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

Synthesis and characterization of water-soluble C₆₀–peptide conjugates

• Yue Ma,
• Lorenzo Persi and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71

• , PDI): 5a: 4.8 (0.757), 5b: 3974 (0.906), 5c (crude): 1382 (0.115) in Milli-Q® water and 5b: 11.8 (1.000) in pH 9.0 TRIS buffer. Milli-Q® water was pH 7.0. UV–vis spectra of C60–peptide conjugates 5a and 5b (20 μM in Milli-Q® water for 5a and in pH 9.0 TRIS buffer for 5b). 1H NMR spectrum of C60

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• recorded on a Varian Excalibur 3100 FTIR instrument using the attenuated total internal reflection technique (ZnSe crystal). UV–vis spectra were recorded at c = 2⋅10−5 M in toluene solutions with a Varian Cary 100 spectrophotometer. Photoluminescent spectra were recorded at c = 2⋅10−5 M (compounds 5a–c and

• , Supporting Information File 1. Thermal ellipsoids are drawn at the 50% probability level. UV–vis spectra of 6,8-di-tert-butyl-2-(arylamino)-3H-phenoxazin-3-ones 4a–h (toluene, c = 2⋅10−5 M, l = 1 cm, T = 293 K). Molecular structure of ethyl 2,4-di-tert-butyl-14H-quinoxalino[2,3-b]phenoxazine-10-carboxylate

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

• Chuan Yang,
• Wei Shi,
• Jian Tian,
• Lin Guo,
• Yating Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

• EDA charge transfer complex because there was no obvious EDA charge transfer band in the UV–vis spectra (Figure 2). Their indole substrate was more electron-rich in structure. The quantum yield was measured to investigate whether there was a radical chain process or not. The procedure was following a

• derivatives. UV–vis spectra of substrates; [1a] 0.33 M, [2a] 0.11 M. Selected works for the construction of dihydropyrido[1,2-a]indolones and current methodology. Substrate scope of the cascade reaction. Radical trapping experiment. Plausible reaction mechanism. Optimization of reaction conditions.a

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• spectrometer and are referenced to tetramethylsilane (1H, 13C), and 85% H3PO4 (31P). Deuterated solvents were obtained from Cambridge Isotope Laboratories Inc. UV–vis spectra were recorded on an Agilent Cary 60 UV–vis spectrophotometer. Kinetic evaluation was conducted assuming a second-order reaction as

• molecular structures of 2a (orange) and 2f (blue); c) bond length of the phenolate substituent for 2a, 2f and 2,4-di-tert-butyl-6-(triphenylphosphonium)phenolate [30]; d) resonance structures for the description of the bonding situation in 2a. Left: UV–vis spectra of 2a, 2b and 2d in chloroform (straight

• 30: Experimental procedures, plot of the solid-state structure of 2f, crystallographic data, NMR spectra, UV–vis spectra and experimental and simulated time conversion plots for the zwitterion formation. Funding Funding by the Christian Doppler Research Association (Austrian Federal Ministry for

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• phenanthrene moiety exhibits a dihedral angle of approximately 22°. Upon comparing the UV–vis spectra of the angular structures 37 and 38, it was observed that after the Ir-catalyzed cycloaddition reaction, the λmax of product 38 considerably blue shifted in comparison to the λmax of 37. Xia et al. also

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• registering the UV–vis spectra of a series of hdz-NO2 10% DMSO/buffer (acetate, phosphate or Tris-HCl) solutions with different pH values, ranging from 3.8 to 8.2 (Figure 7A). By plotting the absorbance at λmax as a function of pH and then fitting the curve with a sigmoidal function (Figure 7A, inset), an

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

• performed using either a Bruker LC-Quadrupole-Time-of Flight tandem mass spectrometer or a Bruker Autoflex MALDI-TOF mass spectrometer. UV–vis spectra were recorded using a Perkin Elmer Lambda 1050 UV–vis–NIR spectrometer. Luminescence emission spectra and lifetimes were analyzed using an Edinburgh

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• -FB, and CN-PDIN-B. b) Normalized solution UV–visible spectra using ethyl acetate as the solvent. c) UV–vis spectra for films on quartz substrates where films were cast from 1 mg/mL solutions using ethyl acetate as the solvent. a) PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-B structures with their

