Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• coefficient, c is the concentration of a light-absorbing solute, and d is the optical path length. Figure 8 shows the measured absorbance as function of the photocatalyst loadings in the methanol/water solution using different optical path lengths. The absorbance depends linearly on the photocatalyst

• generation rate as function of irradiation time. The hydrogen generation rate first increases to a maximum value and decreases subsequently. After around 10 hours of irradiation, a steady level of hydrogen evolution is reached. Even though some fluctuations in the range of ±8% can be observed, the hydrogen

• different irradiation time, (b) photon flux at different irradiation time. Photon flux in the loop reactor with respect to the LED electrical current. Absorbance as function of photocatalyst loading for different optical path lengths. Long-term operation of the loop photoreactor. Visualization of the

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• ][30]. If the DWCNTs align parallel to the long axis of the spindle droplet, it is referred to as a homogenous tactoid. Conversely, if the DWCNTs align from one pole to another, it is called a bipolar tactoid. Figure 3 illustrates the aspect ratio of the tactoids (R/r) as a function of the tactoid

• concentration against the CNT aspect ratio L/D of three CNT-SC aqueous dispersions [22][23]. Dashed lines indicate the results of curve fitting by inverse function in each phase transition, from isotropic phase to biphasic state and from biphasic state to nematic phase. Observed tactoid aspect ratio R/r as a

• function of tactoid volume Rr2. Filled circle and open circle indicate bipolar tactoid and homogenous tactoid respectively. Dashed line denotes the estimated transition volume from homogenous to bipolar tactoids (=15310 μm3). (a, b) POM images of the DWCNT film at (a) 0° and (b) 45° under crossed

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• grasp functionality would make it a preselected tool for the review process of chemistry publications. Future developments of NMRium include the processing of 2D NMR experiments, as well as a CASE- and prediction-supported assignment tool with an integrated validation function for assigned data [44

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• , Supporting Information File 1). Next, we analyzed the function of CmaA6, which was predicted to catalyze the diazotization of 3-aminocoumaric acid (3-ACA, 3) in p-coumaric acid biosynthesis. As expected, 3-diazocoumaric acid (3-DCA, 4) was synthesized by CmaA6 in the presence of ATP and sodium nitrite

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• is usually associated with promiscuous annealing and secondary structures. Problematically, many secondary structures such as hairpin, cruciform, and G-quadruplex are actually needed for genes and genomes to function, and thus these genes and genomes may not be accessible. (4) Genes having long

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• -normalized initial reaction rate (d([RX]/dt)0/[D2]0) as a function of the initial benzyl bromide concentration ([RX]0) obtained from several experiments of the type shown in part (a) for different [D2] and [RX] for both D2 = (Cyc-DMBI)2 and (N-DMBI)2. For these slow reactions, the “initial” rates were

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• to C60 fullerenes [12]. These amines function as bases, their position next to the aromatic surface is essential to turn on anion–π interactions as soon as substrate 4 is deprotonated. Fullerene derivatization with the Bingel reaction installs a cyclopropane that continues with one or two acid

• monomeric fullerenes (22, A/D = 4.6) but weaker than on fullerene dimers (37, A/D = 12.5). The true activity is presumably much higher because MWCNTs, and SWCNTs, are heterogenous catalysts that operate as suspensions with only a minor fraction of the total π surface accessible for function. Fullerene

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

• of TOF measurements. The similar situation was in the case of the other compounds which showed current transients without detectable transit times (Figure S7 in Supporting Information File 1). The electron mobility (µe) as the function of the electric field was substantial for 7 with the field

• under a nitrogen atmosphere. TGA allows us to observe the weight changes of the samples as a function of temperature, providing valuable insights into processes such as decomposition, volatilization, and oxidation. In the case of DSC measurements, the samples were heated at a rate of 10 °C/min in a

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• crystal has two independent units of 3a and three CS2 molecules as guest solvents. The difference between the two independent units is the direction of the tolyl group in the crystal (Supporting Information File 1, Figure S7). (a) Charge density of La@C2v-C82 anion as a function of its POAV values and (b

