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Search for "absorption spectroscopy" in Full Text gives 88 result(s) in Beilstein Journal of Organic Chemistry.

Correlation of surface pressure and hue of planarizable push–pull chromophores at the air/water interface

  • Frederik Neuhaus,
  • Fabio Zobi,
  • Gerald Brezesinski,
  • Marta Dal Molin,
  • Stefan Matile and
  • Andreas Zumbuehl

Beilstein J. Org. Chem. 2017, 13, 1099–1105, doi:10.3762/bjoc.13.109

Graphical Abstract
  • using fluorescence microscopy, grazing-incidence angle X-ray diffraction, and infrared reflection–absorption spectroscopy. An increase of the lateral membrane pressure leads to a well-packed layer of the ‘flipper’ mechanophores and a clear change in hue above 18 mN/m. The fluorescent probes had no
  • ][17][18], as well as infrared reflection–absorption spectroscopy (IRRAS) [19]. Results and Discussion Pressure-area isotherm measurements All pressure-area isotherm measurements were performed on Langmuir–Pockels troughs (either a self-made computer-interfaced film balance [20] using the Wilhelmy
  • from monolayer IRRAS experiments. Infrared reflection–absorption spectroscopy (IRRAS) The infrared reflection–absorption was recorded for a monolayer at different surface pressures (see Figures S5, S6, Supporting Information File 1). The positive peak at around 3600 cm−1, indicating a higher intensity
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Published 08 Jun 2017

Sulfamide chemistry applied to the functionalization of self-assembled monolayers on gold surfaces

  • Loïc Pantaine,
  • Vincent Humblot,
  • Vincent Coeffard and
  • Anne Vallée

Beilstein J. Org. Chem. 2017, 13, 648–658, doi:10.3762/bjoc.13.64

Graphical Abstract
  • contact angle (WCA) measurements, Fourier-transform infrared reflection absorption spectroscopy (IRRAS) and X-ray photoelectron spectroscopy (XPS). Keywords: gold surfaces; hydrolysis; IRRAS; reversibility; SAM; sulfamide; XPS; Introduction Self-assembled monolayers (SAMs) have raised considerable
  • gold based on the sulfamide chemistry and to partially regenerate the amino SAM. The surface modification process is studied by water contact angle measurements (WCA), Fourier transform infrared reflection absorption spectroscopy (PM-IRRAS) and X-ray photoelectron spectroscopy (XPS). Results and
  • functional end groups have been prepared in 31% and 47% conversions from readily available aniline-terminated self-assembled monolayers. The resulting sulfamide-derived SAMs were characterized by water contact measurements, Fourier-transform infrared reflection absorption spectroscopy and X-ray photoelectron
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Published 04 Apr 2017

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

  • Qi An,
  • Youssef Hassan,
  • Xiaotong Yan,
  • Peter Krolla-Sidenstein,
  • Tawheed Mohammed,
  • Mathias Lang,
  • Stefan Bräse and
  • Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

Graphical Abstract
  • well as the molecular structures of the reactants used in the described reaction. We repeated the described reaction cycle 20 times to obtain CMPs thin films on functionalized gold wafers. Characterization of CMP thin films We characterized the reaction using infrared reflection absorption spectroscopy
  • ) wafer, coated with 5 nm titanium and 100 nm gold (Au/Ti/Si). The substrates were obtained from Georg-Albert-PVD, Germany and stored under an argon atmosphere prior to use. Infrared reflection absorption spectroscopy (IRRAS): The IRRA-spectra were recorded on a Bruker Vertex 80 purged with dried air. The
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Published 17 Mar 2017

Interactions between photoacidic 3-hydroxynaphtho[1,2-b]quinolizinium and cucurbit[7]uril: Influence on acidity in the ground and excited state

  • Jonas Becher,
  • Daria V. Berdnikova,
  • Darinka Dzubiel,
  • Heiko Ihmels and
  • Phil M. Pithan

Beilstein J. Org. Chem. 2017, 13, 203–212, doi:10.3762/bjoc.13.23

Graphical Abstract
  • . The chemical shifts are given relative to the solvent peak in ppm (DMSO-d6: 1H = 2.50, 13C = 39.5). Absorption spectroscopy: Cary 100 bio spectrophotometer with baseline correction; in quartz cells (10 mm × 10 mm). Emission spectroscopy: Cary Eclipse spectrophotometer at 20 °C; in quartz cells (10 mm
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Published 01 Feb 2017

