C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• introduction of substituents to the seven-methine carbon chain of Cy7 influences its optical properties and ability to interact with biomolecules. A one-pot synthesis of γ-acyloxy-Cy7 from renewable furfural, simple anhydrides, and a quaternary ammonium salt under smooth conditions was reported (Scheme 63

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• side. The energy barrier was calculated to be 66.7 kcal mol−1, indicating MC3 is highly conformationally stable. The optical properties of the synthesized macrocycles were investigated in dichloromethane (Figure 3). The precursors 3a,b show intense absorptions with maxima at 425 nm and 395 nm

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• -linear optical properties, switching with two-photon absorption of near-IR wavelengths [3][27]. This could open the way to laser-storage devices and to application in biological systems, where longer wavelengths are preferred due to improved tissue penetration [28]. When the push–pull character is not so

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• oligomers using planar chiral tetrasubstituted [2.2]paracyclophane as chiral crossing units were prepared, in which π-extended conjugated systems were folded in either two or three places. The oligomers exhibited good optical properties such as PL and CPL properties with good ΦPL values (>0.6) and |glum

Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads

• Issei Fukunaga,
• Shunsuke Kobashi,
• Yuki Nagai,
• Hiroki Horita,
• Hiromitsu Maeda and
• Yoichi Kobayashi

Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121

• shown in Supporting Information File 1. Energy levels and steady-state optical properties Time-dependent density functional theory (TD-DFT) calculations were performed to gain insights into the electronic structures of Pe–PTZ derivatives at B3LYP/6-31+G(d,p) level of theory (Figure 2) [18]. The

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• largest cyclic array in the series. The oxidative fusion reaction with [bis(trifluoroacetoxy)iodo]benzene (PIFA) afforded a cyclophane-type aza[5]helicene-incorporated macrocycle, the structure of which was unambiguously revealed by X-ray diffraction analysis. Its optical properties have been investigated

• an aza[5]helicene-incorporated macrocycle. The resulting cyclophane-like structure and its optical properties have been analyzed in detail. Results and Discussion Synthesis and characterization Synthesis We obtained o-phenylene-pyrrole-thiophene hybrid icosamer 4 during our attempt to synthesize

• two NH sites remained uncoordinated due to steric hindrance. Non-covalent interaction (NCI) plot analysis revealed distinct intramolecular π–π dispersion interactions between the two aza[5]helicene moieties (green surface in Figure 4b) [29][30][31]. Optical properties The electronic absorption and

Highly distinguishable isomeric states of a tripodal arylazopyrazole derivative on graphite through electron/hole-induced switching at ambient conditions

• Himani Malik,
• Sudha Devi,
• Debapriya Gupta,
• Ankit Kumar Gaur,
• Sugumar Venkataramani and
• Thiruvancheril G. Gopakumar

Beilstein J. Org. Chem. 2025, 21, 1496–1507, doi:10.3762/bjoc.21.112

• electronic and optical properties of switchable states. The applicability of molecular switches relies on the efficiency, reversibility, and the half-life associated with different non-equilibrium states. Typically, the half-life of the Z isomer of AB is a few days [17]. Chemical modifications of AB

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• design strategies for constructing helically twisted or planarized chiral π-conjugated systems with tunable optical properties, thereby paving the way for the development of multifunctional materials in advanced photonic and electronic technologies. In 2021, Viglianisi’s group synthesized a series of

Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds

• Lidia Zaharieva,
• Vera Deneva,
• Fadhil S. Kamounah,
• Nikolay Vassilev,
• Ivan Angelov,
• Michael Pittelkow and
• Liudmil Antonov

Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105

• resistance [1][2][3][4]. In addition to their conventional use, azodyes have unique optical properties, defined by the E/Z isomerization [5][6] and by the tautomeric proton exchange [3][7][8][9][10][11], when a OH or NH group is present on a suitable position in the molecule. Both processes are strongly

Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• their size, surface defects, and functional groups, which can be engineered to tune their optical properties. Accordingly, their emission spans a broad range of wavelengths, from ultraviolet to the visible region, allowing for the potential application in an impressive range of applications, such as

• via hydrothermal treatments have an amorphous structure. The optical properties of the prepared CDs were thus investigated by UV–vis absorption spectroscopy. The obtained spectra (Figure 1) showed three main absorption bands located at 225–235 nm (assigned to, according to the literature, the π–π

Synthesis of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones by domino C–N coupling/hydroamination reactions

• Ruben Manuel Figueira de Abreu,
• Robin Tiedemann,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2025, 21, 1010–1017, doi:10.3762/bjoc.21.82

• Abstract A variety of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones were prepared by a combination of Sonogashira reaction and subsequent cyclization by domino C–N coupling/hydroamination reaction. The optical properties (UV–vis absorption and fluorescence) depend on the substitution pattern of the compounds

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

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

• )bimane (DMOCDO10) and syn-(Me,Me)bimane (DXABIM10) [26], a room temperature structure of Me4B (TNZBCO10) [27], and a planar syn-(H,ethynyl)bimane (WAYHEJ) [28]. Optical properties The optical properties of the three bimanes were measured to investigate differences in their excited state properties, as

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

• have been extensively studied in the literature such as bridged Eosin Y 37 [44], BODIPY 38 [45], and dibenzothiazole 39 (Figure 5) [46]. Indeed, organic dyes, with their inherent advantages of low toxicity, environmental friendliness, and tunable optical properties, represent a promising alternative

