Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• estimated from the change of substrate concentration over the first 30 min reaction time. Top: UV–vis absorption spectra for the two dimeric reductants in THF emphasizing (a) the different positions of the relatively strong absorption peaks and (b) the presence of a low-energy shoulder in the spectrum of (N

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• % yields, respectively. When comparing compounds 25a and 25b, UV–vis and fluorescence studies (λmax = 500 nm, λem = 502 nm, Φem = 0.45 for 25a; λmax = 513 nm, λem = 517 nm, Φem = 0.26 for 25b; λmax = 442 nm, λem = 444 nm, Φem = 0.97 for 9,10-bis((triisopropylsilyl)ethynyl)anthracene – blue-colored) provide

• 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

• ranging between 45% and 60%. The last step of the sequential reactions is the aromatization step and the target POAs 34a–c were obtained in yields between 80–84%. UV–vis investigations conducted on compounds 34a–c revealed absorption bands that align well with acene structures. While 34a and 34b displayed

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• respect to the incident photon energy (hν) and the hν axis. This approach allowed for a precise determination of the IPPE, facilitating a deeper understanding of the electron behavior and electronic properties of the studied materials. UV–vis absorbance, photoluminescence (PL), and phosphorescence

• spectroscopy were used to study the optical properties of the compounds under investigation. For UV–vis absorbance spectra, solutions or films of the compounds were analyzed using an Avantes AvaSpec-2048XL spectrometer, which allowed us to assess the compounds’ absorption characteristics across the ultraviolet

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• lithiation of 7 and following reaction with dimesitylboron fluoride in 85% yield (Scheme 1). Photophysical properties The UV–vis absorption and fluorescence spectra of DMB-TT-TPA (8) were recorded in THF (Figure 1 and Table 1) [38]. It showed maximum absorption and emission wavelengths of 411 and 520 nm

• investigate the absorption properties and theoretical band gap (Table 3). The optical band gap value (Eoptic) was calculated to be 2.06 eV, considering the λonset (605 nm) of the UV–vis curve. The calculated absorption maximum was centered at 470 nm (Figure S4 in Supporting Information File 1), which was

• found to be in a good agreement with the experimentally determined UV–vis spectrum. Conclusion A small fluorophore molecule, DMB-TT-TPA (8), containing dimesitylboron as an acceptor and triphenylamine as a donor linked through a thieno[3,2-b]thiophene core having a 4-MeOPh group, was designed as a D–π–A

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• ), coupling constant, number of atoms. UV–vis absorption spectra were recorded on a Mapada Instruments UV3100PC spectrophotometer. Mass spectra were recorded on an Agilent 1200/6210 high-resolution mass time-of-flight (TOF) LC–MS spectrometer. Reactions were followed by thin-layer chromatography (TLC

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• detect, if the two polymorphs show different catalytic activity, as in the following investigations the amorphic powder was used. Spectroscopic and electrochemical characterization The Co(II) complex 1 was characterized by UV–vis absorption spectroscopy in N,N-dimethylacetamide (DMA), as it was the

• UV–vis absorption of a typical photocatalytic solution under irradiation were monitored over a period of four hours (Figure S12 in Supporting Information File 1) and the spectra show the development of a new broad band at 590 nm, reaching its maximum intensity after 2.5 h. This could be due to the

• drawing of crystal polymorph 1a (left) and 1b (right), shown at the 50% probability level. Hydrogen atoms and co-crystallized solvent molecules are omitted for clarity. UV–vis absorbance of complex 1 in DMA. Inset: zoom-in of the 500–800 nm range to visualize the low-intensity bands associated with metal

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• stability in aqueous medium. Thus, the electronic absorption spectra of hdz-CH3 and hdz-NO2 were recorded in a 10% DMSO/buffer solution (pH 7.4) immediately after preparation and at regular time intervals. The UV–vis spectrum of hdz-CH3 between 250 and 450 nm (Figure 6A) shows two multicomponent absorptions

• registering the UV–vis spectra of a series of hdz-NO2 10% DMSO/buffer (acetate, phosphate or Tris-HCl) solutions with different pH values, ranging from 3.8 to 8.2 (Figure 7A). By plotting the absorbance at λmax as a function of pH and then fitting the curve with a sigmoidal function (Figure 7A, inset), an

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• , thin film, and solid powder. As shown in Figure 2a, the UV–vis absorption spectrum in diluted toluene solution displays intense absorption peaks in the high energy region (<380 nm) and a much weaker absorption peak at 508 nm attributed to the π–π* transition of the conjugated aromatic backbone and

• , featuring no significant vibronic structure, and a considerably large Stokes shift of 140 nm. The UV–vis absorption and PL spectra of spin-coated films were similar to those of dilute solutions. Based on the onset energy of this UV–vis spectrum, the optical band gap (Egopt) was estimated to be 2.04 eV

• and emission behaviors were investigated in several solvents as illustrated in Figure 3a. The results showed that, while the UV–vis absorption spectra were nearly unaffected by the nature of the solvent due to the LE nature, the emission spectra exhibited a noticeable positive solvatochromism, with

