Organic electron transport materials

• Joseph Cameron and
• Peter J. Skabara

Beilstein J. Org. Chem. 2024, 20, 672–674, doi:10.3762/bjoc.20.60

• react with acceptors to produce reducing radical species, capable of reducing organic electron transport materials with a low electron affinity [4][5]. It is not only in modifying the molecular structure to improve the electron accepting ability that there is innovation in new organic electron transport

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

• 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

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

• ]thiadiazolo[3,4-g]quinoxaline in its polymer backbone. The transition from a closed-shell aromatic state to a high-spin quinoidal form resulted in favorable changes in the bandgap, electron affinity, and delocalization of spin density. These changes have the potential to improve charge transport and efficient

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

• the D–A–D structure to further reduce the bandgap, thereby red-shifting the absorption and emission wavelengths. In addition, the strong electron affinity of Nz and the electron-donating and hole-transporting ability of carbazole would build in the good ability to transport electrons and holes

• material with the mobility of electrons somewhat greater than that of holes. The pronounced ability of TPECNz to transport electrons could be accredited to a strong-electron affinity of the Nz core, while its ability to transport holes could be derived from the attached carbazole moieties. To evaluate the

• electron affinity of Nz unit, and electron donating and hole-transporting properties of carbazole nurtured the molecule to exhibit an intense deep-red emission with decent PL quantum yield, superior thermal property, and ambipolar charge-carrier-transporting property with a good balance of mobility of

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

• strength due to its higher electron affinity. While this trend was also true with the poly-substituted ylide I-14, the electron-rich arene significantly offset the electropositivity on the iodine, resulting in two σ-holes of diminished strength (0.040 e, 0.031 e). Despite the historically limited

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

• recombination dynamics is primarily related to the electronic properties of the conjugates, such as electron affinity, orbital energies, and excited state energies. In another report, Nikolaou et al. [51] described the synthesis of two novel porphyrin dyads 107b and 108b containing terminal carboxylic acid

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• wavelength is at 701 nm, which corresponds to 1.77 eV. An ionisation energy of 5.5 eV and an electron affinity of 3.3 eV were estimated by cyclic voltammetry measurements. We have applied this new molecule in organic field effect transistors. The material exhibited a p-type mobility up to 1.33 × 10−4 cm2 V−1

• Cyclic voltammetry (CV) was used to estimate the ionisation energy (IE) and the electron affinity (EA) of the title compound (Figure 9) [63]. CV was measured in a 10−4 M CH2Cl2 solution with 0.1 M tetra-n-butylammonium hexafluorophosphate (TBAPF6) added as electrolyte. A platinum disk electrode, a Pt

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

• pyridine electron acceptor with high electron affinity. Later in 2020, Wang’s group employed this host material, respectively mixed with two Lewis acids, namely BCF and B(C6H5)3, to construct highly luminescent exciplexes [29]. The PL spectra of the new emission system showed an obvious red-shift through

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• such as triazine, diazines or aromatics containing cyano and sulfone groups are popular acceptor units for the construction of highly efficient TADF emitters [8][9][10][11]. Pyrimidine (1,3-diazine) owing to its aromaticity, significant π-deficiency, strong electron affinity, high luminous efficiency

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

• group. Consequently, they influence the electronic situation of the prepared tetrahydroacridines and are expected to change their structural proprieties. Hence, some structural parameters including gap (Eg), ionization potential (IP), electron affinity (EA) and dipole moments (µ) were deduced on the

• polarity difference. In fact, derivative 4f shows the highest dipole moment of 4.276 D as compared to 4a (0.698 D). As shown in Table 5, the ionization potential (IP) and electron affinity (EA) of tetrahydroacridines are almost identical. In addition, EHOMO and ELUMO do not change notably and the

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• polymers in which aromatic fragments are linked by a single bond, a number of homopolymers 53 was obtained by the aldol polycondensation reaction [97]. These compounds have rigid and almost planar structures with a wide absorption range, high electron affinity, good solubility, and ambient stability

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• ]. [7]Helicenes of this group demonstrated a relatively high electron affinity and could be good candidates for electron-injection hole-blocking layers [39]. Donor–acceptor hybride [6]helicenes, consisting of carbazole and phenanthridine cores, are interesting as hole-transporting compounds [47]. At

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• summarized in Table 1. The ionization potential (IPCV) and electron affinity (EACV) values were estimated accordingly from the oxidation and reduction onset potentials against ferrocene (Eox/Ered,onset vs Fc). The IPCV values demonstrated the similar and collaborative electron-donating effect of the

• carbazole, phenothiazine, and 2,7-di-tert-butyl-9,9-dimethylacridine donor moieties on the electron-releasing energy. The phenothiazine-substituted quinazoline compound 3 required the lowest energy for electron release compared to the other compounds studied. The electron affinity values were comparable as

