The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• produced gases (Figures S11 and S12, Supporting Information File 1). The CAHOF F-1 was also analyzed by nitrogen porosimetry (see Supporting Information File 1). It was found to contain mesopores and macropores with an adsorption average pore width of 5.2 nm, a BET surface area of 2.606 m2⋅g−1, a mesopore

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• /mechanical stability, and good adsorption capacity. They also contain an ordered porous network that is appropriate for the free diffusion of reactants and reaction products [24]. In this regard, various functionalized SiO2 nanoparticles were employed in diverse organic reactions, including Suzuki–Miyaura

Carbazole-functionalized hyper-cross-linked polymers for CO₂ uptake based on Friedel–Crafts polymerization on 9-phenylcarbazole

• Dandan Fang,
• Xiaodong Li,
• Meishuai Zou,
• Xiaoyan Guo and
• Aijuan Zhang

Beilstein J. Org. Chem. 2019, 15, 2856–2863, doi:10.3762/bjoc.15.279

• a high surface area and a high total pore volume. The BET specific surface areas of P3 was up to 769 m2 g−1 with narrow pore size distribution and the CO2 adsorption capacity of P11 was up to 52.4 cm3 g−1 (273 K/1.00 bar). Keywords: 9-phenylcarbazole; CO2 uptake; Friedel–Crafts polymerization

• amorphous polymers [12] (Figure 5). Porous properties The permanent porous nature was subsequently studied by subjecting the polymers to nitrogen adsorption–desorption experiments at 77 K. The porosity data of P1–P11 are listed in Table 2. The main influence of the porous properties is the reaction degree

• , P2–P5 exhibited a rapid nitrogen adsorption ability at low pressures (P/P0 < 0.05, Figure 6a), which indicated that the micropores exist in the networks [35]. The sorption isotherm of P2–P4 exhibited a combination of type I and IV nitrogen sorption isotherms according to the IUPAC classification [36

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• electrodes Electrodes with chiral surfaces have long been prepared through the adsorption of chiral active auxiliaries onto the surface of the metallic electrode. In such cases, the chiral electrode becomes an inherent part of the electrochemical cell and serves as a heterogeneous catalyst. A recent article

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• with different numbers of sides [18], that are scalable to some extent [19]. The long alkoxy side chains mediate sufficient compound solubility and compound adsorption on highly oriented pyrolytic graphite (HOPG) that acts as a template [20][21], and determine the intermolecular interaction [22][23][24

• , some rows of more densely packed molecules (polymorph B) are observed, where two (arrow 1 in Figure 3a) or all four (arrow 2 in Figure 3a) decyloxy side chains are oriented towards the intraannular region. This is consistent with the spatial requirements of 2, which compete with the adsorption of 1a

•  1). Conclusion Arylene–alkynylenes that carry alkoxy side chains form, after adsorption to graphite, a nanopattern with intra- and intermolecular nanopores. Clusters of otherwise unhinderedly mobile 1,2,4-trichlorobenzene solvent molecules are found in these nanopores. Subtle changes of the pore

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

• Roland Löw,
• Talina Rusch,
• Tobias Moje,
• Fynn Röhricht,
• Olaf M. Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

• ]. Three molecular units are combined in a modular way to achieve a controlled adsorption on the surface: the platform, a spacer and the functional molecule. Triazatriangulenium (TATA) and trioxatriangulenium (TOTA) units are used as molecular platforms. They adsorb on the surface and form ordered

• as realized in compound 1. Consequently, future surface chemistry investigations will be performed with compound 1 including the TATA platform and an ethynyl spacer. STM Measurements The adsorption behaviour of the NBD 1a on Au(111) surfaces was studied by scanning tunnelling microscopy (STM) at room

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• electrolyte one can tune the electronic properties, i.e., the CB energy level position of TiO2 [31][37][38][39]. The effect is well-known, a negative dipole-related shift of the TiO2 Fermi level occurs by tBP adsorption on the surface. As the LUMO levels of the dyes are estimated close to the CB Fermi level

Synthesis and conformational preferences of short analogues of antifreeze glycopeptides (AFGP)

• Małgorzata Urbańczyk,
• Michał Jewgiński,
• Joanna Krzciuk-Gula,
• Jerzy Góra,
• Rafał Latajka and
• Norbert Sewald

Beilstein J. Org. Chem. 2019, 15, 1581–1591, doi:10.3762/bjoc.15.162

• microscopic mechanism of ice–glycoprotein interaction is still unknown. Therefore, it is an interesting area for further research [3][10][11]. Some studies have highlighted the role of irreversible adsorption of AFGPs onto growing ice surface and incorporation of hydroxy groups of the disaccharide subunit

