Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• . Crystals suitable for X-ray structure were obtained in a fritted U-shape tube by the slow diffusion of methanol solutions of in situ-prepared “Fe(H2B(pz)2)2“ and diarylethene 6. Unexpectedly, we have found that the structure of the product depends on the reaction time. Reproducible crystals isolated after

Reversible switching of arylazopyrazole within a metal–organic cage

• Anton I. Hanopolskyi,
• Soumen De,
• Michał J. Białek,
• Yael Diskin-Posner,
• Liat Avram,
• Moran Feller and
• Rafal Klajn

Beilstein J. Org. Chem. 2019, 15, 2398–2407, doi:10.3762/bjoc.15.232

• )22 prior to UV irradiation and, as expected, did not observe any shifts of 1’s signals. To further confirm the photoswitching-induced guest expulsion, we performed detailed diffusion-ordered spectroscopy (DOSY) measurements. A representative DOSY spectrum of (E-1)22 is shown in Figure 7, left. The

• spectrum indicates the presence of a single species (the diffusion coefficient for 1, D1 = 1.91 (±0.01) · 10−10 m2·s−1 (based on averaging Ha and Hd); the diffusion coefficient for 2, D2 = 1.85 (±0.01) · 10−10 m2·s−1 (based on H4); each diffusion measurement was repeated three times). In contrast, DOSY

• spectra recorded after UV irradiation exhibited two distinct sets of diffusion coefficients, associated with resonances of 1 and 2 (red and green shades in Figure 7, center). The average diffusion coefficients were determined as D1 = 3.44 (±0.04) · 10−10 m2·s−1 and D2 = 1.86 (±0.01) · 10−10 m2·s−1. The

Synthesis of a dihalogenated pyridinyl silicon rhodamine for mitochondrial imaging by a halogen dance rearrangement

• Jessica Matthias,
• Thines Kanagasundaram,
• Klaus Kopka and
• Carsten S. Kramer

Beilstein J. Org. Chem. 2019, 15, 2333–2343, doi:10.3762/bjoc.15.226

• . Lipophilic cations such as the phosphonium cation or rhodamines are known to accumulate selectively within the mitochondria, driven by the mitochondrial plasma membrane potential [39][40]. Thereby, the high lipophilicity facilitates the diffusion through the lipid bilayers of the cell and mitochondrial

Isolation of fungi using the diffusion chamber device FIND technology

• Benjamin Libor,
• Henrik Harms,
• Stefan Kehraus,
• Ekaterina Egereva,
• Max Crüsemann and
• Gabriele M. König

Beilstein J. Org. Chem. 2019, 15, 2191–2203, doi:10.3762/bjoc.15.216

• contamination by other microbes. These membranes, at the same time, permit diffusion of nutrients and growth factors from the environment through the feeding pores of the upper and lower plates. This way slow growing fungi or to date uncultured fungi can be isolated. To test the FIND technology, we used samples

• other 10 isolates grown on BMS medium were tested in disk diffusion assays using 50 µg of extract per disk. None of the extracts was active against the Gram-negative bacterium E. coli. Extracts of A. armoraciae, Auxarthron umbrinum, C. globosum, Chrysosporium sp. 831, C. allicinum, C. rosea, H. cf

• (Leica, Wetzlar, Germany) and micromorphology was examined with an Olympus BX51 polarizing microscope (Olympus, Shinjuku, Japan) by analysis of conidia and mycelium to support the bioinformatic suggestions. Fermentation, extraction and isolation For cultivation of the marine isolates from the diffusion

Multiple threading of a triple-calix[6]arene host

• Veronica Iuliano,
• Roberta Ciao,
• Emanuele Vignola,
• Carmen Talotta,
• Patrizia Iannece,
• Margherita De Rosa,
• Annunziata Soriente,
• Carmine Gaeta and
• Placido Neri

Beilstein J. Org. Chem. 2019, 15, 2092–2104, doi:10.3762/bjoc.15.207

• diffusion coefficient of 7.06 × 10−11 m2/s attributable to the 7+6 pseudo[2]rotaxane as TFPB− salt and significantly lower than that measured for the free triple-calix[6]arene host 6 of 3.02 × 10–10 m2/s. Through an 1H NMR quantitative analysis of a 1:1 mixture of 7+·TFPB– and 6 in CDCl3, using 1,1,2,2

