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

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• by diffusion of n-hexane into CH2Cl2 solution [53], but only gave a very brief description of the molecular structure. The Ar3Bi compound (C6H3-t-Bu2-3,5)3Bi (4) was prepared with a yield of 73% following the Grignard route, with the intention to study the influence of very bulky substituents

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• ). In general, if a molecule is to participate in a reaction in the S1 state, its τf must be greater than 1 ns; N.B. the diffusion rate constant (kdiff) is ≈1–2 × 1010 s−1. The fluorescence quantum yield (Φf) is another key parameter to consider when determining whether the S1 state of a molecule is

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• materials science, but its use in supramolecular chemistry is so far very rare [60][61][62][63][64]. It can be applied to investigate translational and rotational diffusion of supramolecules as well as exchange kinetics. To demonstrate the compatibility of the new BODIPY dyes with FCS, we have determined

• the diffusion coefficient of the 2•CB7 complex in comparison to the free 2 dye. FCS autocorrelation curves (Figure 6) were analysed to obtain the diffusion times tdiff of 2 and the 2•CB7 complex and then converted into diffusion coefficients D using the reported standard rhodamine 6G (D = 2.80 × 10−6

• in 10 mM citrate buffer in 30% (v/v) ACN in water, pH 3.1. FCS autocorrelation curves obtained with 10 nM 2 in the absence (red fitted line) and presence (blue fitted line) of 100 µM CB7 at pH 1.5 in 30% (v/v) ACN in water. The fitted diffusion times for the free dye and the complex were 54.1 and

Synthesis and characterization of π–extended “earring” subporphyrins

• Haiyan Guan,
• Mingbo Zhou,
• Bangshao Yin,
• Ling Xu and
• Jianxin Song

Beilstein J. Org. Chem. 2018, 14, 1956–1960, doi:10.3762/bjoc.14.170

• the metal does not change the antiaromatic pathways in 3. Fortunately we obtained single crystals of 3Pd from its CH2Cl2/CDCl3/MeOH solution via vapor diffusion. All of the bond lengths were carefully measured based on the diffraction results (Figure 4). We found that despite all peripheral C–C bond

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• excited state lifetime of conjugate 9 as function of the concentration of guanosine monophosphate (GMP, Figure 4). Stern–Volmer analyses indicate that a dynamic quenching is occurring, with a quenching rate close to the diffusion limit (kQ = 5.6 108 M−1s−1 in intensity and kQ = 5.3 108 M−1s−1 in lifetime

Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• compounds D-N

  NH, 4, 5, 7–9 (2.5 or 5 mM in DMSO-d6 at 298 K on 500 MHz timescale) were acquired by means of the ledbpgp2s pulse sequence. The diffusion time (Δ) ranged from 150 to 220 ms and the gradient pulse length (δ) ranged from 1.7 to 1.9 ms. The size of the raw data set was 32 × 16 k. The gradient

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• evaluated by a paper-disc agar diffusion method described in our previous study [40]. Flexibacter maritimus medium (0.5% peptone and 0.05% yeast extract in sea water) solidified with 10% agar was used to test against T. maritimum. Structures of compounds 1–8. Key COSY (bold line) and HMBC (arrow