Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• spectra were investigated. As explained in the previous section, a similar behavior was observed in the emission spectra with respect to the substitution pattern. In general, a bathochromic shift of the emission was observed in the presence of a dimethylamino group at the 5-position. The bathochromic

• bathochromic shift of 5m is 57 nm and lies between the two emission peaks of 5d and 5k. Therefore, it can be concluded that combining the two substitution patterns leads to this intermediate behavior. Substitution of the 5-π-donor with a π-acceptor group reduced the bathochromic shift from 57 nm to 18 nm

• shift of 5d compared to its regioisomer 5k is 68 nm. This underlines the spectral effect of the π-donor on the 5- or 6-position and the dependence of the distance between the functional group and the uracil core system. In the spectra of 5m, a combination of both situations can be observed. The

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• chiroptical properties with a large change in the absorption spectra and a bathochromic shift in the emission maximum. This system represents a rare example of a multi-output readout system, showing responses in ECD, fluorescence, and CPL activity. The authors later reported a similar system with a bipyridine

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• color of these dyes, as shown by the absorption maxima positions of the substituted indigo derivatives (Table 1) [23][24]. The introduction of the ED (electron-donating) substituents into the para (5,5')- or ortho (7,7')-positions to the electron-donating NH group results in a bathochromic shift of the

• causes a hypsochromic shift of the absorption band, while the presence of the EA substituents at these positions leads to a bathochromic shift (Figure 5). In addition, electron-donating substituents on the nitrogen atom produce bathochromic shifts, while electron-withdrawing groups at this position give

• the electron density on the N atom in the ground state due to the electronic effects of substituents facilitates charge transfer during excitation, which leads to a decrease in the energy of the transition and a bathochromic shift of the absorption band, and vice versa. Photochemistry of indigo

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• derivatives 2b–g showed a slight bathochromic shift mostly in the range of λmax = 333–360 nm, whereas for the nitro-substituted compound 2a a stronger red shift of the absorption maximum was observed, presumably caused by the strong electron-withdrawing property of the nitro group resulting in a more

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• clear evidence of a bathochromic shift and a reduction in the optical band gap. These results support the idea that the introduction of biphenylene linkages may decrease delocalization in the structure. However, despite this reduction, there is still communication between the acene units evident from

• the failure in the formation of the desired target products. Upon comparing the UV–vis absorbance graphs of compounds 28 and 29, POA 29 (λmax = 500 nm), which was obtained through the aromatization of compound 28, exhibited a significant bathochromic shift. These observations further support the

• nearly identical absorption profiles with a maximum absorption at λmax = 515 nm, the incorporation of donor groups in compound 34c led to a noteworthy bathochromic shift with a maximum absorption at λmax = 534 nm. Additionally, it was reported that all three compounds, 34a–c, demonstrated remarkable

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• position (PDIN-B, CN-PDIN-B) with those with a pentafluorobenzyl group (PDIN-FB, CN-PDIN-FB), a bathochromic shift of 0.02 eV is observed when going from the pentafluorobenzyl to the benzyl derivatives. When comparing the derivatives with (CN-PDIN-FB, CN-PDIN-B) and without (PDIN-FB, PDIN-B) a nitrile

• group, a bathochromic shift of 13 nm is observed for PDIN-FB → CN-PDIN-FB, and a bathochromic shift of 13 nm is observed for PDIN-B → CN-PDIN-B. The presence of the nitrile functional group results in a lowering of the energy of the optical band gap, which can be attributed to a higher degree of

Unravelling a trichloroacetic acid-catalyzed cascade access to benzo[f]chromeno[2,3-h]quinoxalinoporphyrins

• Chandra Sekhar Tekuri,
• Pargat Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2023, 19, 1216–1224, doi:10.3762/bjoc.19.89