Synthesis and anion binding properties of phthalimide-containing corona[6]arenes

• Meng-Di Gu,
• Yao Lu and
• Mei-Xiang Wang

Beilstein J. Org. Chem. 2019, 15, 1976–1983, doi:10.3762/bjoc.15.193

• -corona[6]arenes in the solid state, high quality single crystals of 3a were grown at room temperature from diffusion of diethyl ether vapor into the solution of 3a in acetonitrile. X-ray diffraction analysis revealed that the macrocycle 3a adopted an interesting conformation. As depicted in Figure 1, it

• ability of 3a to bind various anion species in gas phase. To our delight, host molecule 3a co-crystalized with n-Bu4NX (X = Cl, Br) from diffusion of diethyl ether vapor into ethyl acetate solution at ambient temperature to give single crystals of the host–guest complexes (n-Bu4NX)3-3a (X = Cl, Br). X-ray

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• (ArgOMe)2 that may come from the differences in stability of the complexes. This qualitative observation is supported by DOSY measurements (Figure 4) [24]. DOSY measurements indicate that for [1(LysOMe)2]MeOH the two components of the complex exhibit noticeably different diffusion coefficients (D) with a

• lower value for 1 (3.6 × 10−10 m2 s−1, methanol-d4, 298 K) and slightly higher value for LysOMe (4.0 × 10−10 m2 s−1, methanol-d4, 298 K). This suggests that under such conditions [1(LysOMe)2]MeOH partially dissociates and the LysOMe component exhibits a diffusion coefficient that has a dynamically

• averaged value between complex 1(LysOMe)2 and free LysOMe. This interpretation is supported by an experiment with an excess of LysOMe (Figure 4e). In [LysOMe + 1(LysOMe)2]MeOH mixture the diffusion coefficient for the LysOMe component exhibits a considerably higher value than in [1(LysOMe)2]MeOH that

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

• smaller size of 6 and its correspondingly higher diffusion coefficient, which results in faster transport to the Au surface and accordingly enhanced surface coverages. Thus, even low decay rates of 1a may lead to sufficiently high concentrations of 6 for obtaining mixed adlayers. By varying the

Complexation of 2,6-helic[6]arene and its derivatives with 1,1′-dimethyl-4,4′-bipyridinium salts and protonated 4,4'-bipyridinium salts: an acid–base controllable complexation

• Jing Li,
• Qiang Shi,
• Ying Han and
• Chuan-Feng Chen

Beilstein J. Org. Chem. 2019, 15, 1795–1804, doi:10.3762/bjoc.15.173

• complex H1·G1 was obtained by vapor diffusion of isopropyl ether into acetone. As shown in Figure 4, G1 was encapsulated in the cavity of H1 to form a 1:1 complex, in which G1 is distorted by the dihedral angle between the pyridinium rings of 33.19°. There exist multiple CH···π interactions between the

• diffusion of isopropyl ether into a chloroform/acetone 1:1 (v/v) solution of the 1:1 mixture of H3 and G1, we only obtained a single crystal of H3 instead of the host–guest complex. The steric hindrance of the n-butoxy groups in H3 (Supporting Information File 1, Figure S90) might lead to weak complexation

• of H3 with the tested guests in solution. However, we obtained a single crystal of complex H5·G1 by vapor diffusion of isopropyl ether into an acetone solution. As shown in Figure 5, we found that G1 was encapsulated in the cavity of H5 to form a 1:1 complex, and the complex molecules are stacked

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

• level may arise from the overall size of the molecule BOD-TTPA-alk that displays 4 alkyl chains and 2 ethylene glycol chains. The bigger size of BOD-TTPA-alk can eventually prevents its diffusion through all the pores of the TiO2 layer or decreases the density of grafted molecules due to steric

An azobenzene container showing a definite folding – synthesis and structural investigation

• Abdulselam Adam,
• Saber Mehrparvar and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2019, 15, 1534–1544, doi:10.3762/bjoc.15.156

• cyclopeptides are connected by two azobenzene bridges. A light-induced switching process leads to a spatially directed collapse of the container which can be detected by an increase of the diffusion coefficient of the molecule. Results and Discussion Synthesis of the chiral foldable container For the design of