• ) an enlarged part view of blue region in (a). (c) Spin density of La@C2v-C82 as a function of its POAV values [34][35]. (d) Molecular structure of La@C2v-C82 and numbering carbon atoms. Reaction of the La@C2v-C82 anion with benzyl bromide derivatives. Charge densities and POAV values of carbon atoms

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• vibrational resonances as a function of their frequency in the mid-IR range. After measuring its mass and its IR fingerprint, an unknown analyte (Figure 1a) is readily identified as "GlcNAc" (for N-acetylglucosamine) by comparison with the reference IR spectra of several candidates of identical mass (Figure

• ) activation functions for each layer. Two dropout layers are interleaved after the first and second hidden layers with a dropout setting of 25% to avoid over-fitting issues. The training objective is a classification task between the 4 monomer categories with a cross-entropy loss function. To account for the

• , energy shift, and downsampling. The mean accuracy of the model as a function of these four parameters is shown in Figure 4. Note that all parameters have a uniform distribution over the 8000 samples and can be studied independently. The amplitude modulation and downsampling do not play a major role, with

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• avicennae [18]. Inhibition of hepatitis C virus replication by 2-nonyl-4-quinolone, isolated from Ruta angustifolia leaves, has also been reported [19]. Another significant group of natural 4-quinolones are those of microbial origin. The function of these compounds in the microbial world is a matter of

• great research interest, with many reviews published in the recent years [20][21][22]. Some of the compounds are known to act as antibiotics [23][24][25][26], while others function as quorum-sensing signal molecules which regulate the production and release of virulence factors in bacteria, thus helping

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• -shifted in the film. These results indicate molecular π-stacking aggregation and excimer formation on the films [2]. The PL in film was obtained as a function of temperature (Figure 4). The observed reduction of the PL intensity on heating is expected for organic semiconductors due to self-quenching

• the mobility μ(E) at an electric field of 6.0 × 105 V/cm. Figure 7 shows the charge carrier mobility as a function of the applied electric field, calculated from . The electron mobility of 1 is around one order of magnitude lower than that of holes, depending on the electric field. It suggests that

• Optics USB4000 spectrophotometer. The PL spectra were collected with a Hitachi fluorescence spectrophotometer (Model F-7000) and the samples were excited at the wavelength of maximal absorption. For the PL as a function of the temperature, casting films were placed on a hot stage (Mettler Toledo FP-82

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

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• self-assembled monolayer in devices. The molecular dipole and work function of gold was adjusted by using fluorine and CN as well as dimethylamino substituents on the quinoxaline. Notably, the researchers tuned the work function of gold over a range of 1.0 eV [59]. The study by You et al. quoted in the

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

• , the molecule contains both the intrinsic LE and CT excited states or demonstrates HLCT characteristics. Besides, the Stokes shifts between absorption and emission spectra were plotted as a function of solvent polarity function (Δf) corresponding to the Lipper–Mataga model which defines the

• electron-only MIS device and 15 μs and −5 V for the hole-only MIS device, respectively, and their MIS-CELIV signal transient plots as a function of time are shown in Figure 6c and 6d. As the applied voltage increased, it was found that the transient peak shifted to slightly shorter times indicating an

• increasing carrier mobility. The hole and electron mobilities (μ) were calculated and plotted as a function of electric field (E1/2). As illustrated in Figure 6b, the mobility (μ) of both holes and electrons is electric field dependent and gradually increases on increasing the electric field, which is

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

• over 19% used a BHJ of PM6:BTP-eC9 with PFN-Br as the CIL [6]. CILs serve to increase device performance in various ways. First, polar functional groups (and induced dipole moments) serve to tune the work function of the cathode for a reduced energetic offset, thus reducing the Schottky barrier that is

• and acceptor molecules (N···F and N···H bonding when using the acceptor Y6), as well as an induced dipole moment in the molecule for increased work function tuning of the cathode. The use of benzyl and pentafluorobenzyl substituents was to evaluate the impact of H vs F on the electrochemical

• [19]. The energy level diagram of each respective layer in the device are represented in Figure 5c, where PEDOT:PSS, PM6, and Y6 work function and energy levels were taken from literature [17][30]. We evaluated the current density–voltage (J–V) in the dark and under illumination (AM1.5 G at 100 mW/cm2

