Reversible photoswitching of the DNA-binding properties of styrylquinolizinium derivatives through photochromic [2 + 2] cycloaddition and cycloreversion

• Sarah Kölsch,
• Heiko Ihmels,
• Jochen Mattay,
• Norbert Sewald and
• Brian O. Patrick

Beilstein J. Org. Chem. 2020, 16, 111–124, doi:10.3762/bjoc.16.13

• the alkene protons (3JH–H = 16 Hz) [70]. Absorption and emission properties The photophysical properties of the styrylquinolizinium derivatives 3a and 3c have already been reported [69], while the ones of 3b and 3d were determined in this work (Table 1 and Figure 1). In acetonitrile, the derivatives

Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes

• Andreas H. Heindl and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2020, 16, 22–31, doi:10.3762/bjoc.16.4

• 20% was achieved, whereas the methoxy derivative 3b could be isolated in a good yield of 59%. Having both tris(arylazo)benzenes 3a/3b in hand, UV–vis spectroscopy was used for preliminary investigations on the photophysical properties of the molecular triple switches 3. Both tris(arylazo)benzenes 3a

Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

• Daniel R. Sutherland,
• Nidhi Sharma,
• Georgina M. Rosair,
• Ifor D. W. Samuel,
• Ai-Lan Lee and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285

• LUMO energies of 2–5 are in good agreement with the calculated values (Figure 3). Photophysical properties We next investigated the photophysical properties of 2–5. The UV–vis absorption and photoluminescence (PL) spectra in degassed DCM solution are shown in Figure 5, and the data are summarized in

• theoretical, electrochemical, and photophysical properties of the donor–acceptor compounds 2–5 were determined in solution and thin film. While compounds 2, 4, and 5 were very poorly emissive, 3 showed a green emission with a biexponential lifetime characterized by a prompt nanosecond component and a delayed

Design, synthesis and investigation of water-soluble hemi-indigo photoswitches for bioapplications

• Daria V. Berdnikova

Beilstein J. Org. Chem. 2019, 15, 2822–2829, doi:10.3762/bjoc.15.275

• . Photochemical and photophysical properties of hemi-indigo derivatives 1a–c and 2 in water. Supporting Information Supporting Information File 610: Additional spectral data, detailed description of the experiments performed, NMR of compounds Z-1a–c and LED characteristics. Acknowledgements This project has

Chemical tuning of photoswitchable azobenzenes: a photopharmacological case study using nicotinic transmission

• Lorenzo Sansalone,
• Jun Zhao,
• Matthew T. Richers and
• Graham C. R. Ellis-Davies

Beilstein J. Org. Chem. 2019, 15, 2812–2821, doi:10.3762/bjoc.15.274

• preserving all the favorable photophysical properties of the parent 4FAB scaffold, however, the tetrafluoro motif can significantly perturb pharmacophore–protein interactions. In contrast, we found that the freely diffusible 4FABTA probe could be pre-set with green light into an OFF state that was

Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

• Valentina A. Ol’shevskaya,
• Elena G. Kononova and
• Andrei V. Zaitsev

Beilstein J. Org. Chem. 2019, 15, 2704–2709, doi:10.3762/bjoc.15.263

• the maleimide group with its rich biological activity to the tetrapyrrole macrocycles with their unique photophysical properties may result in new conjugates with improved chemical, biological and anticancer characteristics [28]. Moreover, maleimide is a stable functionality that rapidly and

Emission solvatochromic, solid-state and aggregation-induced emissive α-pyrones and emission-tuneable 1H-pyridines by Michael addition–cyclocondensation sequences

• Natascha Breuer,
• Irina Gruber,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2019, 15, 2684–2703, doi:10.3762/bjoc.15.262

• , dimethylamino-substituted α-pyrones, as donor–acceptor systems, display remarkable photophysical properties, such as strongly red-shifted absorption and emission maxima with daylight fluorescence and fluorescence quantum yields up to 99% in solution and around 11% in the solid state, as well as pronounced

• achieved [4]. Small molecule organic fluorophores are particularly advantageous due to the potential of a tailored fine-tuning of their photophysical properties through synthetic modifications [5]. Based on their structural features, functionalized organic chromophores, containing N-, O- or S-atoms, are

