Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• was then taken at time intervals of 15–30 minutes for a total of 3 h. The UV–vis monitoring revealed that the absorbance decreases as irradiation continues, indicating photodegradation; however, no evidence of a [2 + 2] cycloaddition product was seen in the spectra (Supporting Information File 1

• light irradiation, undergoing rearrangement and photodegradation, so there may be a risk of degradation if irradiation using UV light is tried. Alternatively, the lack of a [2 + 2] cycloaddition of Me2B, may be due to its photophysical properties not allowing for a reaction to occur, rather than the

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• through specific chemical modifications, further enhancing their versatility for a range of synthetic and photophysical applications as well as preventing their photodegradation (Figure 10) [57][58][59][60]. The use of cyanins as near-infrared photosensitizers was first introduced in photopolymerization

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• the corresponding abilities to prevent photodegradation are substantially improved by a substituent in the 5-position rather than by the presence of a substituent in the 4-position. Moreover, either oxybenzone, which contains a methoxy group in the 5-position and is the most commonly used commercial

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• (Figure 2b). Interestingly, the viscosity of the gels was progressively reduced due to the decrease of the physical entanglement of the polymeric chains via photodegradation. Thus, the viscoelasticity of the rotaxane-based gels could be fine-tuned by modifying the irradiation time. This visible-light

• photodegradation of intertwined gels could lead to advanced functional materials avoiding the UV phototoxicity for biocompatible implementations, such as protein patterning and tissue engineering. Light-responsive metal-organic rotaxane frameworks The integration of the mechanical bond into metal-organic

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• known to modify and/or improve the physical and chemical properties of the included guest, ensuring the protection of labile molecules from photodegradation or oxidation [3][6][23]. Moreover, many CD derivatives are available, opening the possibility of using different chemical functions (ester, imine

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• packed bed. Together with the catalyst deactivation observed in the temperature study, this result points at a temperature-dependent ligand photodegradation as a likely deactivation mechanism. The amount of nickel leaching observed is significant and, depending on the substrate, the metal contamination

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• on the adsorption and/or photodegradation of dyes. In general, these performances are reported on bulk g-CN materials, such as the on a self-standing ultra-long porous g-CN wires exhibiting outstanding RhB adsorption values by minimized solvent uptakes [46]. In our case, we focus on the RhB releasing

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• center for dye degradation. Interestingly, the photodegradation rate was significantly improved (≈95%) by adding ethylenediaminetetraacetic acid (EDTA, 0.02 mM) as the hole scavenger. To evaluate the stability of the TiO2–AuNCs@β-CD catalyst, recycling experiments were conducted. These results implied

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• microcapillaries range from 10 µm to 1 mm. The microcapillary films are transparent to UV and visible light. Furthermore, they have a refractive index close to water (≈1.33), which makes them good candidates for photochemical reactors. In one study, those microcapillary films were used for the photodegradation of

• indigo carmine, diclofenac, and benzoylecgonine. The reactor volume was 0.15 mL [36]. The PSTY of the photodegradation of indigo carmine was calculated as 0.01 mol·day−1·kW−1 (Table 1, entry 8). In another study, those microcapillary films were used to synthesize ascaridole, an antimalarial drug, from α

Synthesis and highly efficient light-induced rearrangements of diphenylmethylene(2-benzo[b]thienyl)fulgides and fulgimides

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Valerii V. Tkachev,
• Andrey N. Utenyshev,
• Olga Yu. Karlutova,
• Alexander D. Dubonosov,
• Vladimir A. Bren,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2020, 16, 1820–1829, doi:10.3762/bjoc.16.149

• persistance to photodegradation. It has been shown that annulation of benzene rings to the five-membered rings of pyrryl, thienyl and furanyl fulgides can promote the additional improvement of these properties [10][18][19][20][21]. In accordance with these data, we have previously synthesized and studied the

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• components in the coating, leaving the TiO2 powder exposed [75]. In 1938, Goodeve and Kitchener used this knowledge to perform the first study on the photodegradation of organic dyes with TiO2 powder [76]. A series of subsequent reports that were historically relevant to developing TiO2- and semiconductor

