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51.
Kinugawa T Yabushita A Kawasaki M Hama T Watanabe N 《Physical chemistry chemical physics : PCCP》2011,13(35):15785-15791
Photodissociation of amorphous ice films of carbon dioxide and water co-adsorbed at 90 K was carried out at 157 nm using oxygen-16 and -18 isotopomers with a time-of-flight photofragment mass spectrometer. O((3)P(J)) atoms, OH (v = 0) radicals, and CO (v = 0,1) molecules were detected as photofragments. CO is produced directly from the photodissociation of CO(2). Two different adsorption states of CO(2), i.e., physisorbed CO(2) on the surface of amorphous solid water and trapped CO(2) in the pores of the film, are clearly distinguished by the translational and internal energy distributions of the CO molecules. The O atom and OH radical are produced from the photodissociation of H(2)O. Since the absorption cross section of CO(2) is smaller than that of H(2)O at 157 nm, the CO(2) surface abundance is relatively increased after prolonged photoirradiation of the mixed ice film, resulting in the formation of a heterogeneously layered structure in the mixed ice at low temperatures. Astrophysical implications are discussed. 相似文献
52.
Tatsuya Sakakura Assoc. Prof. Naoya Murakami Dr. Yoshiyuki Takatsuji Masayuki Morimoto Prof. Tetsuya Haruyama 《Chemphyschem》2019,20(11):1467-1474
Electric-discharge nitrogen comprises three main types of excited nitrogen species-atomic nitrogen (Natom), excited nitrogen molecules (N2*), and nitrogen ions (N2+) – which have different lifetimes and reactivities. In particular, the interfacial reaction locus between the discharged nitrogen and the water phase produces nitrogen compounds such as ammonia and nitrate ions (denoted as N-compounds generically); this is referred to as the plasma/liquid interfacial (P/L) reaction. The Natom amount was analyzed quantitatively to clarify the contribution of Natom to the P/L reaction. We focused on the quantitative relationship between Natom and the produced N-compounds, and found that both N2* and N2+, which are active species other than Natom, contributed to P/L reaction. The production of N-compounds from N2* and N2+ was enhanced upon UV irradiation of the water phase, but the production of N-compounds from Natom did not increase by UV irradiation. These results revealed that the P/L reactions starting from Natom and those starting from N2* and N2+ follow different mechanisms. 相似文献
53.
Shinya Hayami Yasuka Komatsu Tetsuya Shimizu Hidenobu Kamihata Young Hoon Lee 《Coordination chemistry reviews》2011,255(17-18):1981-1990
In this review article we discuss the unique and novel magnetic properties for the cobalt(II) compounds with a variety of terpy derivatives including substituents at the 4-position. These are also compared with the unsubstituted terpy cobalt(II) complex. Since the first SCO cobalt(II) complex with terpy ligand was reported, this system has been widely studied. SCO cobalt(II) complexes possessing terpy or OH-terpy ligand reveal incomplete or gradual SCO behavior. The pyterpy-appended cobalt(II) complex shows SCO depending on the guest molecules involved. Cobalt(II) complexes with long-alkylated terpy ligands, [Co(Cn-terpy)2](BF4)2 (n = 16, 14 and 12) have been synthesized and some were characterized by single crystal X-ray analysis. Furthermore, variable-temperature magnetic susceptibility indicated that the non-solvated compounds [Co(Cn-terpy)2](BF4)2 (n = 16, 14 and 12) exhibit “reverse spin transition” phenomenon with wide thermal hysteresis around room temperature. In addition, the solvated compound [Co(C12-terpy)2](BF4)2·EtOH·0.5H2O shows “re-entrant SCO” behavior. The long alkyl chains in SCO cobalt(II) complexes can lead to novel physical properties resulting from a synergetic effect between SCO and response of the flexibility toward external stimuli. 相似文献
54.
Shapes and orientational deformation of a lipid monolayer domain have been analyzed taking into account the surface pressure, line tension, and electrostatic energy due to the spontaneous polarization and electric quadrupole density generated from the domain. The electrostatic energy due to the generation of spontaneous polarization and electric quadrupole density contributes to the formation of orientational deformation as the Frank elastic energy and spontaneous splay, respectively. Since the orientational configuration of the electric quadrupole density and in-plane spontaneous polarization is dependent on the molecular chirality, and the positive splay deformation of electric quadrupole density is induced by the spontaneous splay, the bending direction of in-plane spontaneous polarization depends on the chirality of constituent lipids. The electrostatic energy due to the in-plane spontaneous polarization is dependent on the orientational deformation of in-plane spontaneous polarization, and bends the domain shape towards the bending direction of the in-plane spontaneous polarization. It has been demonstrated that the chiral dependence of the domain shapes of lipid monolayers originated from the chiral dependence of orientational structure due to the electric quadrupole density. 相似文献
55.