• Supporting Information File 1) [50][51][52][53][54][55][56][57]. Photophysical properties Photophysical properties of 1H-pyridines 5 and 8 1H-Pyridine derivatives 5 are yellow or orange compounds under daylight (Figure 3, top) and fluoresce in solution (Figure 3, center) and in the solid state (Figure 3

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• -soluble and selective bioprobe for plasma membrane imaging. The new compound was efficiently synthesized in a two-step procedure with good yields. The photophysical properties were evaluated and the dye proved to have an excellent photostability in several solvents. DFT calculations were found in

• derivative. The photophysical properties of the new compound BTDE-4APTEG have been investigated and the results are summarized in Table 1 and presented in Figure 2. All absorption maxima were observed in the UV region close to 375 nm and with reasonable molar extinction coefficients. Large Stokes shifts were

• yielded the best overall performance across all studied solvents with an absolute deviation below 10 nm. PBE1PBE was therefore selected as the most suitable XCF (amongst the six investigated XCFs) for studying the photophysical properties of BTD-4APTEG. The structure geometry was fully optimized in

Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence

• Vânia F. Pais,
• Tristan Neumann,
• Ignacio Vayá,
• M. Consuelo Jiménez,
• Abel Ros and
• Uwe Pischel

Beilstein J. Org. Chem. 2019, 15, 2612–2622, doi:10.3762/bjoc.15.254

• advantageous photophysical properties that include spectrally tunable and highly intense fluorescence [1][2]. On the one hand, those compounds that contain the boron atom in a valence-saturated situation corresponding to sp3 hybridization (such as Bodipy dyes [3][4], N,C-chelate organoboron dyes [5][6][7][8][9

• electron-transfer phenomena or two-photon absorption [32][33][34][35][36]. As part of our research program we have developed arylisoquinolines that integrate a boronic acid ester [37][38][39] or a BMes2 unit [6][40]. The presence of the boron-substituent confers interesting photophysical properties to

• the verification of the effect of aromatic conjugation (naphthyl, anthryl, pyrenyl) and electron-donor strength (naphthyl versus 4-methoxynaphthyl) on the photophysical properties. Beside the observation of interesting dual emission properties for these dyes, some showed a pronounced ratiometric

Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red

• Aydan Yadigarli,
• Qimeng Song,
• Sergey I. Druzhinin and
• Holger Schönherr

Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248

• substrate-supported ultrathin films [13], the analysis of the photophysical properties of tracer dye molecules was found to be beneficial. In time-resolved fluorescence measurements and dye diffusion studies, the nanoenvironments in polymersomes could be assigned [1][12], solute transport be characterized

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

Mono- and bithiophene-substituted diarylethene photoswitches with emissive open or closed forms

• A. Lennart Schleper,
• Mariano L. Bossi,
• Vladimir N. Belov and
• Stefan W. Hell

Beilstein J. Org. Chem. 2019, 15, 2344–2354, doi:10.3762/bjoc.15.227

• ) were detected, confirming cleavage of the methyl esters. Photophysical properties The absorption and emission properties as well as the photochromic properties of eight “thiophenylated” DAEs were studied in acetonitrile solutions (Table 1). The properties of the OFs (open forms) were obtained from

Synthesis of a dihalogenated pyridinyl silicon rhodamine for mitochondrial imaging by a halogen dance rearrangement

• Jessica Matthias,
• Thines Kanagasundaram,
• Klaus Kopka and
• Carsten S. Kramer

Beilstein J. Org. Chem. 2019, 15, 2333–2343, doi:10.3762/bjoc.15.226

• photophysical properties of numerous silicon rhodamines leading to further insights into the correlation of the dyes’ chemical structure with their fluorogenic behavior [27]. Regarding the quantum yield, Hanaoka et al. have shown that introduction of methyl, methoxy or dimethylamine groups into the benzene

• experiments (supported by DFT calculations) on the orbital effects of both halogens and the nitrogen position in the pyridine ring are needed to explain these effects with confidence. In addition, our SiR dye 15 displays photophysical properties (extinction coefficient, quantum yield, lifetime) in the same

Fluorescent phosphorus dendrimers excited by two photons: synthesis, two-photon absorption properties and biological uses

• Anne-Marie Caminade,
• Artem Zibarov,
• Eduardo Cueto Diaz,
• Aurélien Hameau,
• Maxime Klausen,
• Kathleen Moineau-Chane Ching,
• Jean-Pierre Majoral,
• Jean-Baptiste Verlhac,
• Olivier Mongin and
• Mireille Blanchard-Desce

