Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• from benzene (53a), naphthalene (53b), and anthracene (53c) with compound 52, the desired target azaacenes 54a–c were successfully obtained in yields ranging from 68% to 84% (Scheme 11). As anticipated, there was a notable red shift observed from 54a to 54c, which can be attributed to the expansion of

• 616 nm. Based on the photophysical properties of compounds 54a and 54b, which were synthesized in the previous study (Scheme 11), it is evident that the addition of the second biphenylene-fused pyrazine group to the structure leads to a substantial red shift towards the NIR region. This observation

• complexation step to isolate stable BF2 complex of 69, likely attributable to solubility issues encountered with substrate 69, prevented the incorporation of the acene backbone into the structure. Consequently, the anticipated red-shift in the absorption spectrum could not be observed as expected. Boron-doped

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

• 10 000 cd m−2, electroluminescence ranging from blue to yellow, maximum current of 15 cd/A and higher EQE than 7%. Pyridine-3,5-dicarbonitrile-based TADF materials exhibit different visible light emission spectra (Figure 1). Recently, Chen and Lu reported two new orange-red/red TADF emitters composed

• compound 8 had a slight impact on its red-shifted absorption spectra in comparison to that of other compounds (Figure 2a,b and Table 1). The photoluminescence spectra of toluene solutions of the compounds are characterized by non-structured shapes typical for ICT emissions (Figure 2c and Figure S1 in

• results of CV measurements were used to obtain the ionization potential (IPCV) and electron affinity (EACV) values of the compounds 6–9. These values were obtained using the following equations: IPCV = e (Eonset,red − Fconset + 4.8), EACV = e (Eonset,ox − Fconset + 4.8) [7]. The IPCV values fall in a

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• : GalN; orange: GlcN; green: GlcNAc; red: ManN. Synthetic IRMPD spectrum (grey trace) generated on the basis of a high resolution endogeneous experimental spectrum of GlcN (black trace) from dataset 1 using additional white noise: 10%; linear signal amplitude modulation: 5%; downsampling coefficient: 2

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

• atmosphere (Figure 4, red curves). In DMA, the electrochemical behavior changed only moderately, suggesting that the reduced complex 1 does not react promptly with carbon dioxide under these conditions. On the other hand, when a 5:1 mixture of DMA/triethanolamine (TEOA) was used as the solvent, a significant

• -centered d–d transitions. Cyclic voltammetry of complex 1 in 0.1 M TBAPF6 solution of (a) DMA and (b) DMA/TEOA 5:1 (v/v). Black curves are registered under Ar and red curves are recorded under CO2 atmosphere. A glassy-carbon disk was used as the working electrode and the internal references used are (a

• ) ferrocene and (b) decamethylferrocene. Scan rate was 100 mV s−1. Time evolution of CO (blue squares) and H2 (red triangles) with the power functional fitting (blue and red curve, respectively). Data were collected for photocatalytic tests in 5 mL DMA/TEA 7:1, [PS] = 0.5 mM; [1] = 0.025 mM; [BIH] = 10 mM

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• ≈3.5 Å for all mesophases. Absorption and photoluminescence (PL) of 1 and 2 are presented in Figure 3 for solution and spin-coated film. Compound 1 shows the three well-defined bands typical of perylene absorption and PL in solution. The absorption becomes broader and the PL destructured and red

• considered. The parameters µ0 and γ implicitly include a monoenergetic trap distribution and can be obtained from fitting the SCLC regimes of the experimental J–V curves. The fits for each device are shown as red solid lines in Figure 6, and the values of µ0 and γ displayed in Table 3 were used to calculate

• absorption. AFM images of spin-coated films of compound 1 (a, c) and compound 2 (b, d) on PEDOT:PSS (a, b) and Al (c, d). Log–log plot of the J–V curves of the hole-only (a,b) and electron-only (c,d) of 1 (a,c) and 2 (b,d). The open circles are the experimental data, and the red solid lines indicate the

