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

• devices is discussed in detail. Additionally, their significance as thermally activated delayed fluorescence emitters and chromophores for OLEDs, sensors and electrochromic devices is explored. The review emphasizes the remarkable characteristics and versatility of quinoxaline derivatives in electron

• chromophores in the development of organic light-emitting diodes (OLEDs), sensors, and electrochromic devices [8][13][14]. In this review, we have comprehensively examined the recent advancements of Qx-derived ETMs in various applications within the organic semiconductor device field over the past five to six

• electronic characteristics. To enhance their performance in sensors and electrochromic devices, researchers have concentrated on manipulating their electron transport properties. By tailoring the strength of electron acceptors, fine-tuning the electronic nature of functional groups, incorporating additional

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 possible future directions. Keywords: crown ethers; porphyrinoids; self-assembly; sensors; supramolecular chemistry; Introduction Many areas of modern supramolecular chemistry, organic, inorganic, materials and coordination chemistry, are based upon macrocyclic compounds of specifically-designed

• porphyrins as multitopic receptors, sensors, and supramolecular hosts, with applications in ion transport, catalysis, and polymeric materials [22][40][41][42][43][44][45]. In 1984 Lehn, Sessler and co-workers developed double-side-strapped crowned porphyrins, which served as tritopic and tetratopic receptors

• ether systems, where the catechol unit of the crown ether was fused to two β-pyrrolic positions of the porphyrin periphery. The systems presented intriguing intramolecular electron-transfer properties. Additionally, they were investigated as fluorescent sensors for various organic and metal cations [51

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

• fluorescence [1][2][3]. Organic TADF emitters have gained substantial attention in recent years for their prospective application in organic light-emitting diodes (OLEDs), photocatalysis, bioimaging, and sensors [4][5][6]. The ability to harvest both singlet and triplet excitons enable organic TADF emitters to

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

• well as optical properties. Moreover, the versatility of coumarin hybrids finds numerous applications including fluorescent brightening agents [16], optical sensors [17], organic light emitting diodes [18][19], light harvesting materials [20] and fluorescent probes in biological imaging [21]. Therefore

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• substances such as pharmaceuticals or fragrances is exploited since it is cheap, harmless and biodegradable [4]. It is also a useful building block for sensors and/or capture devices, advanced materials, and even artificial enzymes. Most such uses require that compound 1 can be chemically modified so that

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• Tripodal molecules are widely used as chelating ligands for transition metal catalysis [1][2][3], sensors for ions and small molecules [4][5], reagents for surface grafting [6], building blocks for the construction of supramolecular structures [7], polycyclic cage molecules [8], and porous materials [9

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• detecting organic acid vapor at ambient conditions is challenging for solid-state detectors. Therefore, developing a solid-state emitter with reversible switching of the optical properties by external stimuli, such as acid and base vapors, is important. As per the recent literature, such sensors are being

• disruption of the molecular conjugation or ICT interactions upon protonation or deprotonation would lead to switching of the optical properties. While there are many reports on acid–based sensors, TADF emitter-based sensors are rare in the literature. In this context, we chose the D–A molecular design to

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

• ][16][17][18][19][20][21][22], as well as fluorescent probes [23][24][25][26][27][28] for bioimaging and fluorescent sensors for specific target species [29][30][31][32]. Among many kinds of organic fluorescent dyes, much efforts have been made on the development of donor–π–acceptor (D–π–A)-type

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• have been reported [7][8][9][10]. Because the aggregated state of AIEE-based compounds is affected by the external environment, these compounds have found use in clinical applications as chemical sensors or fluorescent probes [7][8][9][10]. Pyridine is a nitrogen-containing heterocyclic compound found

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

• Anna V. Korotina,
• Svetlana G. Tolshchina,
• Rashida I. Ishmetova,
• Natalya P. Evstigneeva,
• Natalya A. Gerasimova,
• Natalya V. Zilberberg,
• Nikolay V. Kungurov,
• Gennady L. Rusinov,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2022, 18, 243–250, doi:10.3762/bjoc.18.29

• as high-energy materials [23][24][25], molecules with promising photophysical, electrochemical and coordination properties for use in sensors, OLEDs, semiconductor materials, etc. [26][27][28]. The most important biomedical application of 1,2,4,5-tetrazines are bioorthogonal reactions that allow

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• , pharmaceutical, and biological sciences. A lot of the literature in this area is quite old. Perhaps there are also opportunities in this area to apply modern chemistry methodology, and also in the development of more sophisticated sensors and dyes. Naphthoquinones are commonly used in organic synthesis. Some

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• cell proliferation and waste exchange, e.g., in a scaffold for tissue engineering applications [3]. Novel biomedical and biotechnical applications of cryogels can also be found in controlled drug delivery, carriers for cell immobilization, sensors, bioseparation, purification, and wound dressing [4][5

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

• , have been intensively studied in solution. For the application of such polymers in novel sensors, drug delivery systems or as multifunctional coatings, they typically have to be transferred into specific arrangements, such as micelles, polymer films or grafted nanoparticles. However, it turns out that

