Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

• Mingbing Zhong,
• Xavier Pannecoucke,
• Philippe Jubault and
• Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

• and co-worker described the synthesis of a new heteroleptic copper complex bearing a substituted bipyridine ligand (Scheme 18) [34]. The novel copper catalyst was fully characterized by X-ray crystallographic analysis, UV–visible absorption and emission as well as cyclic voltammetry. The catalyst [Cu

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• single−quadrupole mass spectrometer. UV–visible (UV–vis) spectra were recorded on a Hitachi U-2001 dual beam spectrophotometer. Fluorescence emission spectra were recorded in solution on a Hitachi F-7000 fluorescence spectrophotometer. Viscosity experiments were carried out using an ALPHA L Fungilab

A photochemical determination of luminescence efficiency of upconverting nanoparticles

• Baptiste Amouroux,
• Clément Roux,
• Jean-Claude Micheau,
• Fabienne Gauffre and
• Christophe Coudret

Beilstein J. Org. Chem. 2019, 15, 2671–2677, doi:10.3762/bjoc.15.260

• about the fraction of light effectively absorbed by the medium and also the possibility of particle sedimentation. All this set-up was placed inside a UV–visible spectrophotometer (Figure 2). Using cyclohexane as a common solvent for both diarylethene 1 and UCNPs, we have chosen to work on mixtures of

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• ). Finally, the photophysical properties of ligand syn-1 (20 μM) and complexes 1a–d (30 μM) were evaluated in dichloromethane (Supporting Information File 1, Figures S4–S8). The UV–visible and fluorescence emission spectra (λexc = 345 nm) of ligand and complexes were similar and correspond to those of 9,10

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• synthesized the novel tetra-1,2,3-triazolium zinc porphyrin cage 3 (Figure 4) and have probed its characteristics by using UV–visible spectroscopy, determining the association constants for complex formation in 5% water/acetone. This receptor has shown affinity toward all of the halide ions and especially

A golden opportunity: benzofuranone modifications of aurones and their influence on optical properties, toxicity, and potential as dyes

• Joza Schmitt and
• Scott T. Handy

Beilstein J. Org. Chem. 2019, 15, 1781–1785, doi:10.3762/bjoc.15.171

• sake of high purity, so yields should not be considered optimized. Spectral and toxicity studies With the desired compounds in hand, their UV–visible spectra were recorded at concentrations between 29 and 44 μM in acetonitrile (Figure 3 and Table 1). While not all substituents were prepared at every

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• gap between HOMO and LUMO than the energy gap between the HOMO of the acceptor and the LUMO of the donor when the two compounds are separated. This transition is generally observed with high intensity on the UV–visible spectra [20]. 1.3.4 Ligand to metal charge transfer (LMCT): The LMCT transition is

• -phenylpyridine)iridium) has been chosen and is depicted in Scheme 2. This metal complex is also commercially available. Ir(ppy)3 exhibits a MLCT transition in the near UV–visible range. The photochemical properties of this complex are gathered in Table 3. Interestingly, it is also possible to tune both the light

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• Union Road, Cambridge, CB2 1EZ, UK (fax: +44-(0)1223-336033 or e-mail: despoit@ccdc.cam.ac.uk). Supporting Information File 474: Experimental procedures, copies 1H and 13C NMR spectra for all reported compounds, details of XRD analysis and UV–visible spectra for kinetic assays. Acknowledgements This

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• preferred 3:1 for [1FDB24C8]2+ and 9:1 for [1ADB24C8]2+ in CD3CN and when CD2Cl2 was used the systems were completely bistable with DB24C8 preferring to reside exclusively at the bis(pyridinium)ethane site when unprotonated and exclusively at the benzylanilinium site when protonated. The UV–visible spectra

• crown resides solely on the bis(pyridinium)ethane site for [8DB24C8]6+ but, when the [2]catenane does not absorb in the UV–visible region yielding a colorless solution this means the crown ether must be shuttling (i.e., circumrotating) back and forth between the two co-conformations, A and B, of [8

• , e.g., s’ versus s. UV–visible spectra of [8DB24C8]6+ (orange trace) and [8-HDB24C8]7+ (black trace) in CH3CN solution at 2.0 × 10−5 M and 298 K. Step-wise synthesis of [2]catenane [8DB24C8]6+ containing benzylanilinium and bis(pyridinium)ethane recognition sites and terphenyl spacers. Summary of major

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• change in particle morphology is in qualitative agreement with that in the specific surface area (see Table 1). Figure 4 shows the UV–visible diffuse reflectance spectra of g-C3N4 synthesized at different temperatures. All of the samples exhibited an absorption edge at 420–450 nm, attributed to electron

