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951.
Chun‐Kai Wang Xiaozhou Che Yuan‐Chih Lo Ya‐Ze Li Yung‐Hao Wang Stephen R. Forrest Shun‐Wei Liu Ken‐Tsung Wong 《化学:亚洲杂志》2020,15(16):2520-2531
Four new donor‐acceptor‐acceptor’ (D‐A‐A’)‐configured donors, CPNT , DCPNT , CPNBT , and DCPNBT equipped with naphtho[1,2‐c:5,6‐c′]bis([1,2,5]‐thiadiazole) (NT) or naphtho[2,3‐c][1,2,5]thiadiazole (NBT) as the central acceptor (A) unit bridging triarylamine donor (D) and cyano or dicyanovinylene acceptor (A’), were synthesized and characterized. All molecules exhibit bathochromic absorption shifts as compared to those of the benzothiadiazole (BT)‐based analogues owing to improved electron‐withdrawing and quinoidal character of NT and NBT cores that lead to stronger intramolecular charge transfer. Favorable energy level alignments with C70, together with the good thermal stability and the antiparallel dimeric packing render CPNT and DCPNT suitable donors for vacuum‐processed organic photovoltaics (OPV)s. OPVs based on DCPNT : C70 active layers displayed the best power conversion efficiency (PCE)=8.3%, along with an open circuit voltage of 0.92 V, a short circuit current of 14.5 mA cm?2 and a fill factor of 62% under 1 sun intensity, simulated AM1.5G illumination. Importantly, continuous light‐soaking with AM 1.5G illumination has verified the durability of the devices based on CPNT :C70 and DCPNT : C70 as the active blends. The devices were examined for their feasibility of indoor light harvesting under 500 lux illumination by a TLD‐840 fluorescent lamp, giving PCE=12.8% and 12.6%, respectively. These results indicate that the NT‐based D‐A‐A’‐type donors CPNT and DCPNT are potential candidates for high‐stability vacuum‐processed OPVs suitable for indoor energy harvesting. 相似文献
952.
Enantioselective Synthesis of [9]‐ and [11]Helicene‐like Molecules: Double Intramolecular [2+2+2] Cycloaddition
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Yuki Kimura Naohiro Fukawa Yuta Miyauchi Prof. Dr. Keiichi Noguchi Prof. Dr. Ken Tanaka 《Angewandte Chemie (International ed. in English)》2014,53(32):8480-8483
The enantioselective synthesis of completely ortho‐fused [9]‐ and [11]helicene‐like molecules has been achieved through a rhodium‐mediated, intramolecular, double [2+2+2] cycloaddition of phenol‐ or 2‐naphthol‐linked hexaynes. Crystal structures and photophysical properties of these [9]‐ and [11]helicene‐like molecules have also been disclosed. 相似文献
953.
Annulation Approach to Doubly Linked (A‐type) Oligocatechins: Syntheses of (+)‐Procyanidin A2 and (+)‐Cinnamtannin B1
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Yuji Ito Prof. Dr. Ken Ohmori Prof. Dr. Keisuke Suzuki 《Angewandte Chemie (International ed. in English)》2014,53(38):10129-10133
The first stereoselective syntheses of doubly linked (A‐type) oligocatechins, (+)‐procyanidin A2 and (+)‐cinnamtannin B1, have been achieved. Ethylenedioxy‐bridged flavans served as excellent platforms, thus allowing annulation with nucleophilic catechin units in a stereoselective manner. An additional key was the new synthetic approach to selectively protected nucleophilic catechin, thus enabling regioselective construction of the key dioxabicyclo skeleton of the A‐type oligocatechins. 相似文献
954.