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

  • Ulrike Kauscher and
  • Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

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  • cyclodextrin vesicle surface. The supramolecular immobilization was monitored by using fluorescence spectroscopy and microscopy and the photochemistry of the squaraine was investigated by using absorption spectroscopy. Keywords: cyclodextrin; host–guest chemistry; photodynamic therapy; self-assembly
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Published 25 Nov 2016

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

Graphical Abstract
  • -substituted oligothiophene π-bridges, the BTxR series of materials, where x = 4 (butyl) and x = 8 (octyl). Thin films of the pure materials have been analysed by UV–vis absorption spectroscopy which indicated that extension of the BXR chromophore through oligothiophene extension and side-chain variation
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Published 02 Nov 2016

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

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  • absorption spectroscopy, we performed in situ Raman spectroscopy measurements, similar to those previously carried out on P3OT and F-P3OT [42] in order to observe the evolution of intramolecular order with temperature, and compare the block copolymers with the polymer blends. The room temperature Raman
  • P3OT/F-P3OT blended film are the temperature dependent Raman spectra unaffected by the presence of P3OT, as is the case in the behavior measured using UV–visible absorption spectroscopy and DSC. In the case of the 2:1 block copolymer, the temperature dependence of the Raman signals attributed to P3OT
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Published 10 Oct 2016

Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

  • Vito Rizzi,
  • Sergio Matera,
  • Paola Semeraro,
  • Paola Fini and
  • Pinalysa Cosma

Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54

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  • techniques such as, UV–visible absorption spectroscopy, FTIR–ATR and 1H NMR with the help of electrochemical analysis were utilized in order to characterize the formation of inclusion complexes between S4TdR and CDs. Among the used techniques, 1H NMR spectroscopy gave the most direct evidence for the
  • inclusion of S4TdR inside the CD cavity [29][30]. In fact, the H3 and H5 atoms of CDs, which are directed towards the interior of the cavity of the CDs showed a significant upfield shift when strong inclusion interactions are present [31][32]. Results and Discussion UV–vis absorption spectroscopy At first
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Published 21 Mar 2016

N-Methylphthalimide-substituted benzimidazolium salts and PEPPSI Pd–NHC complexes: synthesis, characterization and catalytic activity in carbon–carbon bond-forming reactions

  • Senem Akkoç,
  • Yetkin Gök,
  • İlhan Özer İlhan and
  • Veysel Kayser

Beilstein J. Org. Chem. 2016, 12, 81–88, doi:10.3762/bjoc.12.9

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  • against the calculated values of m/z 636.84, 691.84 and 574.95, respectively. Unfortunately, we were unable to yield a proper single crystal from these compounds for X-ray diffraction. Unlike the salts, the metal complexes showed absorbance in UV–vis experiments. Absorption spectroscopy studies The
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Published 15 Jan 2016

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

  • Nicolas Desbois,
  • Sandrine Pacquelet,
  • Adrien Dubois,
  • Clément Michelin and
  • Claude P. Gros

Beilstein J. Org. Chem. 2015, 11, 2202–2208, doi:10.3762/bjoc.11.239

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  • solution of GaCl3 in pyridine and then refluxed for 1.5 h as previously described [28]. Corroles 8a and 8b were prepared and characterized by 1H NMR, HRMS and UV–vis absorption spectroscopy. Different metal ions were introduced inside the porphyrin core 2, namely copper, gallium, indium and manganese. For
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Published 17 Nov 2015

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

  • Awatef Ayadi,
  • Aziz El Alamy,
  • Olivier Alévêque,
  • Magali Allain,
  • Nabil Zouari,
  • Mohammed Bouachrine and
  • Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

Graphical Abstract
  • , Supporting Information File 1) resulting in alternating stacks with a “zig zag” like manner with an angle of rotation of 135.6° (Figure 3). UV–visible absorption spectroscopy The UV–visible absorption spectra of the ligands L1 and L2 were recorded in a mixture of dichloromethane/acetonitrile solution (9/1, v
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Published 07 Aug 2015

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

  • Raúl García,
  • M. Ángeles Herranz,
  • Edmund Leary,
  • M. Teresa González,
  • Gabino Rubio Bollinger,
  • Marius Bürkle,
  • Linda A. Zotti,
  • Yoshihiro Asai,
  • Fabian Pauly,
  • Juan Carlos Cuevas,
  • Nicolás Agraït and
  • Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

Graphical Abstract
  • added (5 equiv), a dark green color developed. UV–vis absorption spectroscopy confirmed the formation of a CT complex (Supporting Information File 1, Figure S1). To ensure the quantitative formation of the CT complex, a more straightforward method compatible with the conductance measurements was
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Published 24 Jun 2015