• into the ice lattice [12], others investigated the adsorption process on different surfaces via atomic force microscopy [10][13][14]. The antifreeze activity has been correlated with long-range perturbation of hydration dynamics [15]. Latest molecular dynamics simulations suggest that AFGP reversibly

Diazocine-functionalized TATA platforms

• Roland Löw,
• Talina Rusch,
• Fynn Röhricht,
• Olaf Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1485–1490, doi:10.3762/bjoc.15.150

• . The half-lives (298 K) are similar for both systems (2.12 h for 1 and 2.32 h for 2). The lack of conjugation between the azo function and the ethynyl spacer of 2 yields in a slightly higher half-life, which is in agreement with earlier results [11]. STM Measurements The adsorption behavior of the

Reaction of oxiranes with cyclodextrins under high-energy ball-milling conditions

• László Jicsinszky,
• Federica Calsolaro,
• Katia Martina,
• Fabio Bucciol,
• Maela Manzoli and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2019, 15, 1448–1459, doi:10.3762/bjoc.15.145

• seen in Figure 2 and Figure 3. Although scaled-up β-CDP has somehow larger particles, complexation studies with methyl orange (MO) only showed small differences. Although complex formation with MO showed similar behaviour to previous reports [13], adsorption capacity seems to be considerably lower than

• that of bead polymers in all cases. The adsorption of MO shows apparent first order kinetics, and the largest adsorption rates were accordingly found at the beginning of adsorption. The adsorption isotherm of insoluble β-CDP was recorded after 1 day and 2 weeks of equilibration. The adsorption isotherm

• GPTS-γ-CD. The adsorption isotherm can also be divided in two parts; the simple adsorptive removal of MO can be seen at the beginning, while the MO peak showed a noticeable blue-shift as the amount of solubilised/dissolved γ-CD-derivative increased. Conclusion The use of the HEBM method to force the

Mechanochemical amorphization of chitin: impact of apparatus material on performance and contamination

• Thomas Di Nardo and
• Audrey Moores

Beilstein J. Org. Chem. 2019, 15, 1217–1225, doi:10.3762/bjoc.15.119

• amounts of material from the jars and balls in the reagents and products as a contamination. Milling media can have a catalytic effect due to leaching or surface adsorption [7][35][36][37]. Contamination has been noted in alloying [26][38] as well as amorphization of hard materials [39], and could cause

Mechanochemical synthesis of hyper-crosslinked polymers: influences on their pore structure and adsorption behaviour for organic vapors

• Sven Grätz,
• Sebastian Zink,
• Hanna Kraffczyk,
• Marcus Rose and
• Lars Borchardt

Beilstein J. Org. Chem. 2019, 15, 1154–1161, doi:10.3762/bjoc.15.112

• intrinsic property. Thus, the pore volume and specific surface area that is permanently accessible can be increased by a severe swelling behaviour especially during the adsorption and combined with absorption of organic vapors or liquids. The swelling is fully reversible, thus, rendering these materials

• interesting adsorbents with a dynamic adsorption behaviour. However, the low solubility of POPs is a main challenge in their synthesis protocols. Solution-based procedures, for example, suffer from almost instant precipitation and thus only produce materials with a low degree of polymerization [10]. In the

• obtained for diethyl ether (Table 1, entry 7) this sample has been denoted LAG-HCP and was investigated further. Vapor physisorption Since HCP is highly hydrophobic (proven before by water vapor physisorption [11]), the adsorption of non-polar adsorptives in the gas and liquid phase is strongly favored

Fabrication, characterization and adsorption properties of cucurbit[7]uril-functionalized polycaprolactone electrospun nanofibrous membranes

• Changzhong Chen,
• Fengbo Liu,
• Xiongzhi Zhang,
• Zhiyong Zhao and
• Simin Liu

Beilstein J. Org. Chem. 2019, 15, 992–999, doi:10.3762/bjoc.15.97

• present in the PCL fiber matrix in an uncomplexed state. The static adsorption behavior of the PCL/CB[7] nanofibers towards methylene blue (MB) was also preliminary investigated. The results indicate that the adsorption of MB onto the nanofibrous membranes fits the second-order kinetic model and Langmuir

• isotherm model. Keywords: adsorption; cucurbit[7]uril; electrospinning; macrocycles; methylene blue; nanofiber; Introduction Electrospinning is recognized as the most simple and versatile method to fabricate multifunctional nanofibers from the solution or melt of polymers, polymer/nanoparticle mixtures

• ]-containing functional materials, the feasibility of CB[7] (the chemical structure is shown in Supporting Information File 1, Figure S1)-based nanofibers through electrospinning was studied for the first time. In addition, the adsorption properties of the fabricated nanofibers were also preliminarily

