排序方式: 共有8条查询结果,搜索用时 0 毫秒
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Dr. Shinobu Arikawa Dr. Akihiro Shimizu Dr. Daisuke Shiomi Prof. Dr. Kazunobu Sato Prof. Dr. Takeji Takui Dr. Hikaru Sotome Prof. Dr. Hiroshi Miyasaka Dr. Masahito Murai Prof. Dr. Shigehiro Yamaguchi Prof. Dr. Ryo Shintani 《Angewandte Chemie (International ed. in English)》2023,62(29):e202302714
A kinetically-stabilized nitrogen-doped triangulene cation derivative has been synthesized and isolated as the stable diradical with a triplet ground state that exhibits near-infrared emission. As was the case for a triangulene derivative we previously synthesized, the triplet ground state with a large singlet-triplet energy gap was experimentally confirmed by magnetic measurements. In contrast to the triangulene derivative, the nitrogen-doped triangulene cation derivative is highly stable even in solution under air and exhibits near-infrared absorption and emission because the alternancy symmetry of triangulene is broken by the nitrogen cation. Breaking the alternancy symmetry of triplet alternant hydrocarbon diradicals by a nitrogen cation would therefore be an effective strategy to create stable diradicals possessing magnetic properties similar to the parent hydrocarbons but with different electrochemical and photophysical properties. 相似文献
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Tong Shen Diego Dijkstra Alex Farrando-Pérez Dr. Pedro G. Boj Dr. José M. Villalvilla Dr. José A. Quintana Dr. Ya Zou Dr. Xudong Hou Dr. Haipeng Wei Dr. Zhentao Li Prof. Zhe Sun Prof. María A. Díaz-García Prof. Jishan Wu 《Angewandte Chemie (International ed. in English)》2023,62(27):e202304197
Large graphene-like molecules with four zigzag edges are ideal gain medium materials for organic near-infrared (NIR) lasers. However, synthesizing them becomes increasingly challenging as the molecular size increases. In this study, we introduce a new intramolecular radical-radical coupling approach and successfully synthesize two fused triangulene dimers ( 1 a / 1 b ) efficiently. X-ray crystallographic analysis of 1 a indicates that there is no intermolecular π-π stacking in the solid state. When the more soluble derivative 1 b is dispersed in polystyrene thin films, amplified spontaneous emission in the NIR region is observed. Using 1 b as the active gain material, we fabricate solution-processed distributed feedback lasers that exhibit a narrow emission linewidth at around 790 nm. The laser devices also exhibit low thresholds with high photostability. Our study provides a new synthetic strategy for extended nanographenes, which have diverse applications in electronics and photonics. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(18):5169-5172
The increasing attention devoted to triangulenes and their heteroatom derivatives inspired us to explore a divergent synthesis of heteroatom‐centered 4,8,12‐triazatriangulenes, which involved the preparation of a nitrogen‐containing macrocyclic precursor and subsequent central heteroatom introduction by electrophilic C−Li and C−H substitution. The boron‐centered triangulene has a planar structure unlike the bowl‐shaped phosphorus‐ and silicon‐centered triangulenes. The described synthetic procedure can be used to fabricate a broad range of attractive functional materials, for example, for organic light‐emitting diodes, based on heteroatom‐centered triangulenes. 相似文献
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Jie Su Mykola Telychko Shaotang Song Jiong Lu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(20):7730-7740
Triangulene and its higher homologues are a class of zigzag-edged triangular graphene molecules (ZTGMs) with high-spin ground states. These open-shell molecules are predicted to host ferromagnetically coupled edge states with net spin values scaling with molecular size and are therefore considered promising candidates for future molecular spintronics applications. Unfortunately, the synthesis of unsubstituted [n]triangulenes and the direct observation of their edge states have been a long-standing challenge due to a high reactivity towards oxygen. However, recent advances in precursor design enabled the on-surface synthesis and characterization of unsubstituted [3]-, [4]-, and [5]triangulene. In this Minireview, we will highlight key aspects of this rapidly developing field, ranging from the principles of precursor design to synthetic strategies and characterization of a homologous series of triangulene molecules synthesized on-surface. We will also discuss challenges and future directions. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(34):10322-10325
Conjugated radicals are capable of forming π‐stacking “pancake‐bonded” dimers. Members of the family of triangulene hydrocarbons, non‐Kekulé neutral multiradicals, can utilize more than one singly occupied molecular orbital (SOMO) to form multiple pancake‐bonded dimers with formal bond orders of up to five. The resulting dimer binding energies can be quite high and the intermolecular contacts rather small compared to the respective van der Waals values. The preferred configurations are driven by the large stabilization energy of overlapping SOMOs. 相似文献
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Michael J. Bearpark Francois Ogliaro Thom Vreven Martial Boggio-Pasqua Michael J. Frisch Susan M. Larkin Marc Morrison Michael A. Robb 《Journal of photochemistry and photobiology. A, Chemistry》2007,190(2-3):207-227
In this article, we compare and contrast the RASSCF, ONIOM and MMVB electronic structure methods for calculating relaxation paths on potential energy surfaces of the excited states of large molecules, and for locating any resulting conical intersections at which nonadiabatic decay can take place. Each method is treated here as an approximation to CASSCF, which we choose as our reference level of theory, but which becomes prohibitively expensive computationally for large molecules. Both MMVB and ONIOM are hybrid computational methods – combining different levels of theory in an energy plus derivatives calculation at a particular molecular geometry – but they differ fundamentally in that MMVB is a hybrid-atom method, whereas ONIOM is a hybrid-molecule method. We explain this distinction through four representative applications: the photostability of pyracylene (studied with CASSCF, RASSCF, MMVB); large geometry changes in the singlet excited states of triangulene (studied with MMVB); a model for interstitial nickel defects in a synthetic diamond lattice (studied with ONIOM CAS:UFF); and the photochemical [4 + 4] cycloaddition of cyclohexadiene to naphthalene (studied with ONIOM CAS:MMVB). We show that each method is more appropriate for a particular type of photochemical problem. This article is part perspective, part review, and contains new results for three multi-state or photoinduced processes in complex systems. 相似文献
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Dr. Manuel Vilas-Varela Francisco Romero-Lara Alessio Vegliante Dr. Jan Patrick Calupitan Adrián Martínez Lorenz Meyer Unai Uriarte-Amiano Dr. Niklas Friedrich Dr. Dongfei Wang Dr. Fabian Schulz Dr. Natalia E. Koval Dr. María E. Sandoval-Salinas Dr. David Casanova Dr. Martina Corso Prof. Emilio Artacho Prof. Dr. Diego Peña Prof. José Ignacio Pascual 《Angewandte Chemie (International ed. in English)》2023,62(41):e202307884
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