Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• types of CDs and aims to promote the use of these sustainable materials, it opens the way for further exploitation of such compounds in visible-light-catalyzed reactions. UV–vis spectra of the CDs. All the measurements have been performed in water, except for CD-a-GLU, where a H2O/acetonitrile 1:1

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

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

• 1H NMR spectrum. We compared these results to simply estimating the isomer distribution at the PSS (cf. Supporting Information File 1, section 3.1) from the UV–vis spectra and observed good agreement, meaning the results from UV–vis spectroscopy can be used for rough PSD estimation, due to good

• spectral separation of the isomers. Since we encountered fast back isomerization only for NAc-PAP-OH (vide infra), the PSDs could only be determined from the UV–vis spectra. NAc-PAPs showed high to quantitative formation of the Z-configurated isomers. For example, NAc-PAP-Br showed an isomerization

• equipment, experimental procedures, compound characterization, UV–vis spectra at different concentrations, photochemical experiments, thermal isomerization analysis, and NMR spectra. Funding We thank the Swedish Vetenskapsrådet for a Starting Grant (2021-05414 to SC and to 2023-04088 to NAS). This work was

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

• UV–vis 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

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

• 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 UV–vis spectra, a small

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

• well as detailed structure–activity relationships, to optimize massarilactone hemisynthetic derivatives for specific biological applications. Experimental General experimental procedures UV–vis spectra were recorded on a Shimadzu UV/Vis 2450 spectrophotometer. Optical rotations were obtained from an

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

• achieved due to chemical modification of ANTH [25][32]. Changes in the UV–vis 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 UV–vis spectra of ANTH monitored over time showed that new absorbance features began to appear, suggesting the formation of new products. In contrast, the UV–vis spectra of 9,10-ANTH(BnF)2 showed no new absorbance features over time, suggesting that either

• (C8F17)2 [36]. These results make it clear that monitoring photoirradiated solutions by UV–vis spectroscopy must be accompanied by complementary analyses to enable accurate interpretation of the changes in the UV–vis spectra and identification of the photoproducts. The next comparative photostability

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

• 1:1 (v/v) solution which was left to evaporate at room temperature over the course of a few days. Photophysical properties Fluorescence spectra were measured on a Horiba FluoroMax Plus spectrofluorimeter. UV–vis spectra were measured on a Shimadzu UV-1900i UV–vis spectrophotometer. Absorption and

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

• experimental methods Optical rotations at 20 °C were measured with an Anton Paar MCP 150 circular polarimeter (Anton Paar, Graz, Austria). UV–vis 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 UV–vis spectra of the newly described secondary metabolites were assessed in MeOH (Uvasol, Merck, Darmstadt, Germany). Analytical HPLC chromatograms and electrospray ionization mass spectra (ESIMS

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

• separately titrated in order to obtain the UV–vis 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

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• spectra of the products were obtained using an LS45 spectrometer from PerkinElmer. Elemental analyses were conducted using an Vario El CHN mode system from Elementar GmbH. The PL and the UV–vis spectra were obtained using a spectrofluorometer (LS45, PerkinElmer) and a Specord S 600 (Analytik Jena

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• free PyBA. Data analysis, including calculation of the phase transition temperature, was performed using the MicroCal PEAQ-DSC Software. UV–vis absorption measurement UV–vis spectra of DMPC liposomes (1 mM DMPC) with or without catC60 or C60 were measured in PBS(–) using a UV-3600 Plus absorption

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• studies; description of photochemical equipment; characterization data of compounds (1H, 13C and 19F NMR spectra, IR and UV–vis spectra). Acknowledgements The University of Genova is kindly acknowledged for the contribution to the acquisition of an NMR instrument (D.R. 3404 19/7/2018). We thank Mr

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• ), strong (s), medium (m), weak (w) or very weak (vw). UV–vis spectra were recorded on a Cary 60 UV–vis spectrophotometer and emission spectra were recorded on an Agilent Cary Eclipse fluorescence spectrophotometer. Basic and high-resolution mass spectra (MS/HRMS) were measured on instruments coupled to a

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• and cathodic sides became smaller, resulting in a reversible redox wave (Figure 5b). This indicates that the generated DAntM radical rapidly decomposes during the CV measurement, leading to the irreversible redox wave at slow scan rate. The UV–vis spectra of the DAntM radical and cation were shown in

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• parts per million (ppm) and the coupling constants (J) in hertz (Hz). UV–vis spectra were recorded on a Shimadzu UV-2501PC spectrophotometer using DMF as the solvent. The emission spectra were recorded with a Jasco FP-8300 spectrofluorometer using DMF as the solvent. Mass spectra were recorded using a

• consistently displayed the protonated molecular ion [M + H]+ as the base peak. The UV–vis and fluorescence spectra of DPP derivatives 3a–f, 4a, 4d and 4f in DMF are presented in Figure 1, and their photophysical properties are summarized in Table 1. These compounds are highly fluorescent, and their UV–vis

• spectra are very similar. These results indicate that substituents with different functional groups can be attached to DPP 2 without significant modification of their optical properties. The observed Stokes shifts for dyes 3 and 4 averaged in the range of 60–70 nm. All compounds exhibited high

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• assigned using MestreNova. High-resolution mass spectra were obtained on Q-Tof Micro (Waters), equipped with a quadrupole and time-of-flight (TOF) analyser and a multichannel plate (MCP) detector. The melting points were measured on a Boetilus melting point apparatus and are not corrected. UV–vis spectra