Synthesis of polydicyclopentadiene using the Cp₂TiCl₂/Et₂AlCl catalytic system and thin-layer oxidation of the polymer in air

• Zhargolma B. Bazarova,
• Ludmila S. Soroka,
• Alex A. Lyapkov,
• Мekhman S. Yusubov and
• Francis Verpoort

Beilstein J. Org. Chem. 2019, 15, 733–745, doi:10.3762/bjoc.15.69

• and can be determined by the increase of carbonyl and hydroxyl adsorption bands in infrared spectra. Along with oxidation, cross-linking processes occur in polymers, which lead to a change in physical parameters of the layers, and more precisely to a decrease in the permeability of atmospheric oxygen

• adsorption of oxygen and its transport through the polymer layer becomes the slowest process, which leads to a change in shape of the kinetic curve of the accumulation of peroxide radicals (Figure 13). The curve in Figure 13 averages the experimental points of the oxidation process and is a result of two

• to air oxidation for 700 hours. DSC exotherm for PDCPD subjected to unexposed film: 1) in air atmosphere; 2) in argon. Dependence of intensities of adsorption bands at 1410 and 700 cm−1 and dwell time of the layer in air at ambient temperature. Semi-logarithmic kinetic curve of PDCPD oxidation in air

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

MoO₃ on zeolites MCM-22, MCM-56 and 2D-MFI as catalysts for 1-octene metathesis

• Hynek Balcar,
• Martin Kubů,
• Naděžda Žilková and
• Mariya Shamzhy

Beilstein J. Org. Chem. 2018, 14, 2931–2939, doi:10.3762/bjoc.14.272

• . Moreover, for related system based on tungsten oxide in zeolite, it was suggested using high resolution STEM that Brønsted acid sites in proximity to metathesis active sites facilitate olefin adsorption and metallocycle formation [29]. Such mechanism may be effective also for Mo catalysts. The decrease in

• temperature for 3 h. The supports were characterized by XRD (Bruker AXS D8 Advance diffractometer with a graphite monochromator and a Vantec-1 position sensitive detector using Cu Kα radiation in Bragg−Brentano geometry) and by N2 adsorption (77 K, Micromeritics GEMINI II 2370 volumetric Surface Area Analyzer

• adsorption was carried out at 150 °C and a partial pressure of 3.5 torr for 20 min followed by desorption for 20 min at 150, 250, 350 or 450 °C. Before adsorption, pyridine was degassed by freeze–pump–thaw cycles. All spectra were recorded with a resolution of 4 cm–1 by collecting 128 scans for a single

Synthesis of unnatural α-amino esters using ethyl nitroacetate and condensation or cycloaddition reactions

• Glwadys Gagnot,
• Vincent Hervin,
• Eloi P. Coutant,
• Sarah Desmons,
• Racha Baatallah,
• Victor Monnot and
• Yves L. Janin

Beilstein J. Org. Chem. 2018, 14, 2846–2852, doi:10.3762/bjoc.14.263

• heat, adsorption over silica, acids (BF3·OEt2, AcOH) or bases (NEt3, LDA, EtONa) all failed to change the ratio of compounds 28 and 29, which were isolated in 5 and 28% yield, respectively. Despite the potential synthetic interest [29][30] of isoxazole 28, we did not pursue this further, but focused on

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• was produced and defined as s-MWCNTs 137 (Scheme 25). In the next step, the type of acid sites on this solid product was identified via pyridine-FTIR spectroscopy. The FTIR spectrum of s-MWCNTs 137 before pyridine adsorption showed no sharp signal, but the FTIR spectrum of s-MWCNTs after pyridine

• adsorption showed some peaks at 1646, 1626, 1549 and 1476 cm−1. The peaks at 1646, 1626, and 1549 cm−1 could be due to the vibration of pyridinium (PyH+) species, corresponding to the existence of Brønsted acid sites on the s-MWCNTs 137. The peak at 1476 cm−1 was also labeled to the coordination of electron

• before use in the reaction. This causes that the tendency of adsorption of PFAD on active sites was decreased and consequently the catalyst will not be deactivated. A covalently grafting modified nanoscaled diamond powder with 1,3-propanesultone (Scheme 26) 138 exhibited excellent catalytic activity for

Dispersion-mediated steering of organic adsorbates on a precovered silicon surface

• Lisa Pecher,
• Sebastian Schmidt and
• Ralf Tonner

Beilstein J. Org. Chem. 2018, 14, 2715–2721, doi:10.3762/bjoc.14.249

• the neighbouring adsorption site. This helps in understanding the nonstatistical pattern formation for this surface–adsorbate system and hints toward an inclusion of dispersion attraction as another determining factor for surface adsorption. Keywords: bonding analysis; cyclooctyne; density functional

