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Synthesis,Characterization, and Properties of [4]Cyclo‐2,7‐pyrenylene: Effects of Cyclic Structure on the Electronic Properties of Pyrene Oligomers 下载免费PDF全文
Takahiro Iwamoto Dr. Eiichi Kayahara Dr. Nobuhiro Yasuda Prof. Dr. Toshiyasu Suzuki Prof. Dr. Shigeru Yamago 《Angewandte Chemie (International ed. in English)》2014,53(25):6430-6434
A cyclic tetramer of pyrene, [4]cyclo‐2,7‐pyrenylene ([4]CPY), was synthesized from pyrene in six steps and 18 % overall yield by the platinum‐mediated assembly of pyrene units and subsequent reductive elimination of platinum. The structures of the two key intermediates were unambiguously determined by X‐ray crystallographic analysis. DFT calculations showed that the topology of the frontier orbitals in [4]CPY was essentially the same as those in [8]cycloparaphenylene ([8]CPP), and that all the pyrene units were fully conjugated. The electrochemical analyses proved the electronic properties of [4]CPY to be similar to those of [8]CPP. The results are in sharp contrast to those obtained for the corresponding linear oligomers of pyrene in which each pyrene unit was electronically isolated. The results clearly show a novel effect of the cyclic structure on cyclic π‐conjugated molecules. 相似文献
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Dominik Lorbach Dr. Ashok Keerthi Dr. Teresa Marina Figueira‐Duarte Prof. Dr. Martin Baumgarten Dr. Manfred Wagner Prof. Dr. Klaus Müllen 《Angewandte Chemie (International ed. in English)》2016,55(1):418-421
First synthesis of the macrocycle cyclohexa(1,3‐pyrenylene) is achieved in six steps starting with pyrene, leading to a non‐aggregating highly twisted blue‐light‐emitting material. The cyclodehydrogenation of the macrocycle offers a promising synthesis route to holey‐nanographene. 相似文献
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Hideto Ito Yukari Mitamura Yasutomo Segawa Kenichiro Itami 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(1):161-165
The synthesis of cyclo‐1,4‐phenylene‐2′,5′‐thienylenes (CPTs) as the first example of a thiophene‐based, radially π‐conjugated system is described. X‐ray crystal structures, UV‐vis absorption and emission spectra, and theoretical studies revealed the unique structural and photophysical properties of CPTs. With all of these unique structural and photophysical properties, the radially π‐conjugated CPTs are expected to open a door for the discovery and development of new functional organic materials. 相似文献
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《化学:亚洲杂志》2017,12(16):2093-2097
Five congeners of [n ]cyclo‐3,6‐phenanthrenylene with 3, 4, 5, 7, and 8 panels were obtained from one‐pot macrocyclization of dibromophenanthrene, and their crystal structures with diverse molecular shapes were revealed by X‐ray crystallography. The compounds, except the four‐panel congener, were highly fluorescent in solution, with quantum yields up to 85 %. The least fluorescent four‐panel congener showed the smallest change in its absorption spectrum from that of monomeric phenanthrene, which provided an interesting structure–activity relationship for fluorescent macrocycles to guide future studies. 相似文献
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A set of monodisperse 2,7‐linked carbazole oligomers (3‐mer, 5‐mer, 7‐mer, and 9‐mer) was synthesized, and their photophysical, electrochemical, and thermal properties were investigated. In solutions, these oligomers exhibited bright blue emission with almost quantitative fluorescence quantum yield. The emission spectra of these oligomers in films are quite different. 3‐Mer and 5‐mer exhibited featureless emission spectra, whereas 7‐mer and 9‐mer showed well‐resolved emission spectra. 相似文献
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Chengyuan Wang Jing Zhang Guankui Long Naoki Aratani Hiroko Yamada Yang Zhao Qichun Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(21):6390-6394
Increasing the length of N‐heteroacenes or their analogues is highly desirable because such materials could have great potential applications in organic electronics. In this report, the large π‐conjugated N‐heteroquinone 6,10,17,21‐tetra‐((triisopropylsilyl)ethynyl)‐5,7,9,11,16,18,20,22‐octaazanonacene‐8,19‐dione (OANQ) has been synthesized and characterized. The as‐prepared OANQ shows high stability under ambient conditions and has a particularly low LUMO level, which leads to it being a promising candidate for air‐stable n‐type field‐effect transistors (FETs). In fact, FET devices based on OANQ single crystals have been fabricated and an electron mobility of up to 0.2 cm2 V−1 s−1 under ambient conditions is reported. More importantly, no obvious degradation was observed even after one month. Theoretical calculations based on the single crystal are consistent with the measured mobility. 相似文献
