Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

• Lukas J. Patalag and
• Daniel B. Werz

Beilstein J. Org. Chem. 2016, 12, 2739–2747, doi:10.3762/bjoc.12.270

• chain [15]. Their slim shape mimics the natural geometry of a saturated hydrocarbon chain and should therefore only lead to minimal disturbances [16]. Nevertheless, we found that their stability with respect to both, oxygen and strong laser beams, is relatively low. The design of novel fluorescent fatty

• = 412 nm (three double bonds) which matches the requirements for modern laser equipments to trigger efficient excitation. All three variants show remarkably large Stokes shifts ranging from 4900–5700 cm−1 and fluorescence quantum yields in the range of 0.18 to 0.44. As a set of geometrically similar

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• min–1 for 120 min, weight = 780 g (jar, cap, and balls). Temperatures were measured using a Lafayette TRI-88 no-contact thermometer, built-in laser pointer, with ±2 °C reading accuracy, distance to spot size = 8:1, measuring distance 18–23 cm. The measurement matrix formed "a five on a die", two

Determination of the absolute stereostructure of a cyclic azobenzene from the crystal structure of the precursor containing a heavy element

• Reji Thomas and
• Nobuyuki Tamaoki

Beilstein J. Org. Chem. 2016, 12, 2211–2215, doi:10.3762/bjoc.12.212

• references. Experimental All solvents and chemicals were obtained from commercial sources and used without further purification, unless otherwise stated. NMR (1H and 13C) spectra were recorded with a JEOL ECX 400 spectrometer using tetramethylsilane as an internal standard. Matrix-assisted laser desorption

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• calorimetry (DSC) measurements: ≈2 mg material was used for the DSC experiments, which was conducted under nitrogen at a scan rate of 10 °C/min with a TA DSC-Q20 instrument. Raman spectra were measured using a Renishaw inVia Raman spectrometer with 785 nm diode laser excitation. Laser power at the sample was

• temperature of the sample. For room temperature measurements the total laser exposure time was 25 s, the exposure time for temperature dependent spectra was 10 s. Starting from room temperature, the sample was heated at 10 °C/min to 300 °C, then cooled at the same rate. The temperature was held for 1 minute

Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

• Vincent M. Rotello

Beilstein J. Org. Chem. 2016, 12, 1638–1646, doi:10.3762/bjoc.12.161

• notion of taking some cells, putting in nanoparticles, and then throwing them in the matrix-assisted laser desorption ionization (MALDI) mass spectrometer without matrix. Quite surprisingly, all the student could see was the ligand on the particle – with essentially no signal from all of the rest of the

• stuff found in cells [68]. This was the start of a collaboration that continues to this day, where we have used laser desorption ionization (LDI) to characterize ligands on particles [69][70], supramolecular chemistry in cells [71], track NPs in fish [72] and plants [73], and to image NPs in animal

Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• photoabsorption properties. Experimental General methods Matrix-assisted laser desorption ionization time-of-flight (MALDI–TOF) mass spectra were collected on a Bruker Daltonics Autoflex III spectrometer using dithranol as the matrix. Elemental analysis was carried out using a YANACO CHN coder MT-6

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• on a JASCO FT/IR-4100 spectrometer in the range from 4000 to 600 cm−1. MALDI–TOF mass spectra were measured on a Shimadzu/Kratos AXIMA-CFR mass spectrometer equipped with nitrogen laser (λ = 337 nm) and pulsed ion extraction, which was operated in a linear-positive ion mode at an accelerating

Artificial Diels–Alderase based on the transmembrane protein FhuA

• Hassan Osseili,
• Daniel F. Sauer,
• Klaus Beckerle,
• Marcus Arlt,
• Tomoki Himiyama,
• Tino Polen,
• Akira Onoda,
• Ulrich Schwaneberg,
• Takashi Hayashi and
• Jun Okuda