• Kα radiation), Fourier-transform infrared (FTIR) spectroscopy (FTIR-610, Jasco), transmission electron microscopy (TEM) (JEM-2010F, JEOL), and UV–visible diffuse reflectance spectroscopy (DRS) (V-565, Jasco). The Brunauer–Emmett–Teller (BET) surface area of each specimen was determined using a

• measurement. FTIR spectra of g-C3N4 synthesized at different temperatures. Each spectrum was acquired by a KBr method in N2 atmosphere. TEM images of g-C3N4 synthesized at different temperatures. UV–visible diffuse reflectance spectra of g-C3N4 synthesized at different temperatures. A typical TEM image of Ag

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• on T13 and T14 showed the two molecules to exhibit a similar electronic distribution, what was confirmed by UV–visible and photoluminescence (PL) spectroscopy. Only a slight red shift of the absorption was detected for T14 as the result of the strengthened donating ability of the dicarbazolylphenyl

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

• Henning Weiss,
• Jeannine Reichel,
• Helmar Görls,
• Kilian Rolf Anton Schneider,
• Mathias Micheel,
• Michael Pröhl,
• Michael Gottschaldt,
• Benjamin Dietzek and
• Wolfgang Weigand

Beilstein J. Org. Chem. 2017, 13, 2264–2272, doi:10.3762/bjoc.13.223

• . Recrystallization from acetone or ethanol and water mixtures gave the pure products 3a–c and 3e–h as yellow or orange solids in good to excellent yields. They were characterized by 1H and 13C{1H} NMR spectroscopy, mass spectrometry, UV-visible spectroscopy and elemental analysis. For 3d we found two sets of NMR

Structural diversity in the host–guest complexes of the antifolate pemetrexed with native cyclodextrins: gas phase, solution and solid state studies

• Magdalena Ceborska,
• Magdalena Zimnicka,
• Aneta Aniela Kowalska,
• Kajetan Dąbrowa and
• Barbara Repeć

Beilstein J. Org. Chem. 2017, 13, 2252–2263, doi:10.3762/bjoc.13.222

• reported in ppm relative to DMSO (δ = 2.5 ppm) and HDO (δ = 4.8 ppm). Chemical shifts for PTX [30] and CDs in D2O [31], and DMSO [32] are consistent with the literature data. Ultraviolet-visible spectroscopy (UV–vis) The UV–visible absorption spectra of PTX-Na2, and its respective associates with α-CD, β

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

• Alexis Perry and
• Christina J. Kousseff

Beilstein J. Org. Chem. 2017, 13, 1542–1550, doi:10.3762/bjoc.13.154

• . In this study, we describe an efficient synthesis of spiropyrans with 2–12 carbon atom alkylcarboxylate substituents, and a systematic analysis of their interactions with metal cations using 1H NMR and UV-visible spectroscopy. All N-alkylcarboxyspiropyrans in this study displayed a strong preference

• lactonisation is avoided through the use of ethyl 4-bromobutyrate, and basic ester hydrolysis is required as a final step (Table 1, entry 5). Binding studies Analysis of spiropyran–merocyanine equilibria with respect to metal binding has frequently employed UV-visible spectroscopy. Merocyanine–metal cation

• spiropyran isomer are labelled; aromatic peaks from the merocyanine–Zn2+ complex are broad and unassigned. SP:MC was estimated by comparison of integral values from SP 3′-H and MC (N+CH2)/2 (as shown in red). (b) UV-visible absorbance spectrum of C10SP (0.1 mM) and Zn(NO3)2·6H2O (0.02 mM) in CD3CN/CH3CN–H2O

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• of UV–visible single-crystal spectroscopy. Providing extreme care is taken to avoid artefacts, these methods are in principle available to a wide range of biological systems. Two types of intermediate trapping schemes are available. In the so-called “trigger-freeze” experiment, a large fraction of

The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil

• Joyce Azzi,
• Pierre-Edouard Danjou,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2017, 13, 835–844, doi:10.3762/bjoc.13.84

• , CRYSMEB and SBE-β-CD) were determined by phase solubility studies and confirmed by the spectral displacement UV-visible method. The solubility of cabreuva essential oil (EO) rich in trans-Ner was also evaluated by total organic carbon (TOC) analysis. The encapsulation efficiency (EE %) of Ner in HP-β-CD

• Ner with seven CDs: α-CD, β-CD, γ-CD, HP-β-CD, RAMEB, CRYSMEB and SBE-β-CD using phase solubility studies coupled to HPLC. The Kf values were determined for the separate isomers and their commercial mixture. To confirm the Kf values obtained for the isomeric mixture, UV-visible spectroscopy was

• compounds has been reported in the literature [20][21][22]. However, HP-β-CD is the only β-CD derivative cited in the FDA’s list of Inactive Pharmaceutical Ingredients among the studied derivatives, therefore, further studies will focus on this CD. UV–visible spectroscopy Formation constants between Ner

