Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• and co-workers reported a series of superhelicenes that combine helical and planar π-systems. However, the structural characterization of compound 1 (Table 1) was impeded by its inherent instability, limiting further analysis [14]. In 2024, Liu’s group developed a series of nonalternant nanographenes

• and molecular core design in optimizing the chiroptical and emissive properties of heteroatom-rich nanographenes, advancing their potential in next-generation optoelectronic and chiral photonic devices. B,N-containing helicenes Enhancing charge transfer between electron-donating and electron-accepting

• modulation in tuning the electronic and photophysical properties of chiral nanographenes. These studies exemplify how strategic structural and electronic design – through π-extension, end-group heteroatom engineering, and atom-specific substitutions – enables precise tuning of chiroptical and photophysical

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• Bartlomiej Pigulski Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland 10.3762/bjoc.21.99 Abstract In recent years, significant progress has been made in the synthesis of various nanographenes incorporating non-benzenoid rings, expanding the scope of molecular

• nanographenes, with a particular focus on the synthetic strategies. Additionally, it explores selected aspects of aromaticity and spectroscopic properties. Keywords: azulene; nanographenes; non-alternant; non-benzenoid; polycyclic aromatic hydrocarbons; Introduction The discovery of graphene and fullerenes

• crucial for fine-tuning their properties. An alternative is the bottom-up approach where various nanographenes are synthesized form smaller building blocks via classical organic synthesis. This strategy enables precise control over the structure and topology, leading to the development of a vast array of

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• irradiation. The authors claim that toluene acts as a photosensitizer since cyclohexane, which has similar solubilizing power, did not serve well as a LAG agent. The authors demonstrated that nanographenes could be obtained via cyclodehydrochlorination of 10.3 under photomechanochemical conditions as well

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• -doped triphenylene derivative 22. In the same year, An et al. reported their investigations regarding chalcogen-doped hexa-peri-benzocoronene (HBC) derivatives and their controllable conversion into hydrocarbon nanographenes by ring contraction of the heteropine moiety [65]. The authors first tackled

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

• Ranran Li Di Wang Shengtao Li Peng An School of Chemical Science and Technology, Yunnan University, Kunming 650500, P. R. China 10.3762/bjoc.19.54 Abstract The past decade witnessed remarkable success in synthetic molecular nanographenes. Encouraged by the widespread application of chiral

• nanomaterials, the design, and construction of chiral nanographenes is a hot topic recently. As a classic nanographene unit, hexa-peri-hexabenzocoronene generally serves as the building block for nanographene synthesis. This review summarizes the representative examples of hexa-peri-hexabenzocoronene-based

• chiral nanographenes. Keywords: chiral nanographene; helicene; racemization barrier; Scholl reaction; single-crystal X-ray diffractometry; Introduction Graphene, an allotrope of carbon, has captured widespread attention since it was first experimentally demonstrated as a monolayer of carbon atoms [1

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• introduced by Hatakeyama and co-workers, are typically p- and n-doped nanographenes [25][26]. OLEDs using MR-TADF emitters can simultaneously achieve narrowband emission and very high EQEmax. Inspired by our recent work on neutral MR-TADF emitters for OLEDs [27][28], we designed two charged analogues of

Bipyrrole boomerangs via Pd-mediated tandem cyclization–oxygenation. Controlling reaction selectivity and electronic properties

• Liliia Moshniaha,
• Marika Żyła-Karwowska,
• Joanna Cybińska,
• Piotr J. Chmielewski,
• Ludovic Favereau and
• Marcin Stępień

Beilstein J. Org. Chem. 2020, 16, 895–903, doi:10.3762/bjoc.16.81

• measurements show that helicene-like boomerangs may be usable as circularly polarized luminescent materials. Keywords: donor–acceptor systems; double C–H bond activation; helicenes; pyrroles; Introduction Nanographenes and other polycyclic aromatics as well as their heterocyclic analogues are typically

Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• nanopores from the gas phase [15], the intercalation of organic molecules into nanopores is rather difficult to tailor from scratch, however, with prominent examples [16][17]. Likewise, larger polycyclic aromatic hydrocarbons (PAHs) and nanographenes form robust adsorbate films in a certain size range, and

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• ; heteroacene; selenophene; Introduction In recent years, great interest has been devoted to the development of new π-conjugated polycyclic molecules, in particular to polycyclic aromatic hydrocarbons (PAH) such as acenes [1], phenacenes [2], or nanographenes [3]. Corresponding heteroacenes incorporating