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• by scanning electron microscopy. The intriguing optical properties of BPP and its derivatives may lead to their application as fluorophores. Keywords: benzo[rst]pentaphene; intramolecular charge transfer; nanocrystals; photoluminescence; polycyclic aromatic hydrocarbon; Introduction Polycyclic

• improving the stability of inverted perovskite solar cells [23]. On the other hand, benzo[rst]pentaphene-5,8-dione (BPP-dione) is known as an oxidation product of BPP [24][25], but to the best of our knowledge, the detailed optical properties of this BPP derivative have not been previously described in the

• Supporting Information File 1), suggesting that the BPP core can lead to such rod-shaped crystals and nanowires. Conclusion In summary, we achieved a facile synthesis of BPP-OiPr 3 and studied its optical properties in comparison to pristine BPP 2 and its oxidation product BPP-dione 4. Both BPP-OiPr 3 and

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• the optical properties of 18 in CHCl3 (c = 100 μM) by measuring its UV–vis absorption spectrum as well as its excitation and emission spectra. The UV–vis spectrum of 18 showed two absorption peaks at 334 nm and around 375 nm (gray solid line). When excited at 375 nm, the emission spectra of 18

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• new, structurally-related series of π-conjugated aromatic compounds (Figure 1) based on a simple triphenylene core and evaluating the mesomorphic and optical properties. Specifically 1,2,4-trifluoro-6,7,10,11-tetraalkoxy-3-(perfluorophenyl)triphenylenes (Fn, Figure 1), bearing a terminal fluoroarene

• optical properties of these compounds by comparing the properties of Fn with those of partially fluorinated PHn and non-fluorinated BTPn. Such comparison is critical for optimizing materials for specific applications. Second, the presence of this terminal fluoroarene group provides a basic platform to

• , Tables S1–S3), TGA (Figure S35, Table S4), POM (Figure S36), DSC (Figures S37, S38, Table S5), S/WAXS (Figures S39–S43, Table S6), optical properties (Table S7), and DFT (Figure S44, Table S8). Supporting Information File 50: Experimental part. Acknowledgements B.D. thanks the CNRS and the University of

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• featuring the CD-based rotaxane framework by implementing a certain level of structural control at the same time. In 2013, Anderson and co-workers synthesized a conjugative polymer, which was included by β-CDs, and investigated their optical properties and thermal stabilities (Figure 13A) [81

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• pyridine as an acceptor. The introduction of additional substituents to stilbazole makes it possible to change the optical properties of this molecular framework within a wide range [16][17][18][19]. This approach has found many applications in the synthesis of compounds that are used in various optical

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• values of absorption (λonset), and little difference was found with values of 1.47 eV for 3b and 1.46 eV for 3a and 3c. It is noted that the optical properties did not show a significant change upon altering the alkyl chains which indicates that different alkyl substituents have a minimal effect on the

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• and Suzuki–Miyaura cross-coupling reactions followed by Brønsted acid-mediated cycloisomerisation. The developed methodology tolerates various functional groups and leads to moderate up to quantitative yields of the final products. The impact of different functional groups on the optical properties

• -based benzo[f]quinazoline-1,3(2H,4H)-diones C [65]. Furthermore, optical properties were analysed by UV–vis and fluorescence spectroscopy. Results and Discussion Synthesis Our strategy for the synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones is based on a four-step sequence and relies on a combination

• various functional groups. The optical properties of as-prepared derivatives were investigated by steady-state absorption and photoluminescence spectroscopy. The photophysical properties are strongly altered by the presence N,N-dimethylaniline functional groups on the scaffold, which leads to strongly

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

• . Synthesis of 3-arylbenzofuran-2(3H)-ones. Synthesis of 2-hydroxybenzophenones. Gram-scale experiment. Control experiments. Optimization of reaction conditions.a Optical properties of the compounds 4aa–ma. Values of [EE(λ) × I(λ)] used in calculating the SPF. Supporting Information Supporting Information

• File 10: Characterization data of compounds 3aa–ma, 4aa–ma, and 5. 1H and 13C NMR spectra of 3aa–ma, 4aa–ma, and 5; single crystal data of 4ja, 4fb, and 4ma; UV–vis absorption spectra and optical properties of 4aa–ma. Acknowledgements The authors acknowledge Dr. Sudip Gorai, BARC, for his help in

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• outer side (in-out-ts), but the thermodynamically stable final product is a regioselective “in-in” adduct, i.e., compound 6a. Optical properties Absorption and emission spectra of 6a were measured in CH2Cl2 (Figure 5). The conjugation is changed and a highly-twisted macrocyle forms by the double azide

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• outstanding optical properties [43]. Herein, we present for the first time three new mono-, di-, tri-dipyrromethane appended truxene derivatives with the intention to explore them for future sensing and/or binding properties. Results and Discussion To achieve our goal towards the construction of truxene

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• (disubstitution) and non-symmetrical (monosubstitution) DPP derivatives are formed in excellent overall yields. The optical properties of the newly synthesized compounds are also discussed. The new platform may be useful for bioorthogonal chemistry. Keywords: diketopyrrolopyrrole; fluorescent dye; nucleophilic

• spectra are very similar. These results indicate that substituents with different functional groups can be attached to DPP 2 without significant modification of their optical properties. The observed Stokes shifts for dyes 3 and 4 averaged in the range of 60–70 nm. All compounds exhibited high

• . Additionally, it is crucial to highlight the chemical versatility of compound 2, which allows the attachment of various functional units without significantly altering its optical properties. This versatility holds significant promise in the design and synthesis of innovative molecules tailored for specific