• spectroscopy. The preliminary photophysical results revealed a significant red-shift in their absorption and emission spectra as compared to the meso-tetrakis(4-methylphenyl)porphyrins due to the extended π-conjugation. Keywords: bathochromic shift; benzo[f]chromeno[2,3-h]quinoxalinoporphyrins; catalysis

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• charge transfer state which results in a bathochromic shift of the absorption towards the visible range [19][20]. Upon light irradiation, the EDA complex may undergo an intramolecular single-electron-transfer (SET) process to produce a radical ion pair (D•+, A•−). To avoid the occurrence of a back

• observed that the addition of DABCO to the solution of 2a induced a bathochromic shift of the absorption spectrum towards the visible region, thus indicating the formation of an EDA complex between these chemical species. Importantly, we also confirmed that indole 1a and 2a do not form a photoactive EDA

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• -base porphyrins 23b–29b in good yields. In addition, their zinc analogues 23c–25c were also obtained in excellent yields by the reaction of free-base porphyrins with zinc acetate. The preliminary photophysical studies of the porphyrin-xanthone dyads show a bathochromic shift in the absorption and

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• data with related previously reported purealidins [19]. While no HMBC correlations were identified for these exchangeable proton signals, the presence of a phenol was further supported by a bathochromic shift that was seen in the UV spectrum of 1 upon addition of base [20]. The bromine atom and phenol

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• significant bathochromic shift as compared to the deprotonated glycine complex (λmax = 458 nm [9]) indicates an elongation of the conjugation chain and formation of the anionic complex which can be considered as a vinylog of the parent glycine derivative (Scheme 2) The anionic species formed in the

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• level of OTT-2 is lower than that of OTK-2, but OTT-2 and OTK-2 have comparable highest occupied molecular orbital (HOMO) energy levels. Consequently, this work reveals that compared to the (D–π)2Ph-type structure, the (D–π)2-type structure exhibits not only a bathochromic shift of the photoabsorption

• . However, the knr-solid/kr-solid value (3.2) of OTT-2 is smaller than that (5.7) of OTK-2, suggesting that the higher Φfl-solid value of OTT-2 is due to the larger kr value compared with that of OTK-2. Therefore, it was found that the (D–π)2-type structure exhibits not only the bathochromic shift of

• -2 than OTK-2, that is, the bathochromic shift of the photoabsorption band from OTT-2 to OTK-2. Conclusion We have developed the (D–π)2-type fluorescent dye OTT-2 and the (D–π)2Ph-type fluorescent dye OTK-2 and evaluated their optical and electrochemical properties. Both in solution and the solid

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• colors of green (524 nm), yellow (576 nm), red (640 nm), and NIR (739 nm) (Figure 3b) [27]. The stronger Lewis acidity resulted in a stronger emission and bathochromic shift when comparing the effects of BCF and B(C6H5)3 on the optoelectronic properties of the organic UV fluorescent material 35DCzPPy (14

Towards new NIR dyes for free radical photopolymerization processes

• Haifaa Mokbel,
• Guillaume Noirbent,
• Didier Gigmes,
• Frédéric Dumur and
• Jacques Lalevée

Beilstein J. Org. Chem. 2021, 17, 2067–2076, doi:10.3762/bjoc.17.133

• [cd]indol-1-ium unit: a bathochromic shift of ≈100 nm was found for these two dyes, as compared to the other dyes investigated in this work, absorbing up to 850 nm. The latter, CBPh3, CI3, and CI10, exhibit a strong absorption above 850 nm (900–1000 nm) and a relatively low absorption at 785 nm

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• , derivatives 4e and 4f bearing an electron-deficient fluoro or trifluoromethyl group show a hyperchromic shift of their bands located between 340 and 380 nm. In case of the electron-donating methoxy substituent (4g), a bathochromic shift was observed. Besides, a new band appeared at 321 nm which may be

Naphthalonitriles featuring efficient emission in solution and in the solid state

