes F8PIC, F8FUL, and F87PHEN (see Figure 1 for their chemical structures), were systematically synthesized via the Mallory photoreaction [46] as the key step, and their UVvis and fluorescence spectra were investigated in comparison with those of
  • and fluorescence spectra of F8-phenacenes In order to get insights into the electronic characteristics of F8PIC, F8FUL, and F87PHEN, their UVvis and fluorescence spectra were measured in CHCl3 (Figure 2). The electronic spectra of the corresponding parent phenacenes [48][49] are also illustrated as
  • reference. The selected photophysical parameters are summarized in Table 1. The fluorescence excitation spectra were consistent with absorption spectra to unambiguously assign the fluorescence bands to the studied F8-phenacenes (Figure S1 in Supporting Information File 1). In the UVvis spectra, a small
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Published 24 Mar 2025

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

  • Rémy B. Teponno,
  • Sara R. Noumeur and
  • Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

Graphical Abstract
  • well as detailed structure–activity relationships, to optimize massarilactone hemisynthetic derivatives for specific biological applications. Experimental General experimental procedures UVvis spectra were recorded on a Shimadzu UV/Vis 2450 spectrophotometer. Optical rotations were obtained from an
  • -UV system [column 2.1 × 50 mm, 1.7 μm, C18 Acquity UPLC BEH (Waters), solvent A: H2O + 0.1% formic acid; solvent B: ACN + 0.1% formic acid, gradient: 5% B for 0.5 min, increasing to 100% B in 19.5 min, maintaining 100% B for 5 min, RF = 0.6 mL/min, UVvis detection 200–600 nm]. NMR spectra were
  • ), solvent A: H2O + 0.1% formic acid; solvent B: acetonitrile (ACN) + 0.1% formic acid, gradient: 5% B for 0.5 min, increasing to 100% B in 20 min, maintaining isocratic conditions at 100% B for 10 min, flow = 0.6 mL/min, UVvis detection 190–600 nm]. Preparative HPLC was achieved at room temperature on an
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Published 17 Mar 2025

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

  • Long K. San,
  • Sebastian Balser,
  • Brian J. Reeves,
  • Tyler T. Clikeman,
  • Yu-Sheng Chen,
  • Steven H. Strauss and
  • Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

Graphical Abstract
  • ANTH derivatives with fluorinated substituents (the highest is Φf = 0.97 for 9,10-ANTH(C8F17)2) [25]. Several comparative photostability studies for unsubstituted ANTH and ANTH derivatives using UVvis spectroscopy have been reported, in which the authors studied, if photostability enhancements were
  • achieved due to chemical modification of ANTH [25][32]. Changes in the UVvis spectra were typically used as an indication of the compounds’ decomposition. It is well established that ANTH is rapidly oxidized to form anthraquinone upon exposure to light in the presence of oxygen. Furthermore, endoperoxides
  • irradiated with a 34 W incandescent bulb. The UVvis spectra of ANTH monitored over time showed that new absorbance features began to appear, suggesting the formation of new products. In contrast, the UVvis spectra of 9,10-ANTH(BnF)2 showed no new absorbance features over time, suggesting that either
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Published 07 Mar 2025

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

  • Metodej Dvoracek,
  • Brendan Twamley,
  • Mathias O. Senge and
  • Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

Graphical Abstract
  • ¹H NMR spectra remained unchanged compared to the neat compounds (Figures S1, S3, and S5, Supporting Information File 1), confirming that the reaction occurs selectively in the solid state. Cl2B was also irradiated in DCM with the same 405 nm LEDs, in a quartz fluorescence cuvette. A UVvis spectrum
  • was then taken at time intervals of 15–30 minutes for a total of 3 h. The UVvis monitoring revealed that the absorbance decreases as irradiation continues, indicating photodegradation; however, no evidence of a [2 + 2] cycloaddition product was seen in the spectra (Supporting Information File 1
  • its photophysical properties. While a pure sample of the dimer has not yet been isolated, a UVvis spectrum of Cl2B after 1.75 hours of irradiation in DCM was recorded. The peak corresponding to the remaining monomer was observed, along with a new peak blueshifted by 47 nm compared to the parent
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Published 05 Mar 2025

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

  • Thomas Brandt,
  • Pascal Lentes,
  • Jeremy Rudtke,
  • Michael Hösgen,
  • Christian Näther and
  • Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