Cation-induced ring-opening and oxidation reaction of photoreluctant spirooxazine–quinolizinium conjugates

• Phil M. Pithan,
• Sören Steup and
• Heiko Ihmels

Beilstein J. Org. Chem. 2020, 16, 904–916, doi:10.3762/bjoc.16.82

• merocyanine formation, and the irradiation with light mainly led to photodegradation of the substrates. However, it was shown by colorimetric and fluorimetric screening assays as well as by detailed NMR spectroscopic and mass spectrometric studies that the addition of particular metal ions (Cu2+, Fe3+, and to

• photodegradation of the substrate (Figure S2A, Supporting Information File 1). For 3b, the irradiation at 420 nm led to a decrease of the absorption and a bathochromic shift of the long-wavelength absorption band, and after an irradiation time of 60 min, the spectrum showed distinct absorption bands with maxima at

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

• factor of 1.43 [11]. Theoretical calculations Calculations for the photodegradation of carbamates The structures, properties and the basic photochemistry of compounds 11 and 12 was studied using the density functional theory (DFT) method [86][87][88][89] and the functional B3PW91 along with the 6-31 G(d

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

• Lei Zhang,
• Greta Linden and
• Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

• trans → cis at these conditions, Figure S24C, Supporting Information File 1) without any signs of photodegradation and photochemical fatigue up to 20 cycles under visible-light irradiation. Regarding the photoconversion ratios between isomers (Table 1), PNA12(oF4Azo) (3) had the best ratios. However

Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

• Alessandro Iagatti,
• Baihao Shao,
• Alberto Credi,
• Barbara Ventura,
• Ivan Aprahamian and
• Mariangela Di Donato

Beilstein J. Org. Chem. 2019, 15, 2438–2446, doi:10.3762/bjoc.15.236

• photodegradation and limit the photoisomerization processes, the pump energy on the sample was reduced to 0.8 μJ/pulse at 400 nm and 4 μJ/pulse at 350 nm. Emission from the sample, collected at right angle with a 1 mm slit, was focused by means of a system of lenses into the spectrograph slit. Streak images were

• field monochromator coupled to a home-made CCD detector. TAS measurements were carried out in a quartz cell (2 mm thick) mounted on a movable stage to avoid sample photodegradation and multiple photon excitation. The recorded kinetic traces and transient spectra have been analyzed by using a global

Excited state dynamics for visible-light sensitization of a photochromic benzil-subsituted phenoxyl-imidazolyl radical complex

• Yoichi Kobayashi,
• Yukie Mamiya,
• Katsuya Mutoh,
• Hikaru Sotome,
• Masafumi Koga,
• Hiroshi Miyasaka and
• Jiro Abe

Beilstein J. Org. Chem. 2019, 15, 2369–2379, doi:10.3762/bjoc.15.229

• Abstract Visible-light sensitized photoswitches have been paid particular attention in the fields of life sciences and materials science because long-wavelength light reduces photodegradation, transmits deep inside of matters, and achieves the selective excitation in condensed systems. Among various

• been paid particular attention in the fields of life sciences and materials science because long-wavelength light reduces photodegradation, transmits deep inside of matters, and achieves the selective excitation in condensed systems [5][6][7][8][9][10][11][12]. General strategies for the sensitization

• measurement, the sample solution was circulated with a home-made rotation cell with 1 mm optical length. Steady-state absorption spectra were recorded before and after the transient absorption measurement to examine photodegradation of the sample and no permanent change in absorbance was observed. We used 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

• ], constructing supramolecular dye lasers [18][19], protecting fluorophores from photodegradation [20][21] and manufacturing organic luminescent materials [22][23][24]. Also, variations of luminescence have been utilized to obtain information about the hydrophobicity, polarity, and polarizability of the inner

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• which several techniques have been exploited, spanning from oxidation to photodegradation. Tests were performed only with materials CaNS2 and CaNS4, which appeared on average the best absorbents towards p-nitroanilines. The results of the sequestration tests on dyes 6–10 are summarized in Table 2

A semisynthesis of 3'-O-ethyl-5,6-dihydrospinosyn J based on the spinosyn A aglycone