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

  • Yunfei Wang and
  • Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

Graphical Abstract
  • were also produced as a yellow powder. The electronic properties of TTFVs 5 and 6 as well as their DTF precursors 4 and 7 were investigated by UV–vis absorption spectroscopy. Figure 1 shows the UV–vis absorption spectra of these compounds, in which the maximum absorption wavelengths (λmax) of all the
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Published 03 Jun 2015

Synthesis and characterization of the cyanobenzene-ethylenedithio-TTF donor

  • Sandrina Oliveira,
  • Dulce Belo,
  • Isabel C. Santos,
  • Sandra Rabaça and
  • Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 951–956, doi:10.3762/bjoc.11.106

Graphical Abstract
  • investigated by UV–vis absorption spectroscopy in dichloromethane solution. The UV–vis spectra in DCM (Figure S6 in Supporting Information File 1) showed π–π* transitions typical of TTF donors [21], with an intense absorption band centred at approximately at 231 nm and other weaker bands at 269, 305 and 329 nm
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Published 03 Jun 2015

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

  • Daniel Schöne,
  • Boris Schade,
  • Christoph Böttcher and
  • Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

Graphical Abstract
  • band. UV–vis absorption spectroscopy was applied to monitor the LSPR band of mercaptoundecanoic acid-functionalized gold nanoparticles (Au/MUA) in the presence of the VW05 variants. Peptides at concentrations ranging from 5 to 30 µM, at pH 9, were added to a nanoparticle solution and UV–vis absorption
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Published 15 May 2015

A comparative study of the interactions of cationic hetarenes with quadruplex-DNA forming oligonucleotide sequences of the insulin-linked polymorphic region (ILPR)

  • Darinka Dzubiel,
  • Heiko Ihmels,
  • Mohamed M. A. Mahmoud and
  • Laura Thomas

Beilstein J. Org. Chem. 2014, 10, 2963–2974, doi:10.3762/bjoc.10.314

Graphical Abstract
  • , 70 mM KCl; adjusted with 25 mM KH2PO4 to pH 7.0; sodium cacodylate buffer: 10 mM Na(CH3)2AsO2·3H2O, 10 mM KCl, 90 mM LiCl; pH 7.2–7.3. Equipment Absorption spectroscopy: Varian Cary 100 Bio spectrophotometer; emission spectroscopy: Varian Cary Eclipse; CD spectroscopy: Chirascan CD-spectrometer
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Published 11 Dec 2014

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

  • Clara Orofino-Pena,
  • Diego Cortizo-Lacalle,
  • Joseph Cameron,
  • Muhammad T. Sajjad,
  • Pavlos P. Manousiadis,
  • Neil J. Findlay,
  • Alexander L. Kanibolotsky,
  • Dimali Amarasinghe,
  • Peter J. Skabara,
  • Tell Tuttle,
  • Graham A. Turnbull and
  • Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

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  • these two families were studied in order to determine their suitability as emissive materials in photonic applications. Keywords: absorption spectroscopy; BODIPY; cyclic voltammetry; photoluminescence; star-shaped oligofluorene; Introduction The boron-dipyrromethene (BODIPY) or 4,4-difluoro-4-bora-3a
  • , right) of T-B1. Synthesis of the Y-Bn (n = 1–4) series. Synthesis of the T-Bn (n = 1–4) series. Thermal properties of oligofluorene–BODIPY compounds. Electrochemical data for oligofluorene–BODIPY compounds and HOMO–LUMO gaps calculated from cyclic voltammetry and electronic absorption spectroscopy
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Published 19 Nov 2014

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

  • Diego Cortizo-Lacalle,
  • Calvyn T. Howells,
  • Upendra K. Pandey,
  • Joseph Cameron,
  • Neil J. Findlay,
  • Anto Regis Inigo,
  • Tell Tuttle,
  • Peter J. Skabara and
  • Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

Graphical Abstract
  • characterised by UV–vis absorption spectroscopy in both solution and solid state (drop-cast on ITO) and the corresponding spectra are shown in Figure 3, with the data summarised in Table 2. For comparison, the absorption spectrum of the dithieno-DPP (Figure 4, 11) core in solution is also shown in Figure 3. All
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Published 18 Nov 2014

Aryl substitution of pentacenes

  • Andreas R. Waterloo,
  • Anna-Chiara Sale,
  • Dan Lehnherr,
  • Frank Hampel and
  • Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