Graphical Abstract
  • /data_request/cif. Cambridge CB2 1EZ, UK; fax: +44 1223 336033. Supporting Information File 14: Synthetic procedures, UVvis and NMR switching experiments, copies of UVvis and NMR spectra, and X-ray crystallographic data. Funding The authors thankfully acknowledge financial support by the Deutsche
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Published 04 Mar 2025

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

  • Rita Toshe,
  • Syeda J. Khalid,
  • Blondelle Matio Kemkuignou,
  • Esteban Charria-Girón,
  • Paul Eckhardt,
  • Birthe Sandargo,
  • Kunlapat Nuchthien,
  • J. Jennifer Luangsa-ard,
  • Till Opatz,
  • Hedda Schrey,
  • Sherif S. Ebada and
  • Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

Graphical Abstract
  • ]+ (calculated 446.1962). The UVvis spectrum of 1 (Figure S3, Supporting Information File 1) revealed a prominent absorption peak (λmax) at 434 nm in the visible region reflected by being yellow-colored and suggesting the presence of an extended conjugated π-system in its structure. The 1H NMR and 1H–1H COSY
  • experimental methods Optical rotations at 20 °C were measured with an Anton Paar MCP 150 circular polarimeter (Anton Paar, Graz, Austria). UVvis spectra spanning the 190–600 nm range were acquired using a Shimadzu UV2450 spectrophotometer (Shimadzu, Kyoto, Japan). Electronic circular dichroism (ECD) spectra
  • were obtained using a J-815 spectropolarimeter (JASCO Pfungstadt, Germany). The optical rotation, ECD, and UVvis spectra of the newly described secondary metabolites were assessed in MeOH (Uvasol, Merck, Darmstadt, Germany). Analytical HPLC chromatograms and electrospray ionization mass spectra (ESIMS
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Published 11 Feb 2025

Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity

  • Abel Cárdenas,
  • Zexin Jin,
  • Yong Ni,
  • Jishan Wu,
  • Yan Xia,
  • Francisco Javier Ramírez and
  • Juan Casado

Beilstein J. Org. Chem. 2025, 21, 277–285, doi:10.3762/bjoc.21.20

Graphical Abstract
  • dication is associated to the appearance of a global diatropic ring current which stabilizes the whole molecule. On the contrary, 22+ can be better viewed as two segregated radical cations with slight, but high enough, local diatropic character in each. Here, we use electronic UVvis–NIR absorption and
  • give rise to two naphthylene-centered cations located at both sides of the molecule. The connection path would be partially interrupted by the angular topology, thus accounting for the more similar redox potentials. Electronic spectroscopy The UVvis–NIR electronic absorption spectra of the neutral and
  • +) couple. Electrolyte solutions, at a concentration 0.1 M, were prepared from anhydrous, degassed HPLC grade CH2Cl2 and anhydrous Bu4NPF6. Voltammograms were recorded at a sweep rate of 100 mV s−1. Sample concentrations were ca. 1–2 mM. Electronic spectroscopy UVvis–NIR spectroelectrochemical studies were
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Published 05 Feb 2025

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

  • Islam S. Marae,
  • Jingyun Tan,
  • Rengo Yoshioka,
  • Zakaria Ziadi,
  • Eugene Khaskin,
  • Serhii Vasylevskyi,
  • Ryota Kabe,
  • Xiushang Xu and
  • Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

Graphical Abstract
  • properties were investigated by UVvis absorption and fluorescence spectroscopy in compassion to pristine BPP and its oxidation product, benzo[rst]pentaphene-5,8-dione (BPP-dione). BPP-OiPr exhibited a significantly enhanced photoluminescence quantum yield (PLQY), reaching 73% in comparison to pristine BPP
  • optimized by density functional theory (DFT) calculations (Figure S2 in Supporting Information File 1). The optoelectronic properties of BPP-OiPr 3 and BPP-dione 4 were initially investigated by UVvis absorption spectroscopy in comparison with BPP 2 (Figure 2a). BPP 2 and BPP-OiPr 3 displayed similar and
  • (Figure 2c). In contrast, BPP-dione 4 displayed a considerable redshift of the emission maximum from 538 nm in toluene to 572 nm in dimethylformamide (DMF) along with disappearance of the shoulder peak with increasing solvent polarity (Figure 2d). The UVvis absorption spectra of 4 in different solvents
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Published 04 Feb 2025

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

  • Misato Suganuma,
  • Daichi Kitagawa,
  • Shota Hamatani and
  • Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