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Layered Black Phosphorus: Strongly Anisotropic Magnetic,Electronic, and Electron‐Transfer Properties
Zdenk Sofer David Sedmidubský tpn Huber Jan Luxa Daniel Boua Chris Boothroyd Martin Pumera 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(10):3443-3447
Layered elemental materials, such as black phosphorus, exhibit unique properties originating from their highly anisotropic layered structure. The results presented herein demonstrate an anomalous anisotropy for the electrical, magnetic, and electrochemical properties of black phosphorus. It is shown that heterogeneous electron transfer from black phosphorus to outer‐ and inner‐sphere molecular probes is highly anisotropic. The electron‐transfer rates differ at the basal and edge planes. These unusual properties were interpreted by means of calculations, manifesting the metallic character of the edge planes as compared to the semiconducting properties of the basal plane. This indicates that black phosphorus belongs to a group of materials known as topological insulators. Consequently, these effects render the magnetic properties highly anisotropic, as both diamagnetic and paramagnetic behavior can be observed depending on the orientation in the magnetic field. 相似文献
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Tomohito Morosaki Tsubasa Suzuki Wei‐Wei Wang Shigeru Nagase Takayoshi Fujii 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(36):9723-9725
Electronic effects on the central carbon atom of carbone, generated by the replacement of the SIV ligand of carbodisulfane (CDS) with other chalcogen ligands (Ph2E, E=S or Se), were investigated. The carbones Ph2E→C←SPh2(NMe) [E=S( 1 ) or Se( 2 )] were synthesized from the corresponding salts, and their molecular structures and electronic properties were characterized. The carbone 2 is the first carbone containing selenium as the coordinated atom. DFT calculations revealed the electronic structures of 1 and 2 , which have two lone pairs of electrons at the carbon center. The trend in HOMO energy levels, estimated by cyclic voltammetry measurements, for the carbones and CDS follows the order of 2 > 1 >CDS. Analysis of a doubly protonated dication and trication complex revealed that the central carbon atom of 2 behaves as a four‐electron donor. 相似文献
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Fabien Lucas Dr. Lambert Sicard Dr. Olivier Jeannin Dr. Joëlle Rault-Berthelot Dr. Emmanuel Jacques Dr. Cassandre Quinton Dr. Cyril Poriel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(32):7740-7748
Nanorings, which are macrocycles possessing radially directed π-orbitals have shown fantastic development in the last ten years. Unravelling their unusual electronic properties has been one of the driving forces of this research field. However, and despite promising properties, their incorporation in organic electronic devices remains very scarce. In this work, we aim to contribute to bridge the gap between organic electronics and nanorings by reporting the synthesis, the structural and electronic properties and the incorporation in an organic field-effect transistor (OFET) of a cyclic tetracarbazole, namely [4]cyclo-N-ethyl-2,7-carbazole ( [4]C-Et-Cbz ). The structural, photophysical and electrochemical properties have been compared to those of structurally related analogues [4]cyclo-9,9-diethyl-2,7-fluorene [4]C-diEt-F (with carbon bridges) and [8]-cycloparaphenylene [8]CPP (without any bridge) in order to shed light on the impact of the bridging in nanorings. This work shows that nanorings can be used as an active layer in an OFET and provides a first benchmark in term of OFET characteristics for this type of molecules. 相似文献
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Ligand‐Controlled Synthesis of [3]‐ and [4]Cyclo‐9,9‐dimethyl‐2,7‐fluorenes through Triangle‐ and Square‐Shaped Platinum Intermediates 下载免费PDF全文
Dr. Eiichi Kayahara Rui Qu Mitsuru Kojima Dr. Takahiro Iwamoto Prof. Dr. Toshiyasu Suzuki Prof. Dr. Shigeru Yamago 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):18939-18943
The syntheses of [3]‐ and [4]cyclo‐9,9‐dimethyl‐2,7‐fluorenes ([3] and [4]CFRs), cyclic trimer, and tetramers of 9,9‐dimethyl‐2,7‐fluorene (FR), respectively, were achieved by the platinum‐mediated assembly of FR units and subsequent reductive elimination of platinum. A triangle‐shaped tris‐platinum complex and a square‐shaped tetra‐platinum complex were obtained by changing the platinum ligand. The structure of the triangle complex was unambiguously determined by X‐ray crystallographic analysis. Reductive elimination of each complex gave [3] and [4]CFRs. Two rotamers of [3]CFR were sufficiently stable at room temperature and were separated by chromatography. The physical properties of the CFRs were also investigated theoretically and experimentally. 相似文献
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