Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• turn-off type fluorescent switch (Figure 6c and Figure 7e) [29][30]. The emission from the aggregates quenched much faster than the solution (Figure 6c) (Supporting Information File 2, Movie 1). This is due to a “giant amplification of fluorescence photoswitching” ascribed by a very efficient

Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors

• Christoph W. Grathwol,
• Nathalie Wössner,
• Sören Swyter,
• Adam C. Smith,
• Enrico Tapavicza,
• Robert K. Hofstetter,
• Anja Bodtke,
• Manfred Jung and
• Andreas Link

Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214

• original stilbenoid structure exerted unfavourable photochemical characteristics it was remodelled to its heteroarylic diazeno analogue. By this intramolecular azologization, the shape of the molecule was left unaltered, whereas the photoswitching ability was improved. As anticipated, the highly analogous

• conversion of commercially available methyl 5-aminonicotinate (9) and 4-fluoroaniline to 10 under Mill’s reaction conditions and subsequent ammonolysis of the methyl ester 10 to amide 11 (Scheme 4). Photoswitching of (E)-11 to a long-lived PSS (t½ = 300 h) containing 84% of (Z)-11 was possible by short term

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

• uncontrolled aggregation would result in an additional shift of the TSPR band [15]. In the course of repeated photoswitching experiments, the spectra show a small but significant decrease of the overall nanoparticle absorbance which is most likely due to sedimentation of irreversible aggregates or size

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

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

• , N-alkylcarboxyspiropyrans have been tagged (via ester or amide linkage) to carbon nanotubes (e.g., for photocontrolled Zn2+ delivery in biological media [8]) and gold electrodes (for photoswitching the bioelectrocatalytic cascade of cytochrome c/cytochrome oxidase [9]), and attachment to

The role of alkyl substituents in deazaadenine-based diarylethene photoswitches

• Christopher Sarter,
• Michael Heimes and
• Andres Jäschke

Beilstein J. Org. Chem. 2016, 12, 1103–1110, doi:10.3762/bjoc.12.106

• up new and innovative applications in materials sciences, bionanotechnology, synthetic biology, and biomedical diagnostics, and reversible photoswitching is a particularly attractive goal [1][2][3][4][5][6][7][8][9][10][11][12]. Light is a powerful and convenient trigger for manipulating structure

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

• functionalization was monitored by SPR. Photoswitching of the glycooligomers was realized either ex situ prior to surface functionalization or in situ by direct irradiation of the functionalized chip. The equilibrium constant KD was obtained by fitting the obtained binding values at the turning point between

• the glycooligomers directly on the chip. The KD values showed no difference in binding affinity between E- and Z-isomers when the chip was irradiated directly. This indicates that either the light could not penetrate efficiently through the organic layer of the chip, or more likely that photoswitching

• -(1,3)-3 shows a small difference in lectin binding before and after photoswitching (entry 1, Table 3). This is in contrast to the previous finding of the inhibition/competition assay, where after photoswitching the Azo-Gal(1,3,5)-5 was unaffected while Azo-Gal-(1,3)-3 showed a significant difference in

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

• fluorescence photoswitching by energy transfer process (FRET). Bifunctional fluorescent-photochromic molecules 1 and 2. Absorption and fluorescence spectra of compounds 6, 9, and 2 in CH3CN: (a) absorption spectrum of 6; (b) emission spectrum of 6 (λexc = 450 nm); (c) absorption spectra of 9-OF, 9 at the

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• of the mannobioside is important both to mediate hydrophilicity and to intensify the steric effect that photoswitching has on the exposition of the terminal mannoside. Conclusion The azobenzene mannosides presented herein resemble a structure quite similar to biaryl mannosides, which have been

• favourable physiological properties are considered, such as low toxicity [36] and receptor specificity of the azobenzene aglycon [37]. It will be our next goal to employ derivatives of azobenzene mannobioside 2 for immobilisation to test the photoswitching of adhesion on surfaces. Experimental Materials and

Amino-substituted diazocines as pincer-type photochromic switches

• Hanno Sell,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2013, 9, 1–7, doi:10.3762/bjoc.9.1

• is not formally symmetry forbidden. Even though it has a rather low extinction coefficient (1250 L∙M−1∙cm−1), irradiation into the n–π* band leads to complete conversion back to the trans isomer [14]. Photoswitching of 5,6-dihydrodibenzo[c,g][1,2]diazocine (unsubstituted EBAB 1), however, is

A bisazobenzene crosslinker that isomerizes with visible light

• Subhas Samanta,
• Harris I. Qureshi and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2012, 8, 2184–2190, doi:10.3762/bjoc.8.246

• chromophores completely, while providing N-centered lone pairs to extend the π-system of each independent azo unit. In this manner, independent photoswitching behavior of the two units at wavelengths shifted towards the visible range was expected to occur. Results and Discussion The p-diacetamido piperazine

• , MeOH and sodium phosphate buffer (pH 7.0). (b) UV–vis absorption spectra of 2 (~10 μM) in aqueous buffer at different pHs (indicated). (a) Photoswitching of 2 with violet light (407–410 nm) at different temperatures (4, 10 and 20 °C) in 25 mM sodium phosphate buffer at pH 8. (b) Multiple rounds of

• photoswitching of 2 with alternating violet light (violet bars) and dark adaption (white bars) in 25 mM phosphate buffer, pH 8, at 10 °C. Bisazobenzene derivatives. Synthetic route for the preparation of bisazobenzene derivative 2. Supporting Information Supporting Information File 270: NMR spectra for

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• films. Fluorescence of diarylethenes 1–3 Fluorescence can be used not only in molecular-scale optoelectronics but also in digital photoswitching [22][53][54]. Like most of reported diarylethenes, diarylethenes 1–3 exhibited notable fluorescence in both hexane and PMMA films. Their fluorescence spectra

• for the fluorescence photoswitching material. Electrochemical properties of diarylethenes 1–3 The electrochemical behaviors of diarylethene derivatives have attracted much attention because of their potential applications in molecular-scale electronic switches [57][58][59][60][61][62]. The

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• dark. All melting points are uncorrected. All spectroscopic measurements (including photolysis of DHA to VHF and kinetics studies on the thermal conversion of VHF to DHA) were performed in a cuvette of 1 cm path length. Photoswitching experiments were performed by using a 150 W xenon arc lamp equipped

Diarylethene-modified nucleotides for switching optical properties in DNA

• Sebastian Barrois and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2012, 8, 905–914, doi:10.3762/bjoc.8.103

• [5][6][7][8], azobenzenes [9], spirobenzopyrans [10] and diarylethenes [11] represent the most promising candidates for introducing photoswitching functionality into biopolymers, and thereby for regulating biological activity [12][13]. Azobenzenes were designed and synthesized as artificial

• buffer solutions [31], and (according to our experience) the DNA environment does not efficiently prevent this decomposition. (ii) Moreover, we found out that the spiropyran chromophore in the DNA environment loses its photoswitching abilities [29]. The second alternative, diarylethenes, have been

• % yield. Photochromic properties of diarylethene-modified 2’-deoxyuridines 4–6 The photochromic properties of the modified nucleosides 4–6 were characterized by UV–vis absorption spectroscopy at rt. All irradiations for photoswitching of the nucleosides were performed by using a 75 W Xe arc lamp equipped