Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• an excess amount of NaBH4 as the reducing reagent [45]. In our study, the process of the catalytic reaction was readily followed as the color of the solution turned from yellow to colorless. Both the reactants and products are easily monitored by UV–vis spectroscopy without any formation of

• aqueous NaBH4 solution (6.87 mM, 2.80 mL) were added in the quartz cuvette. Then, the AgNPs/SugPOP-1 composite (1.0 mg/mL, 0.10 mL) suspended in deionized water was subsequently added to the above solution and the reaction progress monitored by UV–vis spectroscopy. The absorption spectra were measured at

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• thio-amphiphilic linker to impart improved solubility and flexibility to the glycosyl-ligand. UV–vis spectroscopy and dynamic light scattering measurements have been exploited to detect at low picomolar concentrations lactose-AuNP, mannose-AuNP and GlcNAc-AuNP interactions with their cognate lectins

• glycoprobe interact with a microplate displaying AFP-L3, LcA strongly bind to AFP-L3 releasing from the supramolecular glycoprobe GAuNPs in a concentration which can be measured via UV–vis spectroscopy. Chiodo et al. [84] gave their contribution in the development of early stage cancer or pathogen diagnosis

• indicative of the successful binding [85]. In this field, a naturally occurring sialylglycopeptide extracted from egg yolks was converted into a thiol-terminated molecule and grafted on AuNPs, to develop a gold-based sensor for influenza virus detection, using both UV–vis spectroscopy and dynamic light

Interactions between shape-persistent macromolecules as probed by AFM

• Johanna Blass,
• Jessica Brunke,
• Franziska Emmerich,
• Cédric Przybylski,
• Vasil M. Garamus,
• Artem Feoktystov,
• Roland Bennewitz,
• Gerhard Wenz and
• Marcel Albrecht

Beilstein J. Org. Chem. 2017, 13, 938–951, doi:10.3762/bjoc.13.95

• the host polymer 8 as a function of the concentration of both guests 9 and 10 (Scheme 2) was determined by UV−vis spectroscopy using the extinction coefficient ε of 8 (14,800 M−1 cm−1) at 425 nm. A more detailed description of the solubility measurements is presented in Supporting Information File 1

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• experimental values obtained by UV–vis spectroscopy. Here it is observed that both the HOMO–LUMO values and the electronic transition wavelengths of the polymers showed promising results for OPV applications. The HOMO–LUMO energy levels of the polymers were determined by cyclic voltammetry, using non-aqueous

• studied by UV–vis spectroscopy. The absorption spectra were obtained in chlorobenzene solution (Figure 4). All polymers showed a broad absorption in the lower energy region (450–650 nm) due to the intramolecular charge transfer (ICT) through the backbone of polymers and another broad peak in the higher

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

• Srikala Pangannaya,
• Neethu Padinchare Purayil,
• Shweta Dabhi,
• Venu Mankad,
• Prafulla K. Jha,
• Satyam Shinde and
• Darshak R. Trivedi

Beilstein J. Org. Chem. 2017, 13, 222–238, doi:10.3762/bjoc.13.25

• melting point apparatus in open capillaries. Infrared spectra were recorded on a Bruker alpha FTIR spectrometer. UV–vis spectroscopy was performed with an Analytik Jena Specord S600 spectrometer in a standard 3.0 mL quartz cell with 1 cm path length. The 1H NMR spectra were recorded on Bruker Ascend (400

Efficient access to β-vinylporphyrin derivatives via palladium cross coupling of β-bromoporphyrins with N-tosylhydrazones

• Vinicius R. Campos,
• Ana T. P. C. Gomes,
• Anna C. Cunha,
• Maria da Graça P. M. S. Neves,
• Vitor F. Ferreira and
• José A. S. Cavaleiro

Beilstein J. Org. Chem. 2017, 13, 195–202, doi:10.3762/bjoc.13.22

• , confirming the molecular formula of these derivatives. All the new porphyrins 3a–c were also characterized by UV–vis spectroscopy, showing the typical profile of the Zn(II) complex of meso-tetraarylporphyrins, with a Soret band at ca. 420 nm and two Q bands between 549 and 586 nm (See Supporting Information

3D printed fluidics with embedded analytic functionality for automated reaction optimisation