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• PC61BM (VI, Figure 7) and that of the 12 derivatives with 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene, VII, Figure 7), since we have previously found that these dopant class/SC combinations often react on a timescale suitable for monitoring using UV–vis–NIR spectroscopy (1H derivatives do

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• the aryl group at the meso-position of the dipyrrin moiety. Compound 40 was tested for sensing metal ions, and while no significant changes were observed with most cations, the addition of Cu(II) resulted in a colour change. UV–vis spectroscopy and mass spectrometry confirmed the 1:1 copper(II

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

• -FB, and CN-PDIN-B. b) Normalized solution UV–visible spectra using ethyl acetate as the solvent. c) UV–vis spectra for films on quartz substrates where films were cast from 1 mg/mL solutions using ethyl acetate as the solvent. a) PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-B structures with their

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• % B in 19.5 min and then maintaining 100% B for 5 min, flow rate 0.6 mL/min, UV–vis detection 200–640 nm) connected to a MaXis ESI-TOF mass spectrometer (Bruker) (scan range 100–2500 m/z, capillary voltage 4500 V, dry temperature 200 °C). NMR spectra were recorded at 25 °C on a Bruker (Billerica, MA

• purified on a flash liquid chromatography (Flash and prep HPLC, C-850, UV/ELSD detector, UV–vis/UV scanning) equipped with a Gemini C18 (10 µm, 250 × 50 mm). Equivalent fractions from the three repeated runs were combined to give compounds 6 (1.19 mg, white solid, tR = 4.86 min), 8 (286 mg, white crystal

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• and LUMO energy levels indicates the potential suitability of 4BGIPN material for application not only as emitter in the emitting layer but also as an electron transport layer in the fabrication of OLEDs. Photophysical properties and theoretical considerations UV–vis and photoluminescence (PL) spectra

• for 4BGIPN are shown in Figure 4 and Figure 5 while data in various media is collected in Table 2 and Table 3, respectively. UV–vis absorption spectra of 4BGIPN show a strong π–π* intraligand transition (IL, benzoguanidine) at 290 nm with ε = 42000 M−1cm−1. Unlike 4CzIPN, we do not observe any

• vibronically resolved carbazole absorption peaks which are commonly present at 325 nm [15]. Similar to 4CzIPN [14][15], the UV–vis profile has two broad regions: localized charge transfer (loCT) over 320–380 nm region with ε up to 14000 M−1 cm−1 and a delocalized charge transfer (deCT) broad shoulder over the

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

• aldehydes and dimedone in chloroform at 65 °C. The optical properties of the newly prepared porphyrins have been investigated by using UV–vis and emission spectroscopy and the results are presented in this paper. Results and Discussion Synthesis The required precursors, copper(II) 2,3-diamino-5,10,15,20

• copper(II) porphyrins 3–8. Finally, the structures of all newly synthesized benzo[f]chromeno[2,3-h]quinoxalinoporphyrins 3–16 and benzo[f]quinoxalinoporphyrin 17 were assigned on the basis of IR, 1H and 13C NMR, and HRMS data analysis. Photophysical characteristics The UV–vis spectra of the newly

• reported in hertz (Hz). Infrared (IR) spectra of the synthesized compounds were recorded in film or KBr on Perkin Elmer IR spectrometer and absorption maxima (υmax) are given in cm−1. UV–vis absorption and fluorescence spectra were recorded on an Analytik Jena’s Specord 250 UV–vis spectrophotometer and a

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• potential to alter the physical properties (e.g., stability, solubility, UV–vis absorption) of an ylide, as well as bias a Lewis base’s σ-hole selectivity through σ-hole blocking, which represent emerging avenues for tuning an ylide’s reactivity and improving its reaction outcomes. Review 1 Halogen bonding

• to changes in an ylide’s UV–vis absorption profile, or to its overall basicity or nucleophilicity, both of which could lead new and unexpected reactivity. The first example that specifically invoked electron donor–acceptor complexes of iodonium ylides was reported in 2018 by Wang and co-workers [122

• a near identical mechanism to that of Wang (Figure 8). Strong evidence for formation of an initial EDA complex was found when measuring the UV–vis absorption spectra of 39, alone and in the presence of 32. The latter showed a significant absorption red shift, which implied a structural change in 39

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• at 0.6 mL/min and the UV–vis detection made at 210 nm and 190–600 nm. The isolates were analyzed on a MaXis ESI-TOF (time-of-flight) mass spectrometer (Bruker Daltonics) for the HRESIMS data, in the positive ionization mode. This was coupled to an Agilent 1260 series HPLC–UV system (Agilent

• min, 5% B to 100% B within 19.5 min and at 100% B for 5 min. The flow rate was maintained at 0.6 mL/min and UV–vis detection made at 200–600 nm. The calculation of the compounds’ molecular formulas was performed using the Smart Formula algorithm of the Compass DataAnalysis software (Bruker Daltonics