Beilstein J. Org. Chem. 2019, 15, 2287–2303, doi:10.3762/bjoc.15.221

• dendrimers having TPA fluorophores as branches and water-solubilizing functions on the surface. Photophysical properties of the types of dendrimers shown in Scheme 2 (measured in toluene). Comparison of the photophysical properties (in toluene) of the spherical dendrimers shown in Scheme 2, with that of the

Synthesis and properties of sulfur-functionalized triarylmethylium, acridinium and triangulenium dyes

• Marco Santella,
• Eduardo Della Pia,
• Jakob Kryger Sørensen and
• Bo W. Laursen

Beilstein J. Org. Chem. 2019, 15, 2133–2141, doi:10.3762/bjoc.15.210

• fluorescence lifetime (τfl) [12][13] are key photophysical properties to consider and optimize for any given application. We have for quite some time been interested in the synthesis, properties and applications of dyes from the triangulenium family (Figure 1) [14][15]. The triangulenium dyes can be divided

• also in agreement with the observation that 5a (and 5b) display intense fluorescence (Figure 6). Table 3 summarizes the spectral and photophysical properties on the triangulenium dyes showing any applicable fluorescence. Beside S3-ADOTA+ (5a) that are the double and triple -SEt-substituted TOTAs 6 and

Synthesis of benzo[d]imidazo[2,1-b]benzoselenoazoles: Cs₂CO₃-mediated cyclization of 1-(2-bromoaryl)benzimidazoles with selenium

• Mio Matsumura,
• Yuki Kitamura,
• Arisa Yamauchi,
• Yoshitaka Kanazawa,
• Yuki Murata,
• Tadashi Hyodo,
• Kentaro Yamaguchi and
• Shuji Yasuike

Beilstein J. Org. Chem. 2019, 15, 2029–2035, doi:10.3762/bjoc.15.199

• -fluorobenzene, and Se powder under the optimized conditions, i.e., in the presence of Cs2CO3 (2 equiv) in DMF under an argon atmosphere at 150 °C. This reaction gave product 2a in only 35% yield, suggesting that the stepwise reaction via 1-(2-bromoaryl)benzimidazole 1 is superior. Next, the photophysical

• properties of the synthesized compounds were evaluated, and the corresponding data are shown in Table 2 and Figure 3. 1-Phenylbenzimidazole (11), which does not contain a selenium atom, has an absorption maximum at 283 nm. In contrast, the maximum absorption wavelength (λmax) of parent compound 2a was found

Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• azobenzenes with different halogen bonding donor properties are discussed in relation to their changing photophysical properties, rationalized by DFT calculations. Keywords: azobenzene; DFT calculations; fluorine chemistry; halogen bonding; photochemistry; Introduction The halogen bond is an attractive

• iodoethynyl group, as trade-off, photophysical properties are changing. The bathochromic shift of the π→π* band leads to an overlap with the n→π* excitation, making it more difficult to address, together with a diminishing thermal half-life. Both effects can be qualitatively reproduced and understood with the

Identification of optimal fluorescent probes for G-quadruplex nucleic acids through systematic exploration of mono- and distyryl dye libraries

• Xiao Xie,
• Michela Zuffo,
• Marie-Paule Teulade-Fichou and
• Anton Granzhan

Beilstein J. Org. Chem. 2019, 15, 1872–1889, doi:10.3762/bjoc.15.183

• at the improvement of photophysical properties of the dyes and the establishment of structure–properties relationships. Results Design and synthesis of the dye library On the basis of the previously established distyryl scaffold, we designed 49 novel derivatives through systematic variation of the

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

• platform 2 (44%). The photophysical properties and the switching behaviour of 1, 2 and 3 were determined in solution (THF). The UV–vis spectra of the norbornadienes (NBD, black, 1a, 2a, 3a) and quadricylanes (QC, red, 1b, 2b, 3b) and the spectra of the QCs after irradiation with 311 nm for 1b and 2b or 254

Synthesis, photophysical and electrochemical properties of pyridine, pyrazine and triazine-based (D–π–)₂A fluorescent dyes

• Keiichi Imato,
• Toshiaki Enoki,
• Koji Uenaka and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2019, 15, 1712–1721, doi:10.3762/bjoc.15.167