Beilstein J. Org. Chem. 2016, 12, 1314–1321, doi:10.3762/bjoc.12.124

• (polyethylene-polyethylene glycol), SDS (sodium dodecyl sulfate), TEV (Tobacco Etch Virus), MALDI–TOF–MS (matrix-assisted laser desorption/ionisation and time-of-flight mass spectrometry), FhuAΔCVFtev (FhuA Δ1-159_C545_V548_F501_tev), CD (circular dichroism), ESI-MS (electrospray ionization-mass spectrometry

Biradical vs singlet oxygen photogeneration in suprofen–cholesterol systems

• Fabrizio Palumbo,
• Francisco Bosca,
• Isabel M. Morera,
• Inmaculada Andreu and
• Miguel A. Miranda

Beilstein J. Org. Chem. 2016, 12, 1196–1202, doi:10.3762/bjoc.12.115

• with reduction of the BZT chromophore. Dyads 1 and 2 were efficiently photolyzed under anaerobic conditions, whereas 3 was markedly unreactive. Interestingly, 2 was significantly more photoreactive than 1 indicating a clear stereodifferentiation in the photochemical behavior. Laser flash photolysis

• ammonium molybdate reagent. The residues were purified through silica gel 60 (0.063–0.2 mm). Exact mass was obtained by Waters ACQUITY™ XevoQToF spectrometer. Laser flash photolysis (LFP) measurements As described in [17], a pulsed Nd:YAG laser was used for the excitation at 355 nm. The single pulses were

• of ~10 ns duration, and the energy was from 10 to 1 mJ/pulse. The LFP system consisted of the pulsed laser, the Xe lamp, a monochromator and a photomultiplier made up of a tube, housing and power supply. The output signal from the oscilloscope was transferred to a personal computer. All experiments

Synthesis of a deuterated probe for the confocal Raman microscopy imaging of squalenoyl nanomedicines

• Eric Buchy,
• Branko Vukosavljevic,
• Maike Windbergs,
• Dunja Sobot,
• Camille Dejean,
• Simona Mura,
• Patrick Couvreur and
• Didier Desmaële

Beilstein J. Org. Chem. 2016, 12, 1127–1135, doi:10.3762/bjoc.12.109

• , have been developed to study the stability of nanoparticles [23]. In this context, Raman spectroscopy is an interesting technique which is based on the detection of scattered laser light upon irradiating the sample. Nevertheless, because of the low intensity of the Raman scattering, efficient in vivo

• confocal Raman microspectroscopy of cells had to wait until laser technology and mathematical image processing have made enough progress [24][25]. In contrast to fluorescence spectroscopy, Raman spectroscopy is label-free, as its scattering effect is unique for a specific molecular structure. Raman spectra

• measurements. Confocal Raman microscopy measurements were performed with a WITec alpha 300R+ (WITec GmbH, Ulm, Germany). The excitation source was a diode laser with a wavelength of 532 nm adjusted to a power of 40 mW before the objective. A confocal pinhole of 50 μm rejected signals from out-of-focus regions

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• identified as piericidin derivatives (e.g., piericidin A1 (1), Figure 3) and the chlorinated indole derivative streptochlorin (2). Imaging analysis based on a combination of laser desorption/ionization (LDI)–time of flight (TOF) mass spectrometry imaging visualized the spatial distribution of the antibiotics

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• entrance via confocal laser scanning microscopy [30]. Several types of dye moiety/CD derivatives have been suggested as "switch on" or "switch off" fluorescent chemical sensors. In these systems, the complexation with a guest molecule allows to enhance or decrease the fluorescence intensity. Two water

Aggregation behavior of amphiphilic cyclodextrins in a nonpolar solvent: evidence of large-scale structures by atomistic molecular dynamics simulations and solution studies

• Giuseppina Raffaini,
• Fabio Ganazzoli and
• Antonino Mazzaglia

Beilstein J. Org. Chem. 2016, 12, 73–80, doi:10.3762/bjoc.12.8

• −1 concentration. The dispersion was centrifuged at 3000 rpm (10 min) to remove dust and air bubbles. Dynamic light scattering (DLS) measurements were carried out on a homemade apparatus by using a duplicated Nd:YAG laser source (λ = 532.0 nm) at a power of 50 mW, at a scattering angle of 90°. The

Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• ]. Nanoparticles containing these self-illuminating molecules enable high sensitivity imaging of deep-tissue target sites in living subjects [40]. A recent spin-off from the squaraine rotaxane project uses homologous croconaine dyes to absorb 800 nm laser light and cleanly convert the energy into heat without

• . Another use for these dyes is as contrast agents for photoacoustic imaging where short laser pulses are converted into sound waves that are detected using an ultrasound scanner. Synthavidin technology While working with the molecular building blocks to make squaraine and croconaine rotaxanes we discovered

Size-controlled and redox-responsive supramolecular nanoparticles

• Raquel Mejia-Ariza,
• Gavin A. Kronig and
• Jurriaan Huskens

Beilstein J. Org. Chem. 2015, 11, 2388–2399, doi:10.3762/bjoc.11.260

• ). Equipment Dynamic light scattering (DLS) Hydrodynamic diameters and zeta potentials were measured on a Zetasizer NanoZS (Malvern Instrument Ltd, Malvern, United Kingdom) at 20 °C, with a laser wavelength of 633 nm and a scattering angle of 173°. High resolution scanning electron microscopy (HR-SEM) All SEM

• chemical shift value, 400 MHz is reported as δ using the residual solvent signal as internal standard at ≈22 °C. Mass spectrometry Mass analysis was done using matrix-assisted laser desorption ionization (MALDI) on a Waters Synapt G1 using 2,5-dihydroxybenzoic acid as the matrix. Microcalorimetric

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• that the adsorption of the CD nanogels at the oil–water interface stabilizes the emulsion. Organization of CD nanogels at the interface To characterize the interfacial structure and to examine the stability of interfacial assembly of the CD nanogels, laser or scanning microscopy observation was

• , which consist of a CD nanogel assembly, were also observed after the removal of toluene (Figure S5, Supporting Information File 1). The layer thickness of the CD nanogel assembly was assessed by a cross-sectional histogram using a laser microscope (Figure 7C). The estimated layer thickness between the

• Information File 1. Dynamic light scattering (DLS) The particle size distribution was measured at 25 °C using DLS6000HL (Otsuka Electronic Co.) equipped with a He-Ne laser (wavelength 632.8 nm). The mean particle diameter was calculated from the diffusion coefficients using the Stokes–Einstein equation. The

Convenient preparation of high molecular weight poly(dimethylsiloxane) using thermally latent NHC-catalysis: a structure-activity correlation

• Stefan Naumann,
• Johannes Klein,
• Dongren Wang and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 2261–2266, doi:10.3762/bjoc.11.246

• up, ranging from 200 000 g/mol to over 400 000 g/mol (Mn). Importantly, in all these cases very high conversion is observed. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–ToF MS) and NMR experiments clearly show that BnOH is incorporated in the resulting PDMS (S1

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• -Lac-β-CyD was found to be associated with U18666A-treated HepG2 cells, higher than TRITC-β-CyD, which is lacking the lactose moiety (Figure 4A,B). Next, we examined the intracellular distribution of TRITC-Lac-β-CyD by confocal laser scanning microscopy (Figure 5). It should be noted that cellular

• fluorescence derived from TRITC and LysoTracker® in U18666A-treated HepG2 cells was detected by confocal laser scanning microscopy. The fluorescence intensities were determined by a BZ-II analyzer (Keyence, Osaka, Japan). Intracellular distribution of cholesterol U18666A-treated HepG2 cells (5 × 104 cells/35

Cross-metathesis of polynorbornene with polyoctenamer: a kinetic study

• Yulia I. Denisova,
• Maria L. Gringolts,
• Alexander S. Peregudov,
• Liya B. Krentsel,
• Ekaterina A. Litmanovich,
• Arkadiy D. Litmanovich,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2015, 11, 1796–1808, doi:10.3762/bjoc.11.195

• goniometer equipped with a HeNe laser (a wavelength of λ = 633 nm, an intensity of 25 mW) as a light source. The scattering angle θ was varied in the range 30–150°. In static experiments, the total scattering intensity was measured. In dynamic experiments, the time cross-correlation function g2 of the