• deuterated solvents CD3SOCD3 and CD3OD, respectively, were used in 13C NMR spectra calibration. An Anton Paar MCP-150 Polarimeter (Graz, Austria), was used to measure the optical rotations on a 100 mm path length and sodium D line at 589 nm. The sample concentration was 1.0 mg/mL in MeOH. A Shimadzu UV–vis

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• . This is further supported by the inability of *PC3 (E1/2 = −1.76 V vs SCE) to reduce 1d in the absence of DBU although this is thermodynamically favored. Additionally, the UV–vis–NIR absorption spectrum of a mixture of PC1•− and 1d does not fit the mathematical sum of absorption spectra of both

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• capability of the PTZ and NI moieties, respectively, by oxidation of the PTZ unit, or by using different aryl substituents attached to the NI unit. This tuning effect was manifested in the UV–vis absorption and fluorescence emission spectra, e.g., in the change of the charge transfer absorption bands. TADF

• were studied by steady state UV–vis absorption spectroscopy, transient photoluminescence spectroscopy, nanosecond/femtosecond transient absorption spectroscopy, electrochemistry, as well as DFT/TDDFT computations. We observed experimental evidence for the spin–vibronic coupling effect in the TADF

• by 1H NMR, 13C NMR, and HRMS spectra (Experimental section). UV–vis absorption and fluorescence emission spectra The UV–vis absorption spectra of the compounds were studied (Figure 1 and Figure S29 in Supporting Information File 1). For the compounds without an oxidized PTZ unit, there are

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• using a pressure cell and a UV–vis competition assay with an azo-dye (4-((4-hydroxyphenyl)azo)-1-naphthalenesulfonic acid (7) Figure 4) [15] as an indicator. The UV–vis spectrum of 7 changes on binding to cyclodextrins and we can thereby indirectly monitor the binding of CO2 to the CD by observing the

A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• detection of heavy metal ions. Results and Discussion The interactions of G with TMeQ[6] UV–vis spectroscopy analysis The binding interaction between G and TMeQ[6] in aqueous solution was studied using UV–vis absorption spectroscopy. Figure 2a shows that the absorbance of G decreases with the addition of

• , which is an exothermic reaction (enthalpy-driven). The results show that the binding ability of G and TMeQ[6] is strong, and the ratio is 1:1. The results are consistent with those obtained by UV–vis spectroscopy and fluorescence spectroscopy. Single-crystal X-ray diffraction analysis The crystal

• . The host–guest interaction between TMeQ[6] and G was investigated using a UV-2700 dual-beam ultraviolet–visible (UV–vis) spectrophotometer and Varian Cary Eclipse fluorescence spectrophotometer at room temperature [41]. At U = 550 V, slit = 5/5, different concentrations of G were added to the TMeQ[6

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• Büchi Reveleris® X2 flash chromatography system equipped with a UV–vis/ELSD detector and Reveleris Flash pure cartridges (12–40 g, 35–45 μm, 53–80 Å) or puriFlash® Alumine N 32/63 µm cartridges (12 g). The reaction pathways were calculated [41] with the Gaussian 16 rev. C.01 program, using the B3LYP

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• Co., Japan), Sephadex LH-20 (Amersham Biosciences), and YMC gel ODS-A-HG (particle size 40–60 μm; YMC Co. Japan). A Saipuruisi chromatograph with a semi-preparative high-pressure infusion pump (SP-5030) and a semi-preparative UV–vis dual wavelength detector (UV200) were utilized for RP–HPLC. A YMC

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• -conjugation of 1,8-bis(dimethylamino)naphthalene (DMAN) fragments through a butadiyne linker and a donor–acceptor aryl–C≡C–DMAN conjugation path. The conjugation path can be “switched” simply by protonation of DMAN fragments. X-ray diffraction, UV–vis spectroscopy and cyclic voltammetry are applied to analyze

• us to undertake the current study. X-ray crystallography, UV–vis spectroscopy and cyclic voltammetry were applied to analyze the extent of π-electron conjugation and the efficiency of the particular donor–acceptor conjugation path in chromophores 5. Results and Discussion Synthesis The target

• packing of almost linear molecules (Figure S69, Supporting Information File 1). UV–vis spectra and redox properties As stated above, oligomers 5 are cross-conjugated π-systems. For cross-conjugated structures, the main question is about the preferential conjugation path. For oligomers 5, two different

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• UV–vis spectrophotometer. ECD spectra were acquired on a JASCO J-1500 circular dichroism spectrometer. FTIR spectra were obtained using a PerkinElmer FTS FT-IR spectrophotometer. NMR spectra were obtained on a Bruker NEO 500 MHz NMR Ultra Shield. Chemical shifts are referenced in parts per million (δ

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

• both UV–vis and nuclear magnetic resonance (NMR) spectroscopy [29]. In particular, the optical absorption spectra of substrate 2a (green dotted line), DABCO (red dotted line), and the solution containing both 2a and DABCO (blue line) were recorded in acetonitrile (Figure 2). Specifically, it was