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• importance of specific substitutions. While Qx44b demonstrated favorable properties such as a superior dipole moment, narrow bandgap, and red-shifted absorption, the reduced charge transfer rate presented a challenge. This analysis emphasizes the need for a delicate balance between desirable electronic

• properties and efficient charge transfer dynamics [48]. Arunkumar and colleagues demonstrated the utilization of indolocarbazole-Qx systems named ICZS4. The comprehensive investigation of ICZS4's optoelectronic properties highlighted its potential for high-performance DSSCs. The small energy gap, red-shifted

• versatility of quinoxaline derivatives in tailoring the emission properties of TADF materials. The vacuum deposited OLEDs based on Qx63 and Qx64 emitted yellow and red light, achieving EQEs of 17.3% and 15.6%, respectively [63]. You and co-workers reported the strategic design of a series of butterfly-shaped

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

• Frontier Research Center, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand 10.3762/bjoc.19.122 Abstract Herein, we report the synthesis and characterization of an efficient ambipolar charge-carrier-transporting deep-red fluorophore (TPECNz) based on a donor–acceptor

• twist angle between the D and A units, a strong electron deficiency of the Nz unit, and electron-donating and hole-transporting natures of carbazole, TPECNz exhibits a strong deep red emission (λem = 648 nm) with a high fluorescence quantum yield of 96%, outstanding thermal property (Tg = 236 °C), and

• ambipolar charge-carrier-transporting property with a decent balance of mobility of electrons (1.50 × 10−5 cm2 V−1 s−1) and holes (4.42 × 10−6 cm2 V−1 s−1). TPECNz is successfully employed as a non-doped emitter in an OLED which displays deep red electroluminescent emission peaked at 659 nm with CIE

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

• this work (new compounds in red). Crystallographically characterized molecules related to DMBI dimers. Molecular structures from the single crystal structures of 1b2 (two crystallographically inequivalent molecules, left and center) and 1h2 (right), shown with 50% thermal ellipsoids and excluding

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• comparisons between two groups. Dunnett’s test was used for multiple comparisons. P < 0.05 was considered statistically significant. Structures of compounds 1–7. Key HMBC (red arrows), H2BC (black bold lines), and COSY (blue bold lines) correlations in 1 and 2. a) Simplified model structures 1′ and 2′ for

• GIAO and TD-DFT calculations. b) Comparison of experimental ECD spectra of 1 (gray solid line) and 6 (black dotted line) with the Boltzmann-weighted spectra computed for 1′ (red dashed line). c) Comparison of the experimental ECD spectra of 2 (gray solid line) and 7 (black dotted line) with the

• Boltzmann-weighted spectra computed for 2′ (red dashed line). Key HMBC (red arrows), H2BC (black bold lines), and COSY (blue bold lines) correlations in compounds 3 and 4. Comparison of experimental (black solid line) and calculated (red dashed line) ECD spectra of 3. Anti-inflammatory effects of isolated

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• [24], and the combination of DMAPP and IA-1 that was previously reported to yield the natural substrate of 2MIBS 2-Me-GPP [26], only two substrate combinations (DA-4 + IA-1 and DA-5 + IA-1) gave access to analogs of 1. The production of terpenoids by FPPS and 2MIBS is indicated by the red plus signs

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• potential (MESP) maps of two such complexes are shown in Figure 6. It is noteworthy that the intensity of the red color indicative of the negative charge density is maximum around the Cu atom conferring a nucleophilic character on it. Thus, the reaction is initiated by the nucleophilic attack of the NHC–Cu

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• viridis [14][15][16]. Only few terpene synthases have been characterised from other organisms, including enzymes from insects [17], octocorals [18][19], red algae [20][21], and amobae [22][23]. Despite these previous efforts, for many known terpenes still no terpene synthases catalysing their formation