• Andrew J. Capel,
• Andrew Wright,
• Matthew J. Harding,
• George W. Weaver,
• Yuqi Li,
• Russell A. Harris,
• Steve Edmondson,
• Ruth D. Goodridge and
• Steven D. R. Christie

Beilstein J. Org. Chem. 2017, 13, 111–119, doi:10.3762/bjoc.13.14

• place on the chip heater of a FlowSyn system by a metal clip. The system was allowed to reach temperature with solvent pumping throughout the system, before switching to a reagent flow. The product from each optimisation point was collected and analysed via UV–vis spectroscopy at a wavelength of 330 nm

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• rich and more complicated phase space than indicated by simple thermal analysis. For BQR, variable temperature UV–vis spectroscopy mapped the transmitted light variations that accompany the phase change noted in the POM studies of BQR. We are currently studying the structural changes occurring in thin

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• recorded using a Perkin Elmer FTIR spectrometer. Melting points were obtained using a Gallenkamp melting point apparatus and are uncorrected. Elemental analysis was conducted by the Durham University departmental service using an Exeter Analytical CE-440 analyser. UV–vis spectroscopy was conducted using a

Amidofluorene-appended lower rim 1,3-diconjugate of calix[4]arene: synthesis, characterization and highly selective sensor for Cu²⁺

• Rahman Hosseinzadeh,
• Mohammad Nemati,
• Reza Zadmard and
• Maryam Mohadjerani

Beilstein J. Org. Chem. 2016, 12, 1749–1757, doi:10.3762/bjoc.12.163

• , Figures S1–S11). General procedure for UV–vis experiments The evaluation of cation-ligand interaction was performed with UV–vis spectroscopy. The UV–vis measurement of receptor L in CH3CN exhibited three absorption peaks at 282, 290, and 314 nm. Furthermore, the variation of UV–vis spectra was monitored

• color change from colorless to purple, which could be observed by the naked eye. The selectivity of receptor L towards Cu2+ was precisely assessed by UV–vis spectroscopy during titration with different concentrations of Cu2+ from 0 to 100 equivalents in CH3CN. In the absence of Cu2+ ions, the ligand L

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• ). Due to the strongly graduated reactivity of DFA, mono-functionalization is feasible, accompanied by a visible color change from yellow to red. This feature allows a reaction control with the naked eye and also with, e.g., UV–vis spectroscopy. The following reaction of DFA-substituted polymer 5 with

• the anthraquinone dye [44]. Thus, this reaction can also be followed with the naked eye. Furthermore, the conversion of oligomer 6 was verified with UV–vis spectroscopy (Figure 2). Accordingly, the different UV–vis spectra (Figure 2) of DFA, oligomer 5 and the disubstituted anthraquinone dye in 6

• can easily be monitored with UV–vis spectroscopy as well as with the naked eye. This work contributes to the increasing area of α-alkylation reactions of N-vinyl lactams and the subsequent application of the so obtained compounds to the synthesis of functionalized oligomers. Chemical structure of

On the mechanism of imine elimination from Fischer tungsten carbene complexes

• Philipp Veit,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

• mechanistic studies to the formation of imine E-3 are performed by NMR, IR and UV–vis spectroscopy and liquid injection field desorption ionization (LIFDI) mass spectrometry as well as by trapping experiments for low-coordinate tungsten complexes with triphenylphosphane. W(CO)5(E-2) decays thermally in a

• pentacarbonyl tungsten complex W(CO)5(E-2) was investigated by density functional theory methods and mechanistic experimental studies (NMR, IR, UV–vis spectroscopy, FD mass spectrometry, kinetic studies, trapping of intermediates). All available data support the initial dissociation of a CO ligand to give the

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

• Yongsheng Chen,
• Li Wang,
• Haojie Yu,
• Zain-Ul-Abdin,
• Ruoli Sun,
• Guanghui Jing,
• Rongbai Tong and
• Zheng Deng

Beilstein J. Org. Chem. 2016, 12, 939–949, doi:10.3762/bjoc.12.92

• and characterized by 1H NMR and GPC. It was observed that the star-like HBPS-g-PDMAEMA formed aggregates in aqueous solution. The influence of polymer concentration, ionic strength and pH value on the aggregates in aqueous solution was investigated by using UV–vis spectroscopy and DLS analysis. The

• solutions were studied by UV–vis spectroscopy as shown in Figure 9B. The standard curve of absorbance at 520 nm of NR in dioxane exhibits an excellent linear relationship of which R2 is 0.99. By using the standard curve, the concentration of NR in each sample solution can be calculated. From calculation and