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

• copper(II) porphyrins 3–8. Finally, the structures of all newly synthesized benzo[f]chromeno[2,3-h]quinoxalinoporphyrins 3–16 and benzo[f]quinoxalinoporphyrin 17 were assigned on the basis of IR, 1H and 13C NMR, and HRMS data analysis. Photophysical characteristics The UV–vis spectra of the newly

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• 2450 spectrophotometer (Kyoto, Japan) was used to measure the UV–vis spectra at a concentration of 0.02 mg/mL in MeOH. The chemicals and solvents (analytical and HPLC grade) were purchased from Merck KGaA (Darmstadt, Germany), AppliChem GmbH (Darmstadt, Germany), Carl Roth GmbH & Co. KG (Karlsruhe

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

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

• packing of almost linear molecules (Figure S69, Supporting Information File 1). UV–vis spectra and redox properties As stated above, oligomers 5 are cross-conjugated π-systems. For cross-conjugated structures, the main question is about the preferential conjugation path. For oligomers 5, two different

• . Noncovalent interactions of molecules in crystals and packing effects do not allow one to strictly judge the charge transfer in the oligomers 5. Therefore, we analyzed their UV–vis spectra (Table 3, Figure 8). The functional groups R are located at the far ends of the oligomeric chain and, from the steric

• 6 is identical to the “blue” one in oligomers 5 (Figure 7). Thus, the UV–vis spectra of compounds 1 and 6 were used for comparison (Table 3, Figure 8). The long-wave absorption maximum of the yellow-colored butadiyne 1 is observed at 429 nm (lg ε = 4.33) [15]. Compounds 5a‒с (R = H, OMe, CF3) are

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

• % yield, respectively. Compounds are stable in the refrigerator for more than six months; however, after one year partial decomposition of sample Phen-Py-2 was observed. Spectroscopic characterization of Phen-Py-1 and Phen-Py-2 in aqueous solution UV–vis spectra Studied compounds Phen-Py-1 and Phen-Py-2

• decrease of UV–vis spectra upon heating up to 90 °C and a baseline increase indicated intermolecular stacking and aggregation of compounds, which was more pronounced for Phen-Py-2. Spectroscopic characterization data are given in the Table 1 and Supporting Information File 1, Figure S1. A linker between

• . (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

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• binding calculated from ITC experiments. Supporting Information Supporting Information File 326: Synthetic procedures, characterization, 1H, 13C DEPT, 2D NMR, IR, UV–vis spectra of synthesized compounds; UV–vis spectra of tetracene solutions in DMSO; ITC thermograms. Funding This work has been supported

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• oriented towards the Fe atom. According to the computations, 8b-I is also slightly more advantageous compared to 8c with the same energy difference. The experimental UV–vis spectra of 8b and 8c in CH2Cl2 were similar and contained bands at about 280, 320, and 380 nm. The bands at 280 and 320 nm were more

• ), P1–C1 1.837(3) for 6c. Deposition numbers 2176393 for 5c and 2176394 for 6c contain the supplementary crystallographic data for this paper [41]. Considered conformations of 8b-I and 8b-II. Top: experimental UV–vis spectra of 8с (black) and 8b (red). Bottom: broadened calculated UV–vis spectra of 8c

• (black), 8b-I (red), and 8b-II (blue). Experimental UV–vis spectra of 8с republished with permission of Royal Society of Chemistry from [37] (“Synthesis, structure and electrochemical properties of 3,4,5-triaryl-1,2-diphosphaferocenes” by I. A. Bezkishko et al., Inorg. Chem. Front., vol. 9, Issue 11

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• ], in combination with donor polymer 15, both fused thiophene systems, achieved a PCE of 18%, as published in 2019, the highest value up to then [31]. With a three component system of PBQx-TF, eC9-2Cl, and F-BTA3, a PCE of 19% was achieved [32]. Normalised UV–vis spectra of EtH-T-DI-DTT in 10−5 M CH2Cl2

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

• S20 in Supporting Information File 1). The UV–vis spectra of all compounds in H2O are shown in Figure S17 (Supporting Information File 1). The fluorescence intensities of the ring-fused compounds 3a,b gradually decreased with increasing water fractions, and the ratio of water to ethanol Φ values (ΦH2O

• –vis spectra of all compounds were recorded in ethanol (EtOH), a polar solvent, and in dichloromethane (DCM), a non-polar solvent (see Figures S15–S17 in Supporting Information File 1). The maximum absorption peaks (λmax) shifted slightly to longer wavelengths in dichloromethane. Table 2 summarizes the