• Kai Zhang,
• Shenglan Liu,
• Anjun Liu,
• Hongxin Chai,
• Jiarong Li and
• Lamusi A

Beilstein J. Org. Chem. 2017, 13, 2603–2609, doi:10.3762/bjoc.13.257

• contrast with spinosad [14]. Spinetoram has been widely applied in insect control and sterilization. Similar to spinosad, spinetoram can be rapidly degraded into natural components by several ways, such as photodegradation and biodegradation [15], suggesting that spinetoram is safe for the environment. In

1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides

• Fei-Fei Xu,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2017, 13, 1994–1998, doi:10.3762/bjoc.13.195

• , including dichloromethane, is sold under the trade name Brom-55 and used as swimming pool sanitizer, as industrial brominating agent for ethylene propylene diene monomer rubber to improve ozone resistance, as additive in plastics to promote photodegradation and as a fungicide to preserve fresh fruits [27

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

• trans-Ner inside the CD cavity. Next, the effect of encapsulation on the Ner photodegradation rate under UVB irradiation was examined. Solid HP-β-CD/Ner complexes were also prepared and the encapsulation efficiency (EE %) was determined. Results and Discussion Phase solubility studies Considering the

• stable conformer) is represented in Figure 4b. The results showed that the formation of the β-CD/trans-Ner inclusion complex is an energetically favorable process and that the inclusion mode is coherent with the experimental NMR results. Photodegradation studies of Ner To the best of our knowledge, no

• studies were performed on the photodegradation of Ner under UV-light. Nonetheless, we can assume that the presence of three C=C double bonds may indicate the susceptibility of Ner to be photodegradable [29]. Therefore, the photostability of Ner was carried out in aqueous solution, in the absence and the

Energy down converting organic fluorophore functionalized mesoporous silica hybrids for monolith-coated light emitting diodes

• Markus Börgardts and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 768–778, doi:10.3762/bjoc.13.76

• alternative, eventually starting from renewable organic materials [8][9]. Other than inorganic luminophores these organic analogues cannot simply be intercalated in a robust inorganic host structure and, therefore, ligating materials are required. Since the host structure should not undergo photodegradation

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• nanosized titanium dioxide (nanoTiO2) applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the

• ][21][22][23][24]. The photodegradation is a technology utilizing the energy of light for decomposition of the contaminants. CD can catalyse or inhibit the photodecomposition of a compound depending on the position of the light-sensitive bonds of the included compound. For instance, photodegradation of

• photodegradation of methylene blue [24], and CD-functionalized Fe3O4/TiO2 was efficient catalyst in photodecomposition of endocrine disrupting compounds, such as bisphenol A and dibutyl phthalate [30]. Producing strong oxidizing radicals (hydroxyl and superoxide radical ions) titanium dioxide is a widely used

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

• irradiation of benzothiazole-squaraines results in a photodegradation process. Rapozzi et al. assume that oxidation probably involves through formation of a π-complex between the electron-rich enamine double bond and molecular oxygen. In comparison to the photo-oxidation of enaminon or other electron-rich

Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

• Sophie Letort,
• Sébastien Balieu,
• William Erb,
• Géraldine Gouhier and
• François Estour

Beilstein J. Org. Chem. 2016, 12, 204–228, doi:10.3762/bjoc.12.23

• prevent their hydrolysis and photodegradation. Thus, many studies were performed to rationalise the outcome of the reaction between CDs and organophosphorus pesticides (compounds 10–13, Figure 4). The influence of CDs on the hydrolysis rate of parathion (10, Figure 4), methyl parathion (11, Figure 4) and

• expand the size of the cavities, resulting in a better hydrolysis inhibition of the pesticides through its deeper inclusion. The formation of inclusion complexes can also modulate the organophosphorus photodegradation rates, but the results strongly depend on the host–guest systems [59][60] (Table 5

• effect of CDs, probably due to a higher steric hindrance around the torus. Later, the effect of native cyclodextrins on the photodegradation of organophosphorus pesticides was evaluated in water containing humic acids [61]. In these conditions, the three native CDs promote the photodegradation of the