Separation and identification of indene–C₇₀ bisadduct isomers

• Bolong Zhang,
• Jegadesan Subbiah,
• David J. Jones and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

• configuration were deduced using a variety of analytical techniques including 1H and 13C NMR and UV–vis spectroscopy. The electrochemical properties and the organic solar cell device performance were investigated for fractions where a reasonable quantity of sample could be isolated. Keywords: chromatographic

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• properties of the monomers were investigated by NMR and UV–vis spectroscopy as well as density functional theory (DFT) calculations. Results and Discussion Synthesis Methyl linker: Synthesis of 3-(2,5-dimethoxybenzyl)-1H-pyrrole (3a) For our target compound 3-(2,5-dimethoxybenzyl)-1H-pyrrole (3a), we

• during the hydrogenation reaction, since unprotected pyrrole is known to be far less stable [25]. After desilylation by TBAF, 3-(2,5-dimethoxyphenethyl)-1H-pyrrole (3b) was obtained in a total yield of 36% over five steps from 8. Electronic properties: Evidence from NMR spectroscopy, UV–vis spectroscopy

Polydisperse methyl β-cyclodextrin–epichlorohydrin polymers: variable contact time ¹³C CP-MAS solid-state NMR characterization

• Isabelle Mallard,
• Davy Baudelet,
• Franca Castiglione,
• Monica Ferro,
• Walter Panzeri,
• Enzio Ragg and
• Andrea Mele

Beilstein J. Org. Chem. 2015, 11, 2785–2794, doi:10.3762/bjoc.11.299

• aqueous phase was analyzed by UV–vis spectroscopy (Perkin-Elmer lambda 2S spectrophotometer). X-ray powder diffraction in the 2θ range of 4.7–40° (step size 0.02°; time per step 0.04 s, slits 0.6–8 mm, 30 KV × 10 mA, PSD 3) were collected on a Bruker AXS D2 Phaser diffractometer equipped with LinxEye

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• shown by UV–vis spectroscopy (Figure 2). This rate is comparable to that observed previously with the analogous complex 2, for which a photoreduction quantum yield close to unity has been determined in THF [14]. Because of such a high efficiency, the photoreduction proceeded well under direct sunlight

• (Scheme 3), precluded the use of UV–vis spectroscopy to quantitatively analyze the reductive process. For such an analysis, EPR spectroscopy was thus employed to assess the extent of copper reduction. In Figure 3, the EPR spectra of solutions of 1 (d9, S = 1/2) recorded by irradiating the samples directly

• in the probe at room temperature are presented. Control experiments conducted in THF and aqueous solutions of 1 (Figure 3a and b, respectively), confirmed the results gathered by UV–vis spectroscopy, i.e., fast reduction in THF and essentially no reduction in water. In water solution, the EPR spectra

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• fluorescence spectra of these porphyrin–xanthone dyads. Keywords: 1,3-dipolar cycloaddition; fluorescence; synthesis; triazoloporphyrin-xanthone dyads; UV–vis spectroscopy; Introduction In the past few decades, porphyrin macrocycles have emerged as a unique class of heterocyclic compounds and as most

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene: the effect of planarisation on charge transport properties

• Rupert G. D. Taylor,
• Joseph Cameron,
• Iain A. Wright,
• Neil Thomson,
• Olena Avramchenko,
• Alexander L. Kanibolotsky,
• Anto R. Inigo,
• Tell Tuttle and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1148–1154, doi:10.3762/bjoc.11.129

• and electrochemical properties of compounds 1 and 2 have been measured by UV–vis spectroscopy and cyclic voltammetry and the results compared with density functional theory (DFT) calculations to confirm the observed properties. Organic field effect transistor (OFET) devices fabricated from 1 and 2

• the synthesis of a half-unit and a final triethyl phosphite mediated homo-coupling. The resultant compounds, 1 and 2, were fully characterised and their optical and electrochemical properties elucidated via UV–vis spectroscopy and cyclic voltammetry, and explained in conjunction with DFT level

• –vis spectroscopy using dichloromethane (DCM) as the solvent (Figure 2). The obtained spectrum of compound 1 shows a maximum absorption at 380 nm and two less intense peaks at 308 nm and 274 nm. The most intensive absorption peak of 2 shows a 7 nm bathochromic shift compared to 1 and this main peak