• solvents are much larger than those in nonpolar solvents (Table 1). In order to investigate the solid-state photophysical properties of OUY-2, OUK-2 and OUJ-2, we have measured the solid-state fluorescence spectra of the solids (Figure 4). The λmax,fl of the as-recrystallized dyes appears at 550 nm for OUY

Synthesis, enantioseparation and photophysical properties of planar-chiral pillar[5]arene derivatives bearing fluorophore fragments

• Guojuan Li,
• Chunying Fan,
• Guo Cheng,
• Wanhua Wu and
• Cheng Yang

Beilstein J. Org. Chem. 2019, 15, 1601–1611, doi:10.3762/bjoc.15.164

• derivatives (P5A-DPA and P5A-Py) bearing bulky fluorophores were obtained in high yield by click reaction. The photophysical properties of both compounds were investigated in detail. P5A-DPA with two 9,10-diphenylanthracene (DPA) pigments grafted on the pillar[5]arene showed a high fluorescence quantum yield

• quantum yield are beneficial for the application of pillar[5]arene in these fields. Perylene (Py) and 9,10-diphenylanthracene (DPA) are well known for their desirable absorption and high fluorescence quantum yield. These chromophores possess unique photophysical properties and have been widely used as

• be inhibited generating a pair of Sp and Rp enantiomers. Secondly, the strong absorption in the visible range and high fluorescence a quantum yield of the fluorophores will donate the pillar[5]arene derivatives novel photophysical properties. Results and Discussion Syntheses of pillar[5]arene

Diazocine-functionalized TATA platforms

• Roland Löw,
• Talina Rusch,
• Fynn Röhricht,
• Olaf Magnussen and
• Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1485–1490, doi:10.3762/bjoc.15.150

• for dibenzoyl 7 (Scheme 1). Diazocine 13 was obtained by reduction and oxidation in moderate yields (22%). The reaction of diazocine 13 with the TATA ion 9 gave the target diazocine 2 (88%, Scheme 2). The photophysical properties and the switching behavior of 1 and 2 were determined in solution (THF

Reversible end-to-end assembly of selectively functionalized gold nanorods by light-responsive arylazopyrazole–cyclodextrin interaction

• Maximilian Niehues,
• Patricia Tegeder and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2019, 15, 1407–1415, doi:10.3762/bjoc.15.140

• photophysical properties like nearly quantitative isomerization, straight forward synthesis in excellent yields and very long Z-isomer half-life times up to 1000 days due to less steric repulsion [37]. In previous reports we could show that the AAP guest inclusion properties to β-CD are comparable to

• azobenzenes leading due to the superior photophysical properties to fully reversible supramolecular systems, which showed limited feasibility with azobenzenes [20][38][39]. Herein, we present the application of a light-responsive CD–AAP host–guest system for the reversible end-to-end assembly of AuNR. The

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• and potential applications according to the diverse photophysical responses are provided. Keywords: calixarene; host–guest complexation; luminescent dyes; macrocycles; photophysical properties; Introduction Fluorescence sensing represents a powerful detection methodology due to its low cost, ease of

• GC5A–dye complexes. Binding constants and photophysical properties of host–guest complexes and the calculated polarities of macrocyclic hosts. Acknowledgements This work was supported by NSFC (21672112 and 51873090), the Fundamental Research Funds for the Central Universities and Program of Tianjin

Remarkable effect of alkynyl substituents on the fluorescence properties of a BN-phenanthrene

• Alberto Abengózar,
• David Sucunza,
• Patricia García-García and
• Juan J. Vaquero

Beilstein J. Org. Chem. 2019, 15, 1257–1261, doi:10.3762/bjoc.15.122

• -phenanthrenes with substituents of a diverse nature have been synthesized by palladium-catalyzed cross-coupling reactions of a common chloro-substituted precursor, which was made from readily available materials in only four steps. Evaluation of the photophysical properties of the prepared compounds unveiled an

• aromatic hydrocarbons (BN-PAHs) have received increasing interest over the past few years [1][2][3][4][5], particularly in the field of materials science [6]. The presence of a polarized B–N bond induces significant changes in the photophysical properties of these compounds when compared to their PAH

• analogues containing only non-polar C=C bonds. This fact opens up new opportunities for creating improved optoelectronic devices [7][8][9][10][11][12][13][14][15]. The introduction of substituents is known to have a substantial influence on the photophysical properties of PAHs. However, although some