• -α-eudesmol synthase from S. viridochromogenes [29][30]. In order to expand the knowledge about terpene synthase catalysis, fifteen uncharacterised terpene synthase homologs as listed in Table 1 were selected for further studies from different branches of the tree (indicated by red arrows in Figure 2

• branches indicate groups of homologous sesquiterpene synthases, green branches indicate groups of homologous diterpene synthases, and purple branches indicate groups of homologous sesterterpene synthases from which at least one representative was functionally characterised. The red arrows highlight enzymes

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

• exhibits a featureless yellow CT-type luminescence with λmax = 525 nm that is 44 and 25 nm red-shifted compared to 4CzIPN (λmax = 481 and 500 nm in Zeonex and MCH, respectively) [12]. The solution photoluminescent quantum yield (PLQY) of 4BGIPN is 46% under inert atmosphere and decreases down to 18% in

• the benzoguanidine moieties around the central benzene ring. Representative example for the torsion angle α is shown in red; (c) Crystal structure for compound 4BGIPN in triclinic form; (d) packing diagram with key geometrical parameters and intermolecular contacts shown as a cyan dashed line; (e

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

• other materials applications [4][5][6][7]. Among the previously synthesized synthetically modified porphyrinoids, β,β’-fused meso-tetraphenylporphyrins have gained a considerable importance because of their red-shifted absorption and emission due to the extended π-conjugation. In particular, β,β’-fused

• newly prepared copper(II), free-base and zinc(II) benzo[f]chromeno[2,3-h]quinoxalinoporphyrins displayed a significant red-shift in their Soret and Q-bands by ≈20–30 nm as compared to their corresponding meso-tertakis(4-methylphenyl)porphyrins (Cu-TMPP, Soret band at 416 nm; TMPP, Soret band at 419 nm

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

• weakening in the host/donor R–X bond, and an accompanied decrease in the HOMO–LUMO gap which may be experimentally observed as a red-shift in the vibrational frequency [46][47][64][65]. 1.2 Halogen bonding in monovalent iodine The σ-holes expressed by both molecular iodine and other organoiodine compounds

• 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

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

• bearing indolocarbazole electron donor and benzothienopyrimidine electron acceptor moieties (Figure 14A and B) [72]. In general, three possible pathways can lead to catalyst deactivation and thus, kinetically limit the overall photon economy (Figure 14C, red arrows). Firstly, both photoinduced electron

• the distinctive absorption band (λmax = 802 nm) of PC1•− (electrochemically generated) in the absence of light, this absorption band rapidly vanished upon irradiation with red light (λmax = 630 nm), corroborating *PC1•− as the key catalytic species. The rate constants for SET from *PC•− to 1d were

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• carbonyl groups of the urea fragment are observed (Figure 4). Values of spin–spin interaction constants 3JCH equal to 5.3–6.0 Hz indicate the cis-orientation of the vinyl proton and the carbonyl (for 4a, blue) or the carboxyl group (for 5a, red) relative to the double bond [24][25][26]. The values of spin

• –spin interaction constants of other doublets (2JCH = 1.3–1.5 Hz) indicate the position of the carboxyl (for 4a, red) or carbonyl (for 5a, blue) groups through two bonds relative to the olefinic proton. The structure of compound 5a was additionally confirmed by X-ray structural analysis data (Figure 5

• synthetic bioactive 1,3-thiazine and imidazothiazolotriazine derivatives with high antiproliferative activity. 1H NMR spectra of the starting compound 1d (a) and the reaction mixture after 1.5 (b) and 4 (c) hours in DMSO-d6 (the colored signals correspond to the protons shown in red in Scheme 4). 1H NMR

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

• strongly quenched and red-shifted in polar solvents, as compared to that in CHX and HEX. The higher polarity solvents can stabilize the CS state, and the energy of CS state will decrease. As a result, the emission band will be red-shifted and the fluorescence intensity will be greatly reduced. The results

