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91.
Shotaro Hayashi Fumitaka Ishiwari Takanori Fukushima Shohei Mikage Yutaka Imamura Motomichi Tashiro Michio Katouda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16329-16335
Elastic organic crystals have attracted considerable attention as next-generation flexible smart materials. However, the detailed information on both molecular packing change and macroscopic mechanical crystal deformations upon applied stress is still insufficient. Herein, we report that fluorescent single crystals of 9,10-dibromoanthracene are elastically bendable and stretchable, which allows a detailed investigation of the deformation behavior. We clearly observed a Poisson effect for the crystal, where the short axes (b and c-axes) of the crystal are contracted upon elongation along the long axis (a-axis). Moreover, we found that the Poisson's ratios along the b-axis and c-axis are largely different. Theoretical molecular simulation suggests that the tilting motion of the anthracene may be responsible for the large deformation along the c-axis. Spatially resolved photoluminescence (PL) measurement of the bent elastic crystals reveals that the PL spectra at the outer (elongated), central (neutral), and inner (contracted) sides are different from each other. 相似文献
92.
Waro Nakanishi Satoko Hayashi Taro Nishide Shota Otsuki 《International journal of quantum chemistry》2020,120(4):e26073
A method to elucidate the dynamic and static natures of the activated interactions in transition states (TSs) is proposed using quantum theory of atoms-in-molecules (QTAIM) dual functional analysis (QTAIM-DFA). The natures are determined for the ligand exchange at the N of sulfonylimino-λ3-bromanes, RBr-*-N(SO2CF3)-*-X′R′ (R, R′ = Me or Ph, X′ = Br′ or I′). Asterisks (*) emphasize the presence of bond critical points within the interactions in question. While data from the optimized structures of TSs correspond to the static nature, those from the perturbed and optimized structures represent the dynamic nature. The nature of the interactions in Br-*-N-*-X′ calculated with QTAIM-DFA, using the perturbed structures generated using the normal coordinates for the imaginary frequencies (NIV), was very similar to that in trigonal bipyramidal adduct formation through charge transfer. The results with NIV were precisely the same as those obtained based on intrinsic reaction coordinate (IRC). The high applicability of QTAIM-DFA is demonstrated when analyzing the activated interactions in TSs. 相似文献
93.
Shotaro Hayashi Fumitaka Ishiwari Takanori Fukushima Shohei Mikage Yutaka Imamura Motomichi Tashiro Michio Katouda 《Angewandte Chemie (International ed. in English)》2020,59(37):16195-16201
Elastic organic crystals have attracted considerable attention as next‐generation flexible smart materials. However, the detailed information on both molecular packing change and macroscopic mechanical crystal deformations upon applied stress is still insufficient. Herein, we report that fluorescent single crystals of 9,10‐dibromoanthracene are elastically bendable and stretchable, which allows a detailed investigation of the deformation behavior. We clearly observed a Poisson effect for the crystal, where the short axes (b and c‐axes) of the crystal are contracted upon elongation along the long axis (a‐axis). Moreover, we found that the Poisson's ratios along the b‐axis and c‐axis are largely different. Theoretical molecular simulation suggests that the tilting motion of the anthracene may be responsible for the large deformation along the c‐axis. Spatially resolved photoluminescence (PL) measurement of the bent elastic crystals reveals that the PL spectra at the outer (elongated), central (neutral), and inner (contracted) sides are different from each other. 相似文献
94.
Yuji Kikukawa Kensuke Seto Daiki Watanabe Hiromasa Kitajima Misaki Katayama Shohei Yamashita Yasuhiro Inada Yoshihito Hayashi 《Angewandte Chemie (International ed. in English)》2020,59(34):14399-14403
Dodecavanadate, [V12O32]4? (V12), possesses a 4.4 Å cavity entrance, and the cavity shows unique electrophilicity. Owing to the high polarizability, Br2 was inserted into V12, inducing the inversion of one of the VO5 square pyramids to form [V12O32(Br2)]4? (V12(Br2)). The inserted Br2 molecule was polarized and showed a peak at 185 cm?1 in the IR spectrum. The reaction of V12(Br2) and toluene yielded bromination of toluene at the ring, showing the electrophilicity of the inserted Br2 molecule. Compound V12(Br2) also reacted with propane, n‐butane, and n‐pentane to give brominated alkanes. Bromination with V12(Br2) showed high selectivity for 3‐bromopentane (64 %) among the monobromopentane products and preferred threo isomer among 2‐,3‐dibromobutane and 2,3‐dibromopenane. The unique inorganic cavity traps Br2 leading the polarization of the diatomic molecule. Owing to its new reaction field, the trapped Br2 shows selective functionalization of alkanes. 相似文献
95.