• missing a second functional group necessary for the LbL approach, previous studies have shown that synthetic routes exist for derivatization and that the reactivity of the strained triple bond of 1 with the surface is not affected by the second functional group [4][5][9]. Studying the adsorption behaviour

• of the parent system 1 thus gives crucial insight that is expected to be transferable to the bifunctional derivatives. The adsorption of a molecule on a surface can proceed either via a direct pathway or via an intermediate species that is crucial for selectivity and the description of adsorption

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• reaction of H2bpdc, Ru(bpy)2Cl2, and a zinc source under solvothermal conditions (bpy = 2,2′-bipyridine, Scheme 5) [41]. The molecular photosensitizer [Ru(bpy)3]2+ was incorporated into the MOF through adsorption to form Ru@MOF, accompanied by a color change. Furthermore, 1 was effectively immobilized on

Selective formation of a zwitterion adduct and bicarbonate salt in the efficient CO₂ fixation by N-benzyl cyclic guanidine under dry and wet conditions

• Yoshiaki Yoshida,
• Naoto Aoyagi and
• Takeshi Endo

Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194

• derivative and CO2 was isolated and characterized for the first time. Keywords: bicarbonate salt; carbon dioxide adsorption; cyclic guanidine; repeatable capture and release; zwitterion adduct; Introduction Recently, various reactions with CO2 as a cheap and green carbon reagent have been developed not

• structure of the guanidine moiety [39]. Furthermore, we also have demonstrated that the adsorption performance of CO2 was fairly different under dry and wet conditions [35]. Previously, Jessop et al. described that the bicarbonate salt of DBU and CO2 was obtained in the presence of water and never confirmed

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• the epoxides of the graphene-family material. In a coupling with the inclusion of graphene-family material and amine hydrohalide some reactions or transformations may occur, but they are based on electrostatic adsorption or hydrogen bonding [23], rather than on covalent modification. If formation of

• vibrations) in the product’s IR spectrum. Therefore, it is not clear why a similar, prominent adsorption band corresponding to the amide moiety was not observed in the spectrum, and this issue was not discussed. It is noteworthy that both a lower intensity of the absorption band coming from the C=O of GO

• ], the approach to the synthesis of the material has not been given in some cases; in other words, the researchers have not always discussed whether the process is based on the non-covalent adsorption of the reactant or whether it follows the nucleophilic addition to GO’s epoxides. On the basis of the

Synthesis of new p-tert-butylcalix[4]arene-based polyammonium triazolyl amphiphiles and their binding with nucleoside phosphates

• Vladimir A. Burilov,
• Guzaliya A. Fatikhova,
• Mariya N. Dokuchaeva,
• Ramil I. Nugmanov,
• Diana A. Mironova,
• Pavel V. Dorovatovskii,
• Victor N. Khrustalev,
• Svetlana E. Solovieva and
• Igor S. Antipin

Beilstein J. Org. Chem. 2018, 14, 1980–1993, doi:10.3762/bjoc.14.173

• packaging density of aggregates and their general lipophilicity. To reveal this, absorbance spectra of the 10b–EY system in the presence of ADP and ATP were recorded (Figure 5a and b). The addition of small amounts of nucleotides leads to a bathochromic shift of the EY adsorption due to a deeper penetration

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

• Mrityunjay K. Sharma,
• Roopashri B. Acharya,
• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

• continuous mode (CSTRs). Preheating and precooling are essential for getting reproducible and reliable experimental data. The third and final module includes separators viz. membrane separators/filters, scavengers or adsorption column (packed column), extractors/gravity separators, dryers, extruders, etc

• (reaction/drying/crystallization/adsorption/desorption), solubility data (extraction/crystallization), etc. This approach is useful for testing proof of the concept for a continuous process of various drugs which are in clinical trials. However, this approach may not be feasible for pilot or production

• cooled to 0 °C in the intermediate storage tank T5. The reaction mixture can pass through separator S1 (adsorption column) which is packed with MS 4 Å to remove the byproduct water. A solution of malonate and triethylamine in toluene are precooled to 0 °C in feed storage tanks and pumped to mixer M6

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• ]. Adsorption of RuP onto Ag/g-C3N4 was conducted by dispersing 40 mg of Ag/g-C3N4 in an acetonitrile (MeCN) solution (20 mL) of RuP. The suspension was stirred overnight at room temperature in the dark to allow for the adsorption/desorption equilibrium, followed by filtration and washing with acetonitrile. The

• filtrates were collected and concentrated to a volume of 30 mL. The amount of the ruthenium complex absorbed was calculated based on the UV–vis spectrum of the filtrate, using Equation 1: where Abefore and Aafter are the absorbance of the solution before and after the adsorption procedure, respectively, and