• introduction of pyridine rings has not been examined. Our simple one-pot method easily enables the introduction of a pyridine group to maleimide under mild conditions, affording the A–D–A-type molecules that are expected to be novel low-molecular-weight fluorescent materials in moderately good yields. The UV

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

• Jun-Xian Gou,
• Yang Luo,
• Xi-Nan Yang,
• Wei Zhang,
• Ji-Hong Lu,
• Zhu Tao and
• Xin Xiao

Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204

• the reason why the proton signals and absorbance of TBT in the 1H NMR and UV–vis spectra greatly declines. Then SEM and dynamic light scattering (DLS) are used for in-depth research of Q[8]-TBT complex. As shown in Figure 4b, compared with TBT (5.35 nm), the particle size of Q[8]-TBT is greatly

• ), 0.6 (iv), 1.0 (v) to 1.4 equiv (vi), and the 1H NMR of free TMeQ[6] (vii) in D2O. The 1H NMR titration of TBT (1 mM) with an increasing amount of Q[7] from 0 (i), 0.1 (ii), 0.5 (iii), 1.0 (iv), 2.0 (v) to 3.0 equiv (vi) in D2O. The UV–vis spectra (a) of TBT (20 μM) with an increasing amount of Q[7

• ] from 0.0 to 4.0 equiv; the plots (b) of NQ[7]/NTBT vs absorbance of TBT in water at λ = 286 nm. The UV–vis spectra (a) of TBT (20 μM) with an increasing amount of Q[8] from 0.0 to 4.0 equiv and the DLS of TBT (20 μM) and Q[8]-TBT (3:1, 20 μM). The UV–vis spectra (a) of Q[7]-TBT (3:1, 20 μM) affected by

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• ) were determined and the values are presented in Table 2. All UV–vis spectra of the DPBF photooxidation are shown in Supporting Information File 1 (Figures S8–S17). In general, all compounds at a concentration of 0.5 μM showed weak photooxidization tendency against DPBF quencher at 50 μM (e.g., 3bb

• /cm2 and total light dosage 90 J/cm2 at 60 min, according to the current literature. All experiments were performed in duplicate and independently. In order to measure 1O2 generation ability, UV–vis spectra of the solutions (samples and standard) were recorded for different exposure times by using a

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• the photoinduced CuAAC reactions. UV–vis spectra of CuICl, CuIICl2 and BPNs. a) 1H NMR spectra of the model reaction between benzyl azide (Az-1) and phenylacetylene (Alk-3) before (black) and after (red) irradiation. b) Conversion-time plot as measured by 1H NMR spectroscopy through integration of the

• 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

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

• ) relative to tetramethylsilane (SiMe4) as internal standard. High-resolution MS (HRMS–ESI) was performed on an Agilent 1969 A TOF. The photophysical studies were carried out in freshly prepared dichloromethane solutions with concentrations of 1 × 10−5 M. The UV–vis spectra were recorded on a Shimadzu 2401

Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones

• Girish Suresh Yedase,
• Sumit Kumar,
• Jessica Stahl,
• Burkhard König and
• Veera Reddy Yatham

Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121

• mixing the (n-Bu4N)2CeIVCl6 complex with BnOH under basic conditions. The UV–vis spectra of the CeIV(OBn)Cln complex displayed a band resembling the LMCT band of known cerium–alkoxide complexes, showing considerable overlap with the blue LED region, thus suggesting that the CeIV(OBn)Cln species could be

• photoexcited (Figure 1A). We then analyzed UV–vis spectra of the CeIV(OBn)Cln complex recorded after irradiation with blue light at different time intervals. As shown in Figure 1A, the absorption spectrum of the CeIV(OBn)Cln complex gradually shifted from λmax = 375 nm to λmax = 325 nm upon irradiation, which

• and secondary benzylic alcohols were converted into the corresponding aldehydes and ketones in good to moderate yields using commercially available and inexpensive CeCl3·7H2O as a photocatalyst and air as an oxidant. Mechanistic studies. (A): UV–vis spectra of the CeIV(OBn)Cln complex in CH3CN under

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

• characterization of 1H NMR spectra: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet. Chemical shifts were given in ppm (δ) relative to tetramethylsilane (SiMe4). Photophysical studies were carried out in freshly prepared dichloromethane solutions with concentrations of 1 × 10−5 M. UV–vis spectra