Cathodic hydrodimerization of nitroolefins

• Michael Weßling and
• Hans J. Schäfer

Beilstein J. Org. Chem. 2015, 11, 1163–1174, doi:10.3762/bjoc.11.131

• decomposition, which is similar to the product obtained by hydrogenating dimerization of olefin 4 in [11]. The insolubility and the melting point disagree, however, with compound 3 (n = 1) described in [20]. From the laser desorption ionization (LDI) mass spectrum of 3 it could be presumed that 3 is mainly a

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

• Flavia Pop and
• Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

• TMS. The following abbreviations are used: d, doublet; t, triplet; m, multiplet. MALDI–TOF MS spectra were recorded on a Bruker Biflex-IIITM apparatus, equipped with a 337 nm N2 laser. Elemental analyses were recorded using Flash 2000 Fisher Scientific Thermo Electron analyzer. The starting compounds

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• spectrometry (MS) was performed using Matrix Assisted Laser Desorption Ionization (MALDI); TOF = time-of-flight; FT-ICR = Fourier Transform Ion Cyclotron Resonance. IR spectra were measured using the attenuated total reflectance (ATR) method on diamond. The relative peak intensities in IR spectra are

Terminal lipophilization of a unique DNA dodecamer by various nucleolipid headgroups: Their incorporation into artificial lipid bilayers and hydrodynamic properties

• Emma Werz and
• Helmut Rosemeyer

Beilstein J. Org. Chem. 2015, 11, 913–929, doi:10.3762/bjoc.11.103

• perfusion step using the Ionovation perfusion unit was followed by an incubation step. This procedure was repeated until the brightness of the bilayer stabilized. All confocal imaging and lifetime measurements were performed on a confocal laser scanning microscope (Insight Cell 3D, Evotec Technologies GmbH

• , Hamburg, Germany) equipped with a 635 nm emitting laser diode (LDH-P-635, PicoQuant, Berlin, Germany), a 40× water immersion objective (UApo 340, 40×, NA = 1.15, Olympus, Tokyo, Japan), and an Avalanche photodiode detector (SPCM-AQR-13-FC, Perkin-Elmer Optoelectronics, Fremont, CA, USA). Fluorescence

• irradiation was achieved with an excitation laser power of 200 ± 20 µW directly in front of the objective. Z-direction scans were performed by scanning the confocal laser spot in the X–Y direction with a rotating beam scanner and movement of the objective in the Z direction. The movement in all directions was

Multivalent dendritic polyglycerolamine with arginine and histidine end groups for efficient siRNA transfection

• Fatemeh Sheikhi Mehrabadi,
• Hanxiang Zeng,
• Mark Johnson,
• Cathleen Schlesener,
• Zhibin Guan and
• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 763–772, doi:10.3762/bjoc.11.86

• gel packets with polyplexes, electrophoresis was run in TAE buffer for 45 min at 60 V. The results were visualized under UV illumination. DLS/Zeta The size and zeta potential (ζ) of AAdPG/siRNA polyplexes were measured by a Zetasizer Nano ZS analyzerTM with integrated 4 mW He-Ne laser, λ = 633 nm

• , 500G). GFP fluorescence of transfected cells was measured on a Becton-Dickinson LSR II flow cytometer with argon ion excitation laser. For each sample, data representing 10,000 objects were collected as a list-mode file and analyzed using FACSDivaTM software (Becton Dickinson, version 6.1.3) and the

• bovine serum. Confocal fluorescence spectroscopy was performed at different time points after the transfection. The nuclei were stained with Hoechst 33342 following the standard protocol. The images were acquired using a Zeiss LSM 510 inverted laser-scanning confocal microscope with a 40× numerical

Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• is a piezoelectronic semiconductor with a high exciton binding energy (60 meV) and a wide band-gap (3.37 eV) at room temperature [17][18]. ZnO is therefore employed in (bio-)sensors [19], ultraviolet (UV) light-emitting diodes [20], UV laser diodes [21] and in the field of catalysis [22][23]. ZnO