• different macrocycles perform a definite clockwise rotation to the other caused by irradiation with UV light and a counterclockwise rotation when the compound is exposed to visible light. The spatial change of the container 10 caused by the switching process could have an impact on the size of the diffusion

• coefficient of the compound. To examine this, DOSY spectra of the container 10 after synthesis and after irradiation with light of the wavelength λ = 365 nm were recorded (Figure 8). Please note, that a change in the geometry of a switch need not result in a change of the size of the diffusion coefficient

Introduction of an isoxazoline unit to the β-position of porphyrin via regioselective 1,3-dipolar cycloaddition reaction

• Xiujun Liu,
• Xiang Ma and
• Yaqing Feng

Beilstein J. Org. Chem. 2019, 15, 1434–1440, doi:10.3762/bjoc.15.143

• linked to the porphyrin is still elusive. Later, a single crystal of 3a was obtained by diffusion of n-hexane to the solution of 3a in CHCl3 at 23 °C. The structure of 3a was unambiguously established by single-crystal X-ray diffraction analysis. Compound 3a crystallized in the monoclinic with space

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• heterotriacene DST 3 were obtained by diffusion of n-hexane into a solution of DST 3 in dichloromethane. Triacene DST 3 crystallized in the monoclinic space group P21/n with four equivalent molecules in the unit cell (a = 6.02748(19), b = 10.6662(3), c = 12.9279(4) Å; α = 90°, β = 96.747(3)°, γ = 90°) resulting

• crystal structure analysis. XRD plots of DST 2 and DSS 4 showed strong diffusion scattering vs signal intensity which we assign to a high degree of amorphous phases. The crystallite sizes determined were quite similar for 1, 2, and 3 (66 nm, 76 nm, and 72 nm), respectively, except for DSS 4 which were

• relatively large shifts of the peak potentials with increasing scan rate, which are due to reduced diffusion of counter ions through the film, hinder the exact determination of redox potentials and trends among the derivatives of the series. Nevertheless, onset potentials, which reflect the starting

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• (Supporting Information File 1, Figure S29) showing a single species with a diffusion coefficient of 2.43 × 10−10 m2s−1. The thus derived molecular radius of 21.7 Å is in very good agreement with the computed r = 21.5 Å (DFT, see Supporting Information File 1, Figure S31). Rectangle 5 was also characterized

• :1) afforded complex 6 = [Cu2(1)(2)(4)]2+ as the exclusive product at room temperature. A single diffusion coefficient in the 1H DOSY NMR (D = 4.40 × 10−10 m2s−1) as well as a single set of signals in the 1H NMR spectrum provided evidence of high purity. The experimental radius of 12.0 Å reflects the

Bambusuril analogs based on alternating glycoluril and xylylene units

• Tomáš Lízal and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2019, 15, 1268–1274, doi:10.3762/bjoc.15.124

• of one glycoluril unit and methine protons of the second glycoluril unit. The monocrystals of 1b suitable for X-ray analysis were obtained upon slow diffusion of diisopropyl ether into the solution of 1b in dichloromethane and benzene. The X-ray structure features Cs symmetry (Figure 5), which is in

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

• diffusion model are used to evaluate adsorption kinetics behavior (the equations of the three models are given in Supporting Information File 1). According to the experimental data, the adsorption kinetic data of PCL and PCL/CB[7] nanofibrous membranes fitting by the above three adsorption kinetics models

• are listed in Table S3 (Supporting Information File 1). As can be seen the correlation coefficients (R2) of all nanofibrous membranes in the pseudo-second-order kinetic model are higher than those of the pseudo-first-order kinetic model and the intraparticle diffusion model, indicating that the

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

• accumulated during the oxidation of PDCPD. The peak value of heat flux is slightly lower than that given in [27], which is explained by the slower diffusion of oxygen into the polymer film from air and the lower temperatures of the oxidation of thin PDCPD films in this study. In our opinion, the peak at 80 °C

• observable rate at low temperatures. In a kinetic mode, the polymer oxidation rate is limited by the kinetic steps of the chain process, indicating that oxygen is quickly transferred from the gaseous phase into a polymer (macro-diffusion) and does not limit the process rate. Otherwise, when oxygen is slowly