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  • by distillation before use. 1H NMR (300 MHz) and 13C NMR (75 MHz) spectra were recorded on a Bruker AV-300N spectrometer with tetramethylsilane (TMS) as the internal standard. High-resolution mass spectra (HRMS) were measured on a JEOL AccTOF LC mass spectrometer. UVvis absorption spectra were
  • solution samples were not degassed. The temperature control for UVvis absorption spectral measurements was carried out using a UNISOKU CoolSpek UV/CD or an Ocean Optics CUV-QPOD. Material Synthesis of compounds N4 and I1–I4 The synthesis of the compounds is shown in Scheme 2. 4-Methyl-5
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Published 31 Jan 2025

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

  • Asahi Kanno,
  • Ryo Tanifuji,
  • Satoshi Yoshida,
  • Sota Sato,
  • Saori Maki-Yonekura,
  • Kiyofumi Takaba,
  • Jungmin Kang,
  • Kensuke Tono,
  • Koji Yonekura and
  • Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

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  • the optical properties of 18 in CHCl3 (c = 100 μM) by measuring its UVvis absorption spectrum as well as its excitation and emission spectra. The UVvis spectrum of 18 showed two absorption peaks at 334 nm and around 375 nm (gray solid line). When excited at 375 nm, the emission spectra of 18
  • - and E- rings serve as hydrogen bond (HB) donors/acceptors to facilitate DNA alkylation at C21. UVvis absorption (gray solid line), the emission spectrum (blue solid line), and the corresponding excitation spectrum (blue dashed line) of the imidate 18 in CHCl3 (c = 100 μM). aQuantum yield (Φfl
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Published 28 Jan 2025

Quantifying the ability of the CF2H group as a hydrogen bond donor

  • Matthew E. Paolella,
  • Daniel S. Honeycutt,
  • Bradley M. Lipka,
  • Jacob M. Goldberg and
  • Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

Graphical Abstract
  • established methods, including 1H NMR-based hydrogen bond acidity determination, UVvis spectroscopy titration with Reichardt's dye, and 1H NMR titration using tri-n-butylphosphine oxide as a hydrogen bond acceptor. Our experiments reveal that the direct attachment of the CF2H group to cationic aromatic
  • as the charge of the solute changes, complicating the Δδ-based direct assessment of HB acidity. To quantify the HB donation ability of both neutral and cationic species on a single scale, we chose an alternative strategy based on an established UVvis spectroscopy titration method [52] with
  • ). Reports in the literature show that the UVvis absorption of the Lewis basic Reichardt’s dye disappears in the presence of some cationic HB donors [52]. We found similar results with 3b and likewise ascribe the unexpectedly small Kd to such limitations of this assay (Figure 3C and Figure S19 in Supporting
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Published 20 Jan 2025

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

  • Pablo Quijano Velasco,
  • Kedar Hippalgaonkar and
  • Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

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  • spectroscopic (e.g., NMR, FTIR, UVvis, Raman) characterization methods are commonly used in real-time reaction monitoring. To quantify the products of a chemical reaction, a calibration curve is required before the optimization campaign. The following sequential steps are typically employed to refine raw data
  • repository to be employed freely for research purposes. In addition to HappyTools, there are other available open-source Python packages to analyze chromatographic and spectroscopic data. A cross-platform Python package named Aston can be used to process both UVvis and MS data. The open-source library is
  • . [70] assembled four complementary PATs, including in-line NMR, UVvis, IR, and online ultra-high-performance liquid chromatography (UHPLC) to meticulously monitor the intricate three-step linear synthesis of the drug mesalazine (18, Figure 7) with a 1.6 g⋅h−1 throughput. In the first step, the
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Published 06 Jan 2025

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

  • Yongming Xiong,
  • Xue Lin Ma,
  • Shilong Su and
  • Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

Graphical Abstract
  • in 3, which consume the energy of the excited state. Figure 4 shows the UVvis absorption spectrum of 3 in cyclohexane with the absorption edge at 561 nm and its emission spectrum with a peak at 580 nm. In the test windows of cyclic voltammetry (Supporting Information File 1, Figure S1), 3 exhibits
  • clarification). Structure of (M,P,M)-3 in the crystal of 3·CH2Cl2 (carbon and oxygen atoms are shown as grey and red ellipsoid at the level of 50% probability, and hexyl groups and hydrogen atoms are removed for clarity). UVvis absorption spectrum (black line) and emission spectrum (blue line, excited at 400
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Published 02 Jan 2025

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

  • Shuxian Qiu,
  • Duan Dong,
  • Jiahui Li,
  • Huiting Wen,
  • Jinpeng Li,
  • Yu Yang,
  • Shengxian Zhai and
  • Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