Koji Yamamoto Kazuki Higuchi Masahiro Ogawa Hiromitsu Sogawa Shigeki Kuwata Yoshihiro Hayashi Susumu Kawauchi Toshikazu Takata 《化学:亚洲杂志》2020,15(3):356-359
We synthesised palladium and platinum complexes possessing cyclic and acyclic pincer‐type polyaromatic ligands and investigated their structural effect on the catalysis. The pincer‐type bis(6‐arylpyridin‐2‐yl)benzene skeleton was constructed via Kröhnke pyridine synthesis under transition metal‐free conditions on gram‐scale quantity. Ligand structure significantly influenced catalytic activity toward the platinum‐catalysed hydrosilylation of diphenyl acetylenes, despite the ligand‐independence of the conformations and electronic properties of these complexes. 相似文献
96.
Shoichi Maeda Shunta Chikami Glenn Villena Latag Subin Song Norio Iwakiri Tomohiro Hayashi 《Molecules (Basel, Switzerland)》2022,27(7)
In this paper, we propose a new spectroscopic method to explore the behavior of molecules near polymeric molecular networks of water-containing soft materials such as hydrogels. We demonstrate the analysis of hydrogen bonding states of water in the vicinity of hydrogels (soft contact lenses). In this method, we apply force to hydrated contact lenses to deform them and to modulate the ratio between the signals from bulk and vicinal regions. We then collect spectra at different forces. Finally, we extracted the spectra of the vicinal region using the multivariate curve resolution-alternating least square (MCR-ALS) method. We report the hydration states depending on the chemical structures of hydrogels constituting the contact lenses. 相似文献
97.
Application of digital image analysis (DIA) to polymer blends morphology is discussed with examples. Various operations in DIA including two-dimensional Fourier transformation (2DFT), intensity distribution, recursive region extraction, etc. are applied to morphology of polymer blends due to spinodal decomposition (SD), nucleation 6 growth (NG), and eutectic solidification (ES). Merits and drawbacks of DIA to study polymer blends morphology are discussed and the possibility of future development is presented. 相似文献
98.
Kouichi Akahane Naokatsu Yamamoto Naoki Ohtani 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):295
We fabricated InAs quantum dots (QDs) with a GaAsSb strain-reducing layer (SRL) on a GaAs(0 0 1) substrate. The wavelength of emission from InAs QD is shown to be controllable by changing the composition and thickness of the SRL. An increase in photoluminescence intensity with increasing compositions of Sb and thickness of the GaAsSb SRL is also seen. The efficiency of radiative recombination was improved under both conditions because the InAs/GaAsSb/GaAs hetero-interface band structure more effectively suppressed carrier escape from the InAs QDs. 相似文献
99.
Forced fluid flow can cause the enhancement of multibubble sonoluminescence (SL) under suitable conditions. The effect of directional flow with a circulator is similar to that of rotating flow with a stirrer. The mechanism of the enhancement is that both flows prevent cavitation bubbles from coalescing and clustering, which are responsible for the quenching of SL. The intensity of sonochemiluminescence (SCL) in an aqueous luminol solution increases with flow speed at higher ultrasonic powers more significantly than that of SL in distilled water. However, in the range of low ultrasonic power, the intensities of SL and SCL decrease with flow speed. Therefore, an optimum flow speed exists in relation to ultrasonic power and frequency. 相似文献
100.
We show that entanglement guarantees difficulty in the discrimination of orthogonal multipartite states locally. The number of pure states that can be discriminated by local operations and classical communication is bounded by the total dimension over the average entanglement. A similar, general condition is also shown for pure and mixed states. These results offer a rare operational interpretation for three abstractly defined distancelike measures of multipartite entanglement. 相似文献