Graphical Abstract
  • acetone. UV–vis spectroscopy Aryl pentacenes 3a–k have been studied by UV–vis absorption spectroscopy in CH2Cl2 solutions and as thin films cast from CH2Cl2 onto quartz. Solution-state UV–vis spectra show characteristic absorptions in the high-energy region with a maximum intensity absorption centered at
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Published 28 Jul 2014

Photoswitchable precision glycooligomers and their lectin binding

  • Daniela Ponader,
  • Sinaida Igde,
  • Marko Wehle,
  • Katharina Märker,
  • Mark Santer,
  • David Bléger and
  • Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

Graphical Abstract
  • File 1). Characterization of the photoswitchable properties The photochromic behavior of the newly synthesized AZO-glycooligomers was investigated by UV–vis absorption spectroscopy and ultraperformance liquid chromatography (UPLC). Aqueous solutions of Azo-Gal(1,3)-3 and Azo-Gal(1,3,5)-5 (the compounds
  • solid support followed by on-resin functionalization of alkyne side chains with sugar azide ligands and final cleavage from the support. Characterization of the E → Z photoisomerization (λ = 360 nm) of Azo-Gal(1,3,5)-5 in buffer solution at 25 °C via UV–vis absorption spectroscopy measurements
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Published 15 Jul 2014

Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

  • Christian B. Winiger,
  • Simon M. Langenegger,
  • Oleg Khorev and
  • Robert Häner

Beilstein J. Org. Chem. 2014, 10, 1589–1595, doi:10.3762/bjoc.10.164

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  • thermal denaturation results that accounts for the above mentioned design of building blocks and sequences. UV–vis absorption spectroscopy The stacking interactions of Y and E in the hybrids could be followed by UV–vis absorption spectroscopy. A significant change in the vibronic band ratio supports the
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Published 11 Jul 2014

Multichromophoric sugar for fluorescence photoswitching

  • Stéphane Maisonneuve,
  • Rémi Métivier,
  • Pei Yu,
  • Keitaro Nakatani and
  • Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

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  • function. Actually, fluorescence allows the possibility to reach high sensitivity and very low detection levels, down to the single molecule limit, whereas absorption spectroscopy requires a high number of active molecules [2]. If structural and spectral features of the fluorophore and the photochromic
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Published 30 Jun 2014

Synthesis, characterization and DNA interaction studies of new triptycene derivatives

  • Sourav Chakraborty,
  • Snehasish Mondal,
  • Rina Kumari,
  • Sourav Bhowmick,
  • Prolay Das and
  • Neeladri Das

Beilstein J. Org. Chem. 2014, 10, 1290–1298, doi:10.3762/bjoc.10.130

Graphical Abstract
  • DNA samples were further incubated with 5 units of APE1 enzyme for 1 hour at 37 °C and analyzed by 25% denaturing PAGE run in tris-taurine-EDTA (TTE) buffer at pH 8.0, stained with Sybr-Gold®, gel images acquired and quantified. Fluorescence and absorption spectroscopy The ethidium bromide (EtBr
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Published 05 Jun 2014

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

  • Sarah Bay,
  • Gamall Makhloufi,
  • Christoph Janiak and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

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  • approximation. Keywords: absorption spectroscopy; cyclic voltammetry; chromophores; fluorescence; multicomponent reactions; photo-induced electron transfer; Introduction Chromophores, fluorophores, and electrophores, are functional organic materials [1] and constitute active components in molecular
  • ) compounds. Plotting the extinction coefficient against the wavelength it becomes evident that the Do–anthraquinone dyads behave additively with respect to the constituent reference chromophores (Figure 6). Absorption spectroscopy as a probe for the electronic ground state also supports that in Do
  • the electronic ground state, whereas the emission of the donor moieties is efficiently quenched according to static fluorescence spectroscopy. The observed peculiar fluorescence quenching was previously studied by femtosecond transient absorption spectroscopy of a related model dyad indicating a photo
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Published 05 May 2014

On the mechanism of photocatalytic reactions with eosin Y

  • Michal Majek,
  • Fabiana Filace and
  • Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2014, 10, 981–989, doi:10.3762/bjoc.10.97

Graphical Abstract
  • possible without further spectroscopic, kinetic, and theoretical experiments. The studied systems are mostly too complex for transient absorption spectroscopy. We have so far failed to obtain any insight from photo-CIDNP NMR experiments. Therefore, we have decided to evaluate the efficiency of the
  • heterolytic C–N bond cleavage toward highly reactive aryl cation species. The standard reaction conditions of many literature reports involve concentrations which are orders of magnitude higher than those suitable for absorption spectroscopy studies. This means that even very inefficient transitions (at
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Published 30 Apr 2014
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