• including biomedicine [29][30], drug delivery [12][31], tissue engineering [32][33], analytic application [18], environmental applications [34][35], sensors [36][37][38], actuators [37][38][39] and other applications [5]. For many of these purposes, it is essential to tether such polymers to interfaces or

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

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

• of functional materials are analyzed and summarized. These bisheterocycles can be used in the creation of organic solar cells, sensors, lithium ion batteries as well as in OFET and OLED technologies. The potentials of the use of polymer structures based on isoindigo as photoactive component in the

• towards n-butanol. The lower limit of detection was 100 ppm with a response time of less than 10 s. The ability of polymeric isoindigo derivatives to strongly bind to carbon nanotubes due to π-stacking was used to create sensors for the determination of NO2 in the gaseous state (see polymer 61) and

• polymers for OFETs. Isoindigoid homopolymers with differing rigidity. Isoindigo-based materials with extended π-conjugation. Poly(isoindigothiophene) compounds as sensors for ammonia. Sensor devices based on poly(isoindigoaryl) compounds. Isoindigo polymers for miscellaneous applications. Mono-, rod-like

Design, synthesis and photophysical properties of novel star-shaped truxene-based heterocycles utilizing ring-closing metathesis, Clauson–Kaas, Van Leusen and Ullmann-type reactions as key tools

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2021, 17, 1374–1384, doi:10.3762/bjoc.17.96

• macrocycles [31][32]. Moreover, polypyrrolic systems are of extensive interest in numerous areas namely optics, medicine, and supramolecular chemistry in addition to the materials sciences and technology. Fascinatingly, in luminescence as well as fluorescence-based sensors, pyrrole derivatives play a vital

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

• monitoring features such as pressure sensors that can both detect, assess, and if necessary, invoke emergency venting or diversion of material to auxiliary depressurisation stages, often without needing a full reactor shut down. There are numerous examples within the literature in which a flow synthesis has

Beyond ribose and phosphate: Selected nucleic acid modifications for structure–function investigations and therapeutic applications

• Christopher Liczner,
• Kieran Duke,
• Gabrielle Juneau,
• Martin Egli and
• Christopher J. Wilds

Beilstein J. Org. Chem. 2021, 17, 908–931, doi:10.3762/bjoc.17.76

1,2,3-Triazoles as leaving groups: S_NAr reactions of 2,6-bistriazolylpurines with O- and C-nucleophiles

• Dace Cīrule,
• Irina Novosjolova,
• Ērika Bizdēna and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 410–419, doi:10.3762/bjoc.17.37

• ][68][69] and can be used as metal ion sensors [70]. Therefore, it is important to develop novel methods towards this type of derivatives. To date two approaches have been used to obtain 6-substituted 2-triazolylpurine derivatives (Scheme 1). According to the pathway A, firstly a selected substituent

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• ; multiswitchable; photoacid; polyelectrolyte; Introduction Supramolecular nanoscale assemblies responding to multiple stimuli are highly desirable in various fields including transport systems, sensors, and optoelectronic applications [1][2][3][4][5][6][7][8]. Self-assembly into supramolecular structures and

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

• [31], chemical sensors [32], DNA-intercalators [33][34] etc. Besides typical carbohelicenes, heterohelicenes, incorporating one or more heteroaromatic units in the skeleton, have also gained increasing attention [1][2][3][4][5][6][7][8][9][10][11]. The presence of heteroatoms (S, N, O, P) in the fused

Chiral anion recognition using calix[4]arene-based ureido receptors in a 1,3-alternate conformation

• Tereza Horáčková,
• Jan Budka,
• Vaclav Eigner,
• Wen-Sheng Chung,
• Petra Cuřínová and
• Pavel Lhoták

Beilstein J. Org. Chem. 2020, 16, 2999–3007, doi:10.3762/bjoc.16.249

• have gradually been revealed and are well recognised to date. Consequently, given the importance of anions in many areas of everyday life, including, e.g., biology, medicine, environmental pollution issues, or industrial processes, the design and development of novel artificial receptors/sensors for

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• fluorescence techniques have attracted immense interest. Synthetic peptide-based fluorescent probes are advantageous over protein-based sensors, since they are synthetically accessible, more stable, and can be easily modified in a site-specific manner for selective biological applications. Peptide receptors

• for biomolecule detection [27][28]. Being intrinsically modular, peptide scaffolds also allow the attachment of multiple fluorophores simultaneously [29]. It provides the opportunity of developing ratiometric fluorescent sensors from the interaction between multiple fluorophores (Figure 1B

• arms attached through their C-terminus to a central lysine. Two heparin sensors 10 and 11 are developed by attaching the N-terminus of the peptide beacon with pyrenes and fluorescence resonance energy transfer (FRET) pair (naphthalene and dansyl), respectively for ratiometric detection of heparin

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

• applications or in the case of NMe2, as sensors of dielectric constants or water content. Molecular structure in the crystal of Me as obtained by X-ray diffractometric analysis. Thermal displacement ellipsoids are shown with 50% probability. Color code: black = carbon, grey = hydrogen and blue = nitrogen. A