• blue line, which has two sharp peaks at 430 nm and 530 nm and a wide peak at 600–750 nm, indicates the beginning of 1CS state formation. Then, within 9.67 ps, there is a vibrational relaxation of the charge separated (CS) state (red line in Figure 7d). Later in about 4.53 ns, the triplet features of

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

• work. X-ray crystal structure of CO2 bound to α-CD. TGA curve (blue) and dTGA curve (red) for CO2-1 crystals. Two lumps are seen with the former predominantly being CO2 and the second pre-dominantly water. Cell used to measure vis spectra under pressure (left), structure of 7 (middle) and spectrum of 7

• (40 μM) and 1 (2 mM) in citrate phospate buffer pH 3 (right) from 350–400 nm with 0 (blue), 2 (red), 4 (green), 6 (orange) and 8 (grey) bar of CO2. Binding of CO2 to 1 as a function of pressure. The results of crystallization of α-cyclodextrin from water in an atmosphere of CO2 carried out in a

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• protein RS02200: FAAL: fatty acyl-AMP ligase; ACP: acyl carrier protein; KS: β-ketoacyl synthase; AT: acyltransferase; KR: ketoreductase; C: condensation; A: adenylation; MT: methyltransferase; PCP: peptidyl carrier protein. A discrete enzyme, the thiazolinyl imide reductase RS02195 (Red), catalyzes the

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• the two cyclization modes, the reaction of 4e was monitored by 1H NMR in 5 min intervals (Figure 1). In Figure 1, the red triangles are the total yields of furans 8e and 11e. The yields of cyclopropane 1e and furans 8e and 11e increased with increasing reaction time, without disturbing the shape of

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

• -crystal X-ray structure of rotaxane 1a (R1 = Me, R2 = R3 = H) showing two interlocked molecules of the crystalline array [44]. Colour key of the solid structure: light blue = carbon atoms; purple = nitrogen atoms; red = oxygen atoms; and orange = iron atoms. Hydrogen atoms are omitted for clarity. (a

• the solid structure of UMUMOF-(E)-3 showing a rhombohedral metallogrid; and (c) cartoon representation of the operation mode of UMUMOF-(E)-3 as a molecular nanodispenser [62]. Colour key of the solid structure: light blue = carbon atoms; purple = nitrogen atoms; red = oxygen atoms; and grey = copper

• array [63]. Colour key of the solid structure: light blue = carbon atoms; purple = nitrogen atoms; red = oxygen atoms; and magenta = uranium atoms. Acknowledgements All figures included in this article are original and have been redrawn based on the content of the referenced research articles by using

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• revealed that this reaction was almost a zero-order reaction as shown by the red line in Figure 2, which did not depend on the concentration of 1a (Figure 2). As shown in entries 3 vs 4 in Table 2, the rate-determining step is considered to be the catalytic cycle A in Scheme 1, which is consistent with the

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• HPLC. Due to the large conjugated structure, NG 110 exhibited a significantly red-shifted emission in the near-infrared (NIR) region. Furthermore, the structure extension causes significant improvements both in the fluorescence quantum yield and CPL properties. The dissymmetry factors glum of (P)- and

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

• nitro group. There are two types of independent non-equivalent dications, marked in blue and green, and two types of BF4− anions, marked in red and yellow, in the crystal structure of salt 11c (Figure S68 in Supporting Information File 1). Monomer fragments in both are identical (Table 2, Figure 5). The

• -trifluoromethylphenyl rings. By the way, the qr parameters calculated for two independent molecules of 11c were 0.008 and 0.009, which is slightly less than in the case of compounds 5. As for the crystal packing of 11c, BF4− anions of two types (“red” and “yellow”) interact with cations in different ways. The “red

• yellow, 5d (R = CN) is orange, and 5e (R = NO2) is a crimson crystalline substance. As can be seen from Table 3, compound 5b with electron-releasing methoxy groups shows the smallest λmax value, while the absorption maximum of the nitro derivative 5e is the most red-shifted in the series. There is a