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

• found in the range of 5.11–5.18 eV. The electron affinity values were deduced from the IPcv and energy gap (Egopt) obtained from the onsets of the UV–vis absorption spectra. The ionization potentials IPPES of the solid films of derivatives 3–6 were estimated by photoelectron emission spectrometry (PES

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• , with only slight contributions from the TPA units (ii) The position of the methyl groups has by far a larger impact on the electron affinity of the molecules, which is substantially increased when going from 2 to 1, and from 4 to 3. This is clearly not a direct electronic effect but rather results from

Three-component coupling of aryl iodides, allenes, and aldehydes catalyzed by a Co/Cr-hybrid catalyst

• Kimihiro Komeyama,
• Shunsuke Sakiyama,
• Kento Iwashita,
• Itaru Osaka and
• Ken Takaki

Beilstein J. Org. Chem. 2018, 14, 1413–1420, doi:10.3762/bjoc.14.118

• [10][11][12]. We have recently demonstrated the high π-electron affinity of an organocobalt species that enabled a variety of alkyne functionalization reactions to proceed via carbocobaltation (Scheme 3) [13][14][15]. Furthermore, a combination of the cobalt and chromium catalyst could be applied to

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

• Lin Gan,
• Xianglong Li,
• Xinyi Cai,
• Kunkun Liu,
• Wei Li and
• Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

• fabrication of OLEDs. In order to characterize their electrochemical properties, cyclic voltammetry (CV) measurements were conducted to measure their oxidation potentials (Eox) and reduction potentials (Ered). Ionization potential (IP) and electron affinity (EA), which approximate to their HOMO and LUMO

One-pot three-component route for the synthesis of S-trifluoromethyl dithiocarbamates using Togni’s reagent

• Azim Ziyaei Halimehjani,
• Martin Dračínský and
• Petr Beier

Beilstein J. Org. Chem. 2017, 13, 2502–2508, doi:10.3762/bjoc.13.247

• moiety of piperidine, pyrrolidine and diethylamine adducts, respectively. The results revealed that the rotational barrier in fluorinated dithiocarbamates is slightly higher than in the nonfluorinated analogue [35][38][39]. This may be attributed to a higher electron affinity of the trifluoromethyl group

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• analogue P2, the LUMO energy decreased by 0.10 eV compared to P1 (indicating an increased electron affinity upon fluorination) and the corresponding HOMO level stabilized by 0.24 eV. Hence, both molecular energy levels could be tailored by the introduction of fluorine. In the case of P3, the HOMO level

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• bond can be strengthened. The electron affinity for C6F6 is much larger than that for benzene [24]. Consequently interaction of the filled b2 fragment orbital with the LUMO of C6F6 is expected to be larger and the binding energy larger than that for benzene. The M and L that we shall use in this work

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• macromolecular chains and the macrocycles, 3, 3·TM-βCD and 3·TM-γCD were electrochemically investigated by cyclic voltammetry (CV), Figure 4 and the results are summarized in Table 2. The Ep,onset and En,onset values allow the estimation of the ionization potential (IP), electron affinity (EA) and energy band

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• . Synthetic route to the target exTTF-based molecular wire 5. Kohn–Sham HOMO and LUMO, ionization potential (IP), electron affinity (EA) and image charge correction for occupied Δocc and Δvirt unoccupied orbitals. All quantities are in eV. Supporting Information Supporting Information File 150: Detailed

• , while the LUMO and all other unoccupied orbital levels were shifted by Σvirt=−EA − εL +Δvirt. Here, Δocc (Δvirt) is the image charge correction for the occupied (unoccupied) states, εH (εL) is the Kohn–Sham energy of the gas phase HOMO (LUMO), and IP(EA) is the gas phase ionization potential (electron

• affinity). All quantities are reported in Table 1 for both binding geometries. The alignment of the Breit–Wigner resonances related to both the HOMO and LUMO (at approximately −1 and 2.7 eV from the Fermi level, respectively) do not show a strong dependence on the binding geometry (Figure 9). The electron

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• charge at the heterocyclic nitrogen N-5, and strong electron affinity and polar groups at the 3 and/or 8 position of the phenanthridine can efficiently and predictably regulate the spectroscopic response (UV–vis and fluorescence) of the chromophore [48]. The understanding of the intercalation process

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• is consistent with DFT calculations (vide infra), showing in this case localisation of the LUMO exclusively on the BODIPY core. The positive inductive effect of four methyl groups attached to the core can also contribute to a decrease in the electron affinity of the BODIPY unit in this case. The HOMO

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• . This modest alteration imparts an inherent propensity of the IF scaffold to be electron accepting [10][11]. A simple explanation for the high electron affinity of the IF is that to make all five rings formally aromatic two electrons must be added to the system, effectively creating two cyclopentadiene

• anions [12]. The result of the IFs high electron affinity is nearly balanced ambipolar charge transport in OFETs [11][13]. The synthetic precursors to 1, the indeno[1,2-b]fluorene-6,12-diones (IF-diones, 2, Figure 1) have also been explored as an active layer in OFETs. The first reported IF-dione OFET