Biochemical and structural characterisation of the second oxidative crosslinking step during the biosynthesis of the glycopeptide antibiotic A47934

• Veronika Ulrich,
• Clara Brieke and
• Max J. Cryle

Beilstein J. Org. Chem. 2016, 12, 2849–2864, doi:10.3762/bjoc.12.284

• of StaF Spectral analysis of P450s allows determination of their potential catalytic competence. The UV–visible spectrum of StaF exhibited a Soret maximum at λ = 421 nm and β/α bands at λ = 539 and 566 nm, respectively (Figure 2a). This corresponds to the absorption spectra characteristic for P450s

• of sodium dithionite led to conversion of ferric to ferrous heme, which was accompanied by shift of the Soret maximum to λ = 422 nm and of the β/α bands to λ = 532 and 559 nm in the UV–visible spectrum. Upon saturation of ferrous StaF with carbon monoxide, two major peaks appeared at λ = 420 and 450

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

• (KCTP) conditions. We compare the behavior of the block copolymer to that of the corresponding homopolymer blends. In both types of system, we find the fluorinated segments tend to dominate the UV–visible absorption and molecular vibrational spectral features, as well as the thermal behavior. In the

• polymers’ UV–visible absorption and Raman scattering spectra are compared with those of the corresponding blends of P3OT and F-P3OT, as well as the homopolymers. The results of this study suggest that the tethering of P3OT and F-P3OT blocks may not lead to spontaneous large-scale phase separation behavior

• that of P3OT (4.70 eV) measured by the same technique [42], while the 1:4 copolymer had an IP of 5.03 eV, which is within experimental error (±0.05 eV) of the IP of F-P3OT (4.99 eV) [42]. To investigate the influence of the block compositions on the optical properties, the UV–visible absorption spectra

Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

• Peng Zhang,
• Xiao-Ming Li,
• Xin-Xin Mao,
• Attila Mándi,
• Tibor Kurtán and
• Bin-Gui Wang

Beilstein J. Org. Chem. 2016, 12, 2012–2018, doi:10.3762/bjoc.12.188

• spectra were recorded on a VG Autospec 3000 spectrometer. HPLC analyses were carried out on a Dionex HPLC system (P680 HPLC pump, UVD 340U UV–visible detector) using a C18 column (5 μm, 8.0 mm i.d. × 250 mm). Commercial silica gel (100−200 mesh and 200−300 mesh) for column chromatography were purchased

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• terthiophene matrix and run on a Bruker Autoflex III MALDI–TOF–TOF–MS. UV–visible absorption and emission spectra were collected in HPLC grade chloroform on a UV-Cary 50 spectrometer and a Cary Eclipse fluorescence spectrometer, respectively. Solutions for films were prepared at 10 mg/mL concentration in HPLC

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

• CARY100 UV–visible spectrophotometer using the Cary WinUV Scan software 3.00(182). Fluorescence emission spectroscopy was conducted using a Perkin Elmer LS 55 fluorescence spectrometer. All in situ FTIR spectroscopy experiments (ReactIR, Mettler Toledo) were carried out using a ReactIR 15 with MCT

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• , based on the known colorful azulene-derivatives, we undertook preliminary experiments involving terpyridine 4a for possible selective detection of poisoning metal ions. As representative examples, we have chosen Hg(II) and Cd(II) metal ions. UV–visible titration was performed by adding increasing

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• collect it from the extraction thimble at the polymer purification stage while PTzBDT-2, was extracted with chloroform thanks to its better solubility. Optical and electrochemical properties The UV–visible absorption spectra of the pristine PTzBDT-1 and PTzBDT-2 polymers in dilute solution (in

• force microscopy (AFM) images, recorded directly on tested devices, were taken with a Solver Pro (NT-934 MDT) scanning probe microscope in tapping mode. UV–visible absorption spectra of the pristine PTzBDT-1 and PTzBDT-2 (A) in chlorobenzene and chloroform, respectively and thin film processed from

Application of Cu(I)-catalyzed azide–alkyne cycloaddition for the design and synthesis of sequence specific probes targeting double-stranded DNA

• Svetlana V. Vasilyeva,
• Vyacheslav V. Filichev and
• Alexandre S. Boutorine

Beilstein J. Org. Chem. 2016, 12, 1348–1360, doi:10.3762/bjoc.12.128

• of the probe fluorescence has been observed in our previous work [2][3]. Thus, only F1-NH2-MM14 is sequence-specific. We ascribe this low specificity of F1-NH2-TO to strong intercalation properties of the TO fluorophore that can intercalate into DNA independently of the polyamide. UV-visible