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

• Yuchun Ren,
• Bin Wang and
• Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

• designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial

Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency

• Anna K. Ciuk and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 668–674, doi:10.3762/bjoc.11.75

• photocycloaddition leading to two isomeric cis–syn- and two trans–syn-[2 + 2] photocycloaddition products. In addition, also an anti product seems to form as five (not four) H-1 signals are seen in the 1H NMR spectrum. The photocycloaddition of 7 can also be observed by UV–vis spectroscopy. Upon irradiation, the

• glycothymine branches in 13 and 14 are sterically more hindered than the thymine branches in 7 and 8. Again UV–vis spectroscopy further underlines the dimerization success as the absorption maximum at 270 nm disappears and mass spectrometry supports intramolecular photocycloaddition only (cf. Supporting

Fluoride-driven ‘turn on’ ESPT in the binding with a novel benzimidazole-based sensor

• Kai Liu,
• Xiaojun Zhao,
• Qingxiang Liu,
• Jianzhong Huo,
• Bolin Zhu and
• Shihua Diao

Beilstein J. Org. Chem. 2015, 11, 563–567, doi:10.3762/bjoc.11.61

• was 8.79 × 105 M−1, which was bigger than that obtained from UV–vis spectroscopy. This suggested the enhancement of the phenolic OH acidity by the photoexcitation [2][11][12][13][14][15]. Moreover, fluoride-dependent fluorescent intensity at 376 nm displayed an excellent linearity (R = 0.9880) in the

Properties of cationic monosubstituted tetraalkylammonium cyclodextrin derivatives – their stability, complexation ability in solution or when deposited on solid anionic surface

• Martin Popr,
• Sergey K. Filippov,
• Nikolai Matushkin,
• Juraj Dian and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2015, 11, 192–199, doi:10.3762/bjoc.11.20

• methods were also tested, but their usability was found to be lower than ITC. For example 1H NMR spectroscopy [34] requires relatively high concentrations of the guest and host molecules, which are often impossible to achieve due to the poor solubility in aqueous media. Conventional UV–vis spectroscopy

• extracted from cavities by MeOH (1 × 3 mL). The amount of complexed guest was quantified by UV–vis spectroscopy of the MeOH extracts against the blank sample which consisted of Nafion® 117 with no deposited PEMPDA-β-CD. This method proved to be very useful and simple tool for determination of the amount of

• surface of polymeric Nafion® 117 membrane via electrostatic interactions. Deposition kinetics and coverage of the surface were determined by ELSD. Finally, the ability of the CD derivatives bound to the solid surface to encapsulate aromatic compounds from aqueous solution was measured by UV–vis

Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer

• Francesco Trotta,
• Fabrizio Caldera,
• Roberta Cavalli,
• Andrea Mele,
• Carlo Punta,
• Lucio Melone,
• Franca Castiglione,
• Barbara Rossi,
• Monica Ferro,
• Vincenza Crupi,
• Domenico Majolino,
• Valentina Venuti and
• Dominique Scalarone

Beilstein J. Org. Chem. 2014, 10, 2586–2593, doi:10.3762/bjoc.10.271

• between SF and the branched β-CD polymer was further supported by UV–vis spectroscopy. The UV spectra of SF in the absence and presence of increasing amounts of polymer are shown in Figure 7. A decrease of absorbance was observed for the UV band of FS (490 nm) and an increase of absorbance of a new band

Host–guest-driven color change in water: influence of cyclodextrin on the structure of a copper complex of poly((4-hydroxy-3-(pyridin-3-yldiazenyl)phenethyl)methacrylamide-co-dimethylacrylamide)

• Nils Retzmann,
• Gero Maatz and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2480–2483, doi:10.3762/bjoc.10.259

• -yldiazenyl)phenethyl)methacrylamide-co-dimethylacrylamide) and its reversible optical and complex-forming properties due to copper and cyclodextrin (CD) interactions. Color changing effects are characterized by UV–vis spectroscopy and the supramolecular behavior is investigated by dynamic light scattering

• by the addition of γ-CD [12]. Subsequent UV–vis spectroscopy allowed us to characterize the above mentioned color changes in the diluted state (Figure 2). Hereby a bathocromic shift of the peak maximum at 380 nm to 475 nm of 7 was observed due to complexation with CuSO4 which is reversible after γ-CD