Itsuki Shindachi Hiroshi Hanaki Ryo Sasai Tetsuya Shichi Tatsuto Yui Katsuhiko Takagi 《Research on Chemical Intermediates》2007,33(1-2):143-153
Diarylethene derivatives (DE) covalently bonded to silanol oxygens of layered silicate surfaces, i.e., magadiite (Mag), were synthesized and investigated for their photochromic behavior. The DE-Mag layered hybrids were found to undergo reversible color change by alternating UV and visible light irradiation. A more highly efficient, reproducible photochromic behavior was realized with DE-Mag than with a corresponding DE-Si possessing silyl substituents on DE in place of the Mag surface. Moreover, the present covalently bonded DE exhibited an improvement over DE hybrids incorporated in layered double hydroxide (LDH) clays, in which the repetitive photochromic behavior decreased during alternating irradiation, due to the accumulation of the photochemically inert parallel isomers of DE. 相似文献
56.
A wide range of o-alkynylanilines undergo a copper-catalyzed direct C-H/N-H coupling with azoles followed by benzannulation to form the corresponding N-azolylindoles in good yields. The domino reaction proceeds effectively with molecular oxygen as the sole oxidant and provides a new dehydrogenative access to the titled compounds of interest in pharmaceutical and material sciences. 相似文献
57.
Aida H Mori K Yamaguchi Y Mizuta S Moriyama T Yamamoto I Fujimoto T 《Organic letters》2012,14(3):812-815
A phosphinite derivative that can be easily prepared in two steps from commercially available aminoindanol was found to be an effective catalyst for enantioselective acylation of diols. For the asymmetric desymmetrization of meso-1,2-diols, the corresponding monoester was obtained in up to 95% ee from the reaction in the presence of 5 mol % catalyst. 相似文献
58.
Adsorption and photochemical behaviors of the novel cationic xanthene derivative on the clay surface
Yuta Ohtani Yohei Ishida Yuka Ando Hiroshi Tachibana Tetsuya Shimada Shinsuke Takagi 《Tetrahedron letters》2014
Novel tetra-cationic xanthene derivative (Flu) was synthesized. Its adsorption and photochemical behaviors on the clay surface were investigated. Fluorescence quantum yield (?f) and fluorescence lifetime were 0.50 and 2.9 ns for Flu/clay complex. ?f of Flu was enough high (>0.1) even at high density conditions (0.080 molecules nm−2). It is supposed that the strong interaction between clay and Flu by the ‘Size-Matching Effect’ realizes the highly emissive clay complexes at high density adsorption condition by a suppression of a molecular aggregation, which tends to decrease the photochemical activity. 相似文献
59.
Craig L. Bull Tetsuya Kawashima Paul F. McMillan Denis Machon Dominik Daisenberger E. Takayama-Muromachi 《Journal of solid state chemistry》2006,179(6):1762-1767
We prepared samples of cubic γ-MoNx (x∼0.5) by high-pressure-high-temperature synthesis. N atom site occupancies within the defect rock salt structure were determined from time-of-flight neutron diffraction and powder X-ray diffraction data by Rietveld analysis. The results show that N atoms occupy only octahedral sites within the structure. The semi-metallic compound is a superconductor, with determined by SQUID magnetometry. The compressibility of the material was determined by synchrotron X-ray diffraction measurements at high pressure in the diamond anvil cell. The vibrational density of states was studied by Raman scattering spectroscopy. 相似文献
60.
Yoshitomo Kashiwagi Yumiko Takamori Kentaro Yoshida Tetsuya Ono 《Electroanalysis》2013,25(12):2575-2577
This paper describes the electrocatalytic oxidation of amines on TEMPO (2,2,6,6‐tetramethylpiperidine‐1‐oxyl)‐modified electrodes prepared by electrochemical copolymerization of TEMPO precursor containing pyrrole side chain and 2,2′‐bithiophene. The modified electrode exhibits electrocatalytic activity for the oxidation of primary and secondary amines. Cyclic voltammetric studies showed that the peak current of the cyclic voltammogram increased linearly with increasing concentration of amine in the sample solution. 相似文献