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961.
Yue Wang Koki Ogasahara Daisuke Tomihama Dr. Radomir Mysliborski Dr. Masatoshi Ishida Yongseok Hong Yusuke Notsuka Prof. Dr. Yoshihisa Yamaoka Tomotaka Murayama Dr. Atsuya Muranaka Prof. Dr. Masanobu Uchiyama Dr. Shigeki Mori Dr. Yuhsuke Yasutake Prof. Dr. Susumu Fukatsu Prof. Dr. Dongho Kim Prof. Dr. Hiroyuki Furuta 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16295-16300
The synthesis of organometallic complexes of modified 26π-conjugated hexaphyrins with absorption and emission capabilities in the third near-infrared region (NIR-III) is described. Symmetry alteration of the frontier molecular orbitals (MOs) of bis-PdII and bis-PtII complexes of hexaphyrin via N-confusion modification led to substantial metal dπ–pπ interactions. This MO mixing, in turn, resulted in a significantly narrower HOMO–LUMO energy gap. A remarkable long-wavelength shift of the lowest S0→S1 absorption beyond 1700 nm was achieved with the bis-PtII complex, t -Pt2-3 . The emergence of photoacoustic (PA) signals maximized at 1700 nm makes t -Pt2-3 potentially useful as a NIR-III PA contrast agent. The rigid bis-PdII complexes, t -Pd2-3 and c -Pd2-3 , are rare examples of NIR emitters beyond 1500 nm. The current study provides new insight into the design of stable, expanded porphyrinic dyes possessing NIR-III-emissive and photoacoustic-response capabilities. 相似文献
962.
The effect of transition metal solutes on the lattice parameters of γ-TiAl and α2-Ti3Al were studied by first principles calculations to find suitable elements for controlling the α2/γ interfacial misfit in lamellar Ti–Al alloys. Better agreement was found between the calculated and experimental phase and site preferences of impurity atoms than in a previous first principles study. The calculated lattice parameters suggest that elements in groups 6–11 of the 4th period (Cr, Mn, Fe, Co, Ni and Cu) are effective for increasing the misfit, leading to increasing density of misfit dislocation and, in turn, higher yield strength and ductility. This effect is caused by the change in the lattice parameter of the γ-TiAl phase rather than those of α2-Ti3Al phase. This prediction agrees qualitatively with experimental data from a previous study although the effects of temperature are not taken into account. Further improvements should be possible by considering those effects. Nevertheless, the results highlight the effects of impurity addition on interfacial misfit at a level which cannot be achieved by classical concepts such as atomic size in a hard sphere model. The results will also be valuable in further more quantitative predictions and in understanding the effects of temperature, including off-stoichiometry, thermal expansion and vibration entropy. 相似文献
963.
A biphenol-based chiral phosphoric acid bearing a 9-anthryl group at each of the 3,3'-positions catalyzed the asymmetric Mannich-type reaction of N-Boc imine with difluoroenol silyl ethers in the presence of MS3A in THF to afford β-amino-α,α-difluoroketones in good yields and with excellent enantioselectivities. Optically pure 3,3-difluoroazetidin-2-one was readily synthesized from the Mannich-adduct. 相似文献
964.
The HIV-1 nucleocapsid protein (NCp7) is an emerging target for antiretroviral therapy. Five hits have been reported to inhibit the NCp7-viral nucleic acids interaction at micromolar concentrations. We used two computationally refined structures of NCp7 as receptors to propose a reliable binding pose for these compounds, by means of computational methods. Theoretical binding modes are in agreement with available experimental data. Results lay the foundations for a rationale development of more effective NCp7 inhibitors. 相似文献
965.
The concise synthesis of axially chiral biaryl diphosphine ligands by the rhodium-catalyzed intramolecular [2 + 2 + 2] cycloaddition of hexayne diphosphine oxides has been achieved. These new chiral diphosphine ligands could be employed as a ligand for the rhodium-catalyzed asymmetric catalyses. 相似文献
966.
5,12-Dicyanonaphthacene and 6,13-dicyanopentacene have been synthesized for the first time. The LUMO and HOMO levels are deepened as predicted and fabricated organic field-effect transistors (OFETs) showed ambipolar responses with carrier mobilities of 10(-3) cm(2)/V·s. 相似文献
967.