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  • HRMS spectrometry were in full agreement with the expected structures, and single-crystal X-ray diffraction analysis was conducted to confirm the structure of compound 7-H. Moreover, the photophysical properties of these PhFlOP derivatives were determined by UVvis absorption and photoluminescence
  • CCDC 2256875. The crystallographic details are summarized in Table 1, and the structure of 7-H is shown in Figure 1 as an ORTEP diagram. Photophysical properties In order to investigate the photophysical properties of the PhFlOP-based molecules 7, UVvis absorption and photoluminescence (PL) studies
  • were conducted. UVvis absorption spectra of 7 in toluene solution at room temperature are shown in Figure 2, and the corresponding data are included in Table 2. The spectra in Figure 2a exhibit two major absorption bands at ≈290 nm and ≈340 nm. The band at around 290 nm might be induced by π→π
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Published 30 Dec 2024

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

  • Yang Chen,
  • Jiao He,
  • Hang Lin,
  • Hai-Feng Wang,
  • Ping Hu,
  • Bi-Qin Wang,
  • Ke-Qing Zhao and
  • Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

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  • derivatives and the antiparallel stacking mode into columnar structures stabilized by arene–perfluoroarene intermolecular interactions were confirmed by the single-crystal structure of the alkoxy-free side chain analog, i.e., 1,2,4-trifluoro-3-(perfluorophenyl)triphenylene (F). UVvis absorption and
  • . Photophysical properties: UVvis absorption and photoluminescence UVvis absorption and fluorescence spectra of the synthesized fluorine polycyclic aromatic hydrocarbons Fn and Gnm were measured in solution (in various solvents) and thin film and the results are summarized in Figure 6 and Table S7 in Supporting
  • Information File 1; F6 and G66 were chosen as representative examples. F6 and G66 show almost identical UVvis absorption spectra, both of them possessing a very broad absorption band below 400 nm with two maxima at ca. 380 nm for the strongest peak, and at ca. 360 nm for the smaller one (λabs = 284 nm for
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Published 16 Dec 2024

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

  • Sasha Hayes,
  • Yaoying Lu,
  • Bernd H. A. Rehm and
  • Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

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  • biological profiling. Experimental General experimental procedures Specific rotations were recorded using a JASCO P-1020 polarimeter. UV data was recorded on a JASCO V-650 UVvis spectrophotometer. NMR spectra were recorded at 25 °C on a Bruker Avance III HD 800 MHz NMR spectrometer equipped with a cryoprobe
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Published 09 Dec 2024

Surprising acidity for the methylene of 1,3-indenocorannulenes?

  • Shi Liu,
  • Märt Lõkov,
  • Sofja Tshepelevitsh,
  • Ivo Leito,
  • Kim K. Baldridge and
  • Jay S. Siegel

Beilstein J. Org. Chem. 2024, 20, 3144–3150, doi:10.3762/bjoc.20.260

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  • separately titrated in order to obtain the UVvis spectra of the acids in neutral as well as in deprotonated forms. Then, the same titration is done with a mixture of measured acid (FIC or BFC) and a reference acid. Using the spectral data from the titrations of mixtures the dissociation levels α = [A−]/([A
  • measurements against different reference acids. A Perkin-Elmer Lambda 40 UVvis spectrophotometer connected with optical fibre cables to an external cell compartment inside a MBraun Unilab glovebox filled with 99.999% pure argon was used for the spectrophotometric titrations. This setup ensured that during all
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Published 02 Dec 2024

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

  • Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

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  • increasing addition of TsOH into 67, an increase in electrocatalytic current appeared before the second reduction wave, while the first reduction at −1.14 V remained unchanged, suggesting formation of radical anion [67]˙− as the first step. UVvis spectroelectrochemical measurements under bulk electrolysis
  • the UVvis spectrum revealed a red shift, indicating the presence of diprotonated H4TPP2+ macrocycle (Figure 21a). Fc addition into an air-saturated DCE solution containing 18 (H2TPP) and HTB led to oxidation of Fc to Fc+ and initiated the ORR process (Figure 20b). The rate of ferrocene oxidation (Fc
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Published 27 Nov 2024
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  • ]. Polyrotaxanes were prepared with a coverage ratio of 18, 46, 64, and 71%, and the conjugative polymer without any CD coverage showed a decrease of the UVvis absorption and its broadening at around 40–55 °C than those at 25 °C, while this spectral change became weaker according to the increase of the coverage
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Published 19 Nov 2024
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