Supramolecular Engineering of Oligothiophene Nanorods without Insulators: Hierarchical Association of Rosettes and Photovoltaic Properties
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Prof. Dr. Shiki Yagai Mika Suzuki Dr. Xu Lin Marina Gushiken Takuya Noguchi Prof. Dr. Takashi Karatsu Prof. Dr. Akihide Kitamura Prof. Dr. Akinori Saeki Prof. Dr. Shu Seki Dr. Yoshihiro Kikkawa Yuki Tani Prof. Dr. Ken‐ichi Nakayama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16128-16137
Supramolecular rosettes of oligothiophenes that do not bear long aliphatic tails have been designed as semiconducting nanomaterials for solution‐processable bulk heterojunction solar cells. The rosettes consist of six barbiturated thienyl[oligo(hexylthiophene)] units (Bar‐T‐hTn; n=3,4,5) aggregated by multiple hydrogen bonds, which have been directly visualized by scanning tunneling microscopy (STM) at a solid–liquid interface. 1H NMR spectroscopy in [D8]toluene showed that Bar‐T‐hTn exists as a mixture of monomers and small hydrogen‐bonded aggregates. Hierarchical organization of the hydrogen‐bonded aggregates took place through π–π stacking interactions upon casting their toluene solutions, resulting in the growth of highly ordered nanorods whose widths are consistent with the diameters of the rosettes. The nanorods could be generated in the presence of soluble fullerene derivatives via solution casting or the annealing of the resulting thin films. The solar cells fabricated based on these bulk heterojunction films showed power conversion efficiencies of 1–3 %, which are far higher than those of the non‐hydrogen‐bonded reference oligothiophene and the derivative that possesses long aliphatic tails. 相似文献
955.
Multicolour Fluorescent Memory Based on the Interaction of Hydroxy Terphenyls with Fluoride Anions
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Masaaki Akamatsu Dr. Taizo Mori Dr. Ken Okamoto Prof. Dr. Hideki Sakai Prof. Dr. Masahiko Abe Dr. Jonathan P. Hill Prof. Dr. Katsuhiko Ariga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16293-16300
Memory operations based on variation of a molecule’s properties are important because they may lead to device miniaturization to the molecular scale or increasingly complex information processing protocols beyond the binary level. Molecular memory also introduces possibilities related to information‐storage security where chemical information (or reagents) might be used as an encryption key, in this case, acidic/basic reagents. Chemical memory that possesses both volatile and non‐volatile functionality requires reversible conversion between at least two chemically different stable or quasi‐stable states. Here we have developed the phenol–phenoxide equilibrium of phenol fluorophores as a data storage element, which can be used to write or modulate data using chemical reagents. The properties of this system allow data to be stored and erased either in non‐volatile or volatile modes. We also demonstrate non‐binary switching of states made possible by preparation of a composite containing the molecular memory elements. 相似文献
956.
957.
Dramatic Mechanistic Change in Acid‐Catalyzed Arylation of Azafulleroids Depending on their Ambident N/C Basicity: Formation of Cyclopentene Centered Pentakisadduct
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Dr. Naohiko Ikuma Yuta Doi Koichi Fujioka Tsubasa Mikie Dr. Ken Kokubo Prof. Dr. Takumi Oshima 《化学:亚洲杂志》2014,9(11):3084-3088
Azafulleroid, amino‐bridged [5,6]‐open fullerene, has the ambident N/C basicity of the incorporated enamine moiety. Acid‐catalyzed arylation of N‐substituted azafulleroids proceeded via two types of initial N/C protonation to perform monoarylation or 1,4‐bisarylation for the N‐alkyl substituents and shuttlecock‐type pentakisarylation for the N‐phenyl substituent. The dramatic product change was explained by considering the possible mechanism as well as the DFT computational results. 相似文献
958.
Tomomi Kawasaki Yoshinori Nonaka Ken Matsumura Miyuki Monai Masanori Sakamoto 《合成通讯》2013,43(18):3251-3261
An efficient method for synthesis of 2-methoxy-l,2-dihydro-3H-indol-3-ones using two successive oxidations of indoles is described. 相似文献
959.
Ken Sasaki 《Zeitschrift fur Physik C Particles and Fields》1986,32(1):149-152
The renormalization group equations for the parametrization-convention independent quadratic parameters |V ij |2 of the KM matrix are derived. Numerical analysis of these equations shows that the heavy quark family (t, b) tends to mix with the lighter families (c, s) and (u, d) with increasing energy, although the variation is very much slow. The CP-nonconservation effects are shown to get larger with energy. 相似文献
960.
Guantao Chen Hikoe Enomoto Ken‐ichi Kawarabayashi Katsuhiro Ota Dingjun Lou Akira Saito 《Journal of Graph Theory》2004,46(3):145-166
A minimum degree condition is given for a bipartite graph to contain a 2‐factor each component of which contains a previously specified vertex. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 145–166, 2004 相似文献