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• procedure: Optimization of the R[4]A and sec-amine geometries was performed with the GFN2-xTB method using the ALPB solvent model with the “veryTight” accuracy using the xTB software package [29]. Complex assembly search (aISS) was performed using the “dock” function with “tight” optimization of the

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• studied. Several 2-methylisoborneol synthases have a proline-rich N-terminal domain of unknown function. The results presented here demonstrate that this domain leads to a reduced enzyme activity, in addition to its ability to increase long-term solubility of the protein. Furthermore, the substrate scope

• versions of 2MIBSs exhibit a proline-rich N-terminal domain of unknown function that appears disordered in the crystal structure [28]. As a first aspect of this study, we have investigated the possible function of this N-terminal domain. 2MIBS is known to form several methylated monoterpenes as side

• changed alkylation pattern. Results and Discussion Function of the proline-rich N-terminal domain of 2MIBS S. coelicolor 2MIBS was selected to investigate the function of the proline-rich N-terminal domain (hereafter termed A domain, the C-terminal domain is named as domain B). Based on a sequence

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• results is in agreement with the formation of a zinc enolate that undergoes proto- (or deuterio)demetalation with the N–H (or N–D) as proton (or deuterium) source. To further analyze the influence of the presence of an N–H function, we performed other reactions with N-benzyl enoate 10 which proved highly

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• related enzymes from other actinomycetes with a pairwise identity of 69% may also function as (+)-δ-cadinol synthases (Figure S11, Supporting Information File 1). The enzyme from S. jumonjiensis (Table 1, entry 2) showed the fully established conserved motifs including the aspartate-rich region (83DDVRSE

• Chitinophaga pinensis [29][30], but no α-cadinene synthase has been reported to date. The enzyme newly described here was designated as Streptomyces jumonjiensis (+)-α-Cadinene Synthase (SjaCS). A few more enzymes with a pairwise identity of 83% are observed in other actinomycetes that likely also function as

• identity of only 48% sufficiently distant so that another function could be expected (Figure S34, Supporting Information File 1). However, the incubation with FPP resulted in the efficient formation of epi-isozizaene (13) as a single product (Figure 5), confirming the same function as for known EIZS and

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• compounds. Keywords: amphiphiles; edelfosine; GAEL; glycerol lipids; glycolipids; ohmline; plasmalogen; Introduction Ether lipids (ELs) are natural compounds that feature a glycerol unit linked with an ether function to an alkyl (alkyl acyl ether lipid) or alkenyl (plasmalogen) lipid chain. For the

• alkenyl compounds, the vinyl ether function is characterized by a (Z)-configuration as shown in Figure 1. In addition, an acyl group is present on the secondary alcohol of the glycerol. This acyl group is constituted by a saturated or unsaturated lipid chain or, in the case of platelet-activating factor

• noted that ELs are essential players of cell signaling [25]. Together, all these studies point out that ELs are essential for a multitude of biological functions [26] despite their mode of action is not yet fully understood. From a molecular point of view, the ether function present in alkenyl ELs

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

• Valeriy O. Filimonov,
• Alexandra I. Topchiy,
• Vladimir G. Ilkin,
• Tetyana V. Beryozkina and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2023, 19, 1191–1197, doi:10.3762/bjoc.19.87

• -(substituted)phenylsulfonyl-4-thiocarbamoylpyrazoles in moderate to high yields. It was concluded that in 2-cyanothioacetamides, cyano and enamino groups are more active in the reaction with hydrazines than the thiocarbamoyl function. Experimental X-ray structure determination of 5b, 6a, 7a 5b: Crystal data

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

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• (40 μM) and 1 (2 mM) in citrate phospate buffer pH 3 (right) from 350–400 nm with 0 (blue), 2 (red), 4 (green), 6 (orange) and 8 (grey) bar of CO2. Binding of CO2 to 1 as a function of pressure. The results of crystallization of α-cyclodextrin from water in an atmosphere of CO2 carried out in a

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• ). The function of squaric acid as a catalyst was not clear, but the authors suggested that the Brønsted acidity of squaric acid affects the reactivity and selectivity of this process. The tentative mechanism of this protocol was proposed (Scheme 13b), in which a reversible acid–base reaction of aniline