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• indicated, are given in Supporting Information File 1. The optical properties of the PAPs were investigated by UV–vis absorption spectroscopy in 10−5 M solutions in CH2Cl2, as depicted in Figure 1. The UV–vis spectra of these compounds exhibited strong absorption in the region of 250–370 nm. These

• 0.1 V/s in 0.1 M [NBu4] [PF6] in MeCN and UV–vis spectra of PAPs in DCM (≈10−5 M). A, B: naphthols 1a,b. C, D: chrysenols 3a–c. E, F: phenanthrols 6a–c. Resonance structures of the phenoxonium cation formed from 2-chrysenol (3a). Formation of phenoxonium cation in the anodic oxidation of phenol

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• three times, until no absorption bands from the host molecules were observed in the UV−vis spectra of washings. The resulting i-SWNTs were analyzed with Raman spectroscopy at 488 nm. The i-SWNTs were bath-sonicated with dithiothreitol (50 mg) in dichloromethane for 30 min followed by filtration with a

• PTFE membrane. This process to remove host molecules was repeated three times, until no absorption bands from the host molecules were observed in the UV−vis spectra of washings. After the resulting p-SWNTs were washed with dichloromethane several times to thoroughly remove all the organic molecules

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• future. Characterization data. (a) FTIR spectra of t-Bu-FIDO and t-Bu-FIDS. (b) UV–vis spectra of fullerene derivatives normalized at 270 nm. (c) Vacuum TGA curves of t-Bu-FIDO (black), t-Bu-FIDS (red), and C60 (blue). The measurements were conducted under 0.1 Pa. (d) HPLC analyses before deposition of t

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• –vis spectra of all polymers were recorded on a PerkinElmer Lambda 365 UV–vis spectrophotometer. FTIR spectra were recorded on an Agilent Cary 630 KBr module. Reaction of aniline with SeO2 To a reaction vessel, 10 mL of acetonitrile were introduced along with aniline (10 mmol, ≈0.91 mL) and selenium

• in Hz. The calibration was done with respect to the signal of residual undeuterated solvent or in relationship to TMS (CDCl3: 1H 7.26 ppm, 13C 77.34 ppm). Single-crystal X–ray diffraction was recorded on a Bruker D8 Quest system. HRESIMS spectra were recorded on a Waters Xevo G2-XS QTof device. UV

Introduction of peripheral nitrogen atoms to cyclo-meta-phenylenes

• Koki Ikemoto and
• Hiroyuki Isobe

Beilstein J. Org. Chem. 2024, 20, 1207–1212, doi:10.3762/bjoc.20.103

• best and afforded cyclic congeners from N3-[6]CMP to N6-[12]CMP (Figure S1, Supporting Information File 1) and isolated N3-[6]CMP (3a) and N4-[8]CMP (3b) in 7% and 3% yields, respectively [14]. Comparisons of the UV–vis spectra of the doped and undoped congeners revealed dopant-induced changes in the

• electronic properties. The UV–vis spectra of 3a and 3b were recorded in chloroform and are shown in Figure 2, with spectra of the undoped [n]CMP congeners shown as references [15]. The nitrogen-doped [n]CMPs 3a and 3b commonly showed minor yet new absorptions at approximately 280 nm, with major absorptions

Kinetically stabilized 1,3-diarylisobenzofurans and the possibility of preparing large, persistent isoacenofurans with unusually small HOMO–LUMO gaps

• Qian Liu and
• Glen P. Miller

Beilstein J. Org. Chem. 2024, 20, 1099–1110, doi:10.3762/bjoc.20.97

• ’-triisopropylphenyl and 2’,4’,6’-tri-tert-butylphenyl substituents are quite similar to each other. Each shows little or no HOMO or LUMO orbital densities on their respective 1,3-diaryl groups indicating greater out-of-plane rotation compared to 3 and modestly larger HOMO–LUMO gaps. The calculated UV–vis spectra for

• at the B3YLP/6-311+G(d,p)//B3YLP/6-31G(d) level using Gaussian 09 [12]. UV–vis spectra calculated for 1,3-diarylisobenzofuran derivatives 1, 2, 3, 23, 24 and 25 using a DFT method performed at the B3YLP/6-311+G(d,p)//B3YLP/6-31G(d) level using Gaussian 09 [12]. UV–vis spectra for the reactions of 2

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

• coupling constants J. Infrared spectra (IR) were measured as attenuated total reflection (ATR) experiments using a Nicolet 380 FT-IR spectrometer. The signals were characterized by their wavenumbers and corresponding absorption as very strong (vs), strong (s), medium (m), weak (w) or very weak (vw). UV–vis

• spectra were recorded on a Cary 60 UV–vis spectrophotometer and emission spectra were recorded on an Agilent Cary Eclipse fluorescence spectrophotometer. Basic and high-resolution mass spectra (MS/HRMS) were measured on instruments coupled to a preceding gas chromatograph (GC) or liquid chromatograph (LC

Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• purified NnlA homologs. All spectra were measured in 100 mM tricine, 100 mM NaCl buffer at pH 7.5. NnlA homolog concentrations were Vs (10 μM), Mr (19 μM), Pd (18 μM), Ms (13 μM), and Ps (4 μM). Inset: Q-band region of the UV–vis spectra for concentrated NnlA homolog samples: Vs (90 μM), Mr (170 μM), Pd