A new [X+2+Y]-type for the convergent synthesis of polycyclic ethers based on an oxiranyl anion strategy was developed. The sequence involves nucleophilic substitution of a triflate with an oxiranyl anion followed by 6-endo cyclization, ring expansion, and reductive etherification. The protocol features a flexible approach toward trans-fused polycyclic arrays consisting of six- and seven-membered ether rings from the same starting materials. 相似文献
968.
De Mori G Fu Z Viola E Cai X Ercolani C Donzello MP Kadish KM 《Inorganic chemistry》2011,50(17):8225-8237
A series of pyrazinoporphyrazine macrocycles carrying externally appended 2-thienyl rings, represented as [Th(8)TPyzPzM], where Th(8)TPyzPz = tetrakis-2,3-[5,6-di(2-thienyl)pyrazino]porphyrazinato anion and M = Mg(II)(H(2)O), Zn(II), Co(II), Cu(II), or 2H(1), were prepared and isolated as solid air-stable hydrated species. All of the compounds, completely insoluble in water, were characterized by their UV-visible spectra and electrochemical behavior in solutions of dimethylformamide (DMF), dimethyl sulfoxide, and pyridine. Molecular aggregation occurs at concentrations of ca. 10(-4) M, but monomers are formed in more dilute solutions of 10(-5) M or less. The examined octathienyl compounds [Th(8)TPyzPzM] behave as electron-deficient macrocycles, and UV-visible spectral measurements provide useful information about how the peripheral thienyl rings influence the electronic distribution over the entire macrocyclic framework. Cyclic voltammetric and spectroelectrochemical data confirm the easier reducibility of the compounds as compared to the related phthalocyanine analogues, and the overall redox behavior and thermodynamic potentials for the four stepwise one-electron reductions of the compounds are similar to those of the earlier examined octapyridinated analogues [Py(8)TPyzPzM]. Quantum yields (Φ(Δ)) for the generation of singlet oxygen, (1)O(2), the cytotoxic agent active in photodynamic therapy (PDT), and fluorescence quantum yields (Φ(F)) were measured for the Zn(II) and Mg(II) complexes, [Th(8)TPyzPzZn] and [Th(8)TPyzPzMg(H(2)O)], and the data were compared to those of corresponding octapyridino macrocycles [Py(8)TPyzPzZn] and [Py(8)TPyzPzMg(H(2)O)] and their related octacations [(2-Mepy)(8)TPyzPzZn](8+) and [(2-Mepy)(8)TPyzPzMg(H(2)O)](8+). These measurements were carried out in DMF and in DMF preacidified with HCl (ca. 10(-4) M). All of the examined Zn(II) compounds behave as excellent photosensitizers (Φ(Δ) = 0.4-0.6) both in DMF and DMF/HCl solutions, whereas noticeable fluorescence activity (Φ(F) = 0.36-0.43) in DMF/HCl solutions is shown by the Mg(II) derivatives; these data might provide perspectives for applications in PDT (Zn(II)) and imaging response and diagnosis (Mg(II)). 相似文献
969.
Aimi A Katsumata T Mori D Fu D Itoh M Kyômen T Hiraki K Takahashi T Inaguma Y 《Inorganic chemistry》2011,50(13):6392-6398
LiNbO(3)-type MnMO(3) (M = Ti, Sn) were synthesized under high pressure and temperature; their structures and magnetic, dielectric, and thermal properties were investigated; and their relationships were discussed. Optical second harmonic generation and synchrotron powder X-ray diffraction measurements revealed that both of the compounds possess a polar LiNbO(3)-type structure at room temperature. Weak ferromagnetism due to canted antiferromagnetic interaction was observed at 25 and 50 K for MnTiO(3) and MnSnO(3), respectively. Anomalies in the dielectric permittivity were observed at the weak ferromagnetic transition temperature for both the compounds, indicating the correlation between magnetic and dielectric properties. These results indicate that LiNbO(3)-type compounds with magnetic cations are new candidates for multiferroic materials. 相似文献
970.
The effects of artificial porphyrins on the electron-transport chains of living microbes were investigated. The participation of porphyrins in the microbial electron-transport chains was demonstrated by spectroscopic and current-generation measurements. Large enhancement of the microbial current generation was accomplished by adding a cationic water-soluble manganese porphyrin as an electron mediator. 相似文献