• Sidharth Thulaseedharan Nair Sailaja,
• Iván Maisuls,
• Jutta Kösters,
• Alexander Hepp,
• Andreas Faust,
• Jens Voskuhl and
• Cristian A. Strassert

Beilstein J. Org. Chem. 2020, 16, 2960–2970, doi:10.3762/bjoc.16.246

• in the cases of Me and t-Bu compounds, where a gradual bathochromic shift in emission is observed with growing water fraction (Figures S35 and S36, Supporting Information File 1), pointing to a slight charge-transfer character of the emissive state. These compounds show a prominent AIEE upon

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• only slightly red-shifted. The effect of benzannulation in 19 compared to H-SN4 13 as well results only in small differences, which, however, become larger in comparison to hexacyclic heteroacene 22 showing the largest bathochromic shift in the series (Figure S6, Supporting Information File 1). The

Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• . The pH-sensitive properties of all prepared Schiff bases were examined against TBAOH in DMSO, via deprotonation of the OH group in the salicylidene moiety and their reverse protonation was also investigated using TFA. The Schiff bases exhibited a bathochromic shift upon the addition of TBAOH to their

• and 8 > 9 > 10 > 11 > 12 in DMSO, which was consistent with the experimental data (Table 1 and Table S1 in Supporting Information File 1). A solvent effect on the absorption spectra was observed for compound 4 resulting in a bathochromic shift of about 22 nm from PhMe to DMSO, whereas there was only a

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

• bathochromic shift of the 441 nm band accompanied by a typical redistribution of intensity of absorption bands (see Table 1) is detected. At longer irradiation times, the rearrangement processes are reflected by the spectral curves depicted in Figure 3. Crystal packing of the product of the photoinduced

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• benzothiophenone derivatives exhibited better photophysical properties including high quantum yield, brightness and significant bathochromic shift in the emission wavelengths. In short, β-carboline-substituted benzothiophenone derivatives emerged as excellent fluorophores and displayed remarkable photophysical

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

• nanoparticles) or by introducing impurities into the crystal lattice, otherwise known as doping [44][84][85][86]. Semiconductor doping adds additional filled or vacant quantum states to the band structure that lie within the band gap, reducing the Eg and typically resulting in a bathochromic shift in absorption

• via physisorption. However, functionalised molecules and ions can strongly bind through chemisorption by covalent bonds, hydrogen bonding, or electrostatic attraction and have been shown to influence the photophysical properties of TiO2, generally causing a bathochromic shift of the absorption

Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore

• Esteban P. Urriolabeitia,
• Pablo Sánchez,
• Alexandra Pop,
• Cristian Silvestru,
• Eduardo Laga,
• Ana I. Jiménez and
• Carlos Cativiela

Beilstein J. Org. Chem. 2020, 16, 1111–1123, doi:10.3762/bjoc.16.98

• –vis spectra of oxazolones 2 show that the absorption is zero or close to zero. Therefore, the lack of reactivity of species 2 can be related with the absence of the absorption of light. However, the ortho-palladation causes a clear bathochromic shift from compounds 2 to 3 and this results in

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• that p-substituents (trans-3, trans-4, and trans-7) enabled a higher value of molar extinction coefficients, in comparison to o-substituted compounds (trans-5 and trans-6). The cyano-substituted compound trans-6 showed the largest bathochromic shift, in regards to the methyl and methoxy-substituted

Aryl-substituted acridanes as hosts for TADF-based OLEDs

• Naveen Masimukku,
• Dalius Gudeika,
• Oleksandr Bezvikonnyi,
• Ihor Syvorotka,
• Rasa Keruckiene,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 989–1000, doi:10.3762/bjoc.16.88

• accompanied by intermolecular CT state relaxation. Such emission is evidenced by solvatochromic effects, i.e., a bathochromic shift of the emission peak due to the change of the environment to a more polar one. By replacement of the solvent toluene with THF, the solution of 4 exhibited a bathochromic shift of