• supplied into the sample, the process rate is limited by the diffusion, and the oxidation takes place in a diffusion mode. The reaction kinetics is consecutive and hence, it is characterized by a wide range of rate constants and can be described by the following equation: where the first element on the

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• oxidation is only a net 2 electron process. Previous research shows that the rate of radical trapping by molecular iodine nears diffusion control, similar to that of diatomic oxygen [68][69][70]. This process of radical trapping was probed through the pyrolysis of tert-butyl 2-(naphthalen-1-yl

Synthesis and SAR of the antistaphylococcal natural product nematophin from Xenorhabdus nematophila

• Frank Wesche,
• Hélène Adihou,
• Thomas A. Wichelhaus and
• Helge B. Bode

Beilstein J. Org. Chem. 2019, 15, 535–541, doi:10.3762/bjoc.15.47

• hydrophobicity influences the passive membrane diffusion and therefore might influence how the compounds get to their actual target [30]. Moreover, a specific minimal size of the cyclic moiety must be fulfilled as, e.g., 2 with a phenyl moiety is less active in vitro. Conclusion Despite their lower bioactivities

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• example of “in water” metathesis with a heterogenous catalytic system. Pauly et al. used alginate beads as a matrix to encapsulate the G-II catalyst for the RCM of substrate 31 and 33 (Scheme 7) [44]. Alginate amide beads perform best in neat water as they facilitate the diffusion of hydrophobic

• leader sequence to the N-terminus of streptavidin (Sav) allowed the secretion and assembly of functional tetrameric Sav in the periplasm of E. coli. The passive diffusion of the biotinylated Hoveyda–Grubbs catalyst 60 through the outer membrane of E. coli containing Sav in its periplasm then affords the

New standards for collecting and fitting steady state kinetic data

• Kenneth A. Johnson

Beilstein J. Org. Chem. 2019, 15, 16–29, doi:10.3762/bjoc.15.2

• each parameter. To limit the number of variables, we lock three of the parameters at reasonable values to reduce the model to only two unknowns. For example, we can modify the model to mimic rapid equilibrium binding. To do so, we use a conservative estimate for diffusion-limited substrate binding (k1

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• (E. coli) [47]. The recombinant cells were incubated with a biotinylated GH-type catalyst Ru-3 that reaches the target protein via diffusion through the outer membrane (Scheme 4). Characterization of this whole-cell system included ICP analysis. Whole-cells containing Sav showed an approximately

Synthesis of a leopolic acid-inspired tetramic acid with antimicrobial activity against multidrug-resistant bacteria

• Luce Mattio,
• Loana Musso,
• Leonardo Scaglioni,
• Andrea Pinto,
• Piera Anna Martino and
• Sabrina Dallavalle

Beilstein J. Org. Chem. 2018, 14, 2482–2487, doi:10.3762/bjoc.14.224

• agar plates (Tryptic Soy Agar plus 5% defibrinated sheep blood, Microbiol, Italy) to obtain pure cultures [29]. The isolated colonies were used to assess the phenotypic profile of antimicrobial resistance. For this purpose, the Kirby Bauer disk diffusion method was used in accordance to Clinical

Coordination-driven self-assembly of discrete Ru₆–Pt₆ prismatic cages

• Aderonke Ajibola Adeyemo and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2018, 14, 2242–2249, doi:10.3762/bjoc.14.199

• calculated from the Stokes–Einstein equation using the diffusion coefficients (D) obtained from the DOSY NMR experiments. The obtained values of D from the experiment are −9.631 log (m2 s−1) for 3a and −9.567 log (m2 s−1) for 3b, respectively. The calculated hydrodynamic radii (rH) of 3a and 3b are 15.57 Å

Dynamic light scattering studies of the effects of salts on the diffusivity of cationic and anionic cavitands

• Anthony Wishard and
• Bruce C. Gibb

Beilstein J. Org. Chem. 2018, 14, 2212–2219, doi:10.3762/bjoc.14.195

• fully screened [21][22][23]. Figure 2 shows the effects of the different salts on the observed size of 1. The reported hydrodynamic diameters were calculated using the Stokes–Einstein equation (Equation 1), which assumes host 1 is a spherical particle, where D is the diffusion constant, kb is the