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排序方式: 共有195条查询结果,搜索用时 15 毫秒
11.
Nobuko Watanabe 《Tetrahedron》2005,61(40):9569-9585
Dioxetanes (1) bearing a phenyl moiety substituted with a methylene or methine having an electron-withdrawing group(s) (-CH2-Ew or -CH(X)-Ew) and dioxetane (2) bearing a 3-(1-cyanoethenyl)phenyl group were synthesized. Treatment of dioxetanes (1) with tetrabutylammonium fluoride (TBAF) caused their decomposition with accompanying emission of light with maximum wavelength at 530-758 nm. The Michael addition of a bis(methoxycarbonyl)methanide anion to dioxetane (2) produced initially an unstable dioxetane bearing a phenylmethanide anion, decomposition of which gave light with maximum wavelength at 710-740 nm. Intramolecular cyclopropanation without decomposition of the dioxetane ring took place concurrently for the Michael reaction-induced decomposition of 2 with the bis(methoxycarbonyl)chloromethanide anion. 相似文献
12.
Qiang Xu Prof. Dr. Nobuko Tsumori Prof. Dr. Ling Jiang Masanobu Kondo Ryuichi Arakawa Prof. Dr. 《化学:亚洲杂志》2007,2(5):599-608
Carbonyldinitrosyltris(fluorosulfato)tungstate(II) and ‐molybdate‐(II) anions, [fac‐M(CO)(NO)2(SO3F)3]? (M=W, Mo), which are novel weakly coordinating anions that contain a metal carbonyl/nitrosyl moiety, have been generated in fluorosulfonic acid and completely characterized by multinuclear NMR, IR, and Raman spectroscopy as well as ESI mass spectrometry. ESI MS measurements performed for the first time on a superacidic solution system unambiguously reveal the formation of the monoanionic, mononuclear W and Mo complexes formulated as [M(CO)(NO)2(SO3F)3]? (M=W, Mo). Multinuclear NMR spectroscopic studies at natural abundance and 13C and 15N enrichment clearly indicate the presence of one CO ligand, two equivalent NO ligands, and two types of nonequivalent SO3F? groups in a 2:1 ratio. The IR and Raman spectra reveal that the two equivalent NO ligands have a cis conformation, thus indicating a fac structure. Density functional calculations at the B3LYP level of theory predict that these anions have a singlet ground state (1A′) with a Cs symmetry along with C–O and N–O vibrational frequencies that are in agreement with the experimental observations. Mulliken population analysis shows that the monovalent negative charge is dispersed on the bulky sphere, the surface of which is covered by all the negatively charged O and F atoms with charge densities much lower than SO3F?, suggesting that [fac‐M(CO)(NO)2(SO3F)3]? (M=W, Mo) are weakly nucleophilic and poorly coordinating anions. 相似文献
13.
Nobuko WatanabeYasuhiro Nagashima Takahiro YamazakiMasakatsu Matsumoto 《Tetrahedron》2003,59(26):4811-4819
Tetrabutylammonium fluoride induces the decomposition of 1-tert-butyl-4,4-dimethyl-5-(3-siloxyphenyl)-2,6,7-trioxabicyclo[3.2.0]heptane (4a) in DMSO to form an oxyanion of aromatic ketone (14a) as an emitter with high singlet-chemiexcitation yield comparable with that for a chemically initiated electron exchange luminescence (CIEEL) active dioxetane producing an oxyanion of aromatic ester as an emitter. A 7-siloxynaphthalen-2-yl analog (4b) was found on similar treatment to emit light with the maximum wavelength the longest among CIEEL-active dioxetanes hitherto known. 相似文献
14.
Kitaura R Iwahori F Matsuda R Kitagawa S Kubota Y Takata M Kobayashi TC 《Inorganic chemistry》2004,43(21):6522-6524
A new three-dimensional (3-D) jungle-gym-like open metal-organic framework has been synthesized from a two-dimensional (2-D) layer compound using a heterogeneous pillar insertion reaction. Both the starting 2-D layer and the resulting 3-D open compounds have been characterized using X-ray crystallography. 相似文献
15.
The photochromic ligand bis(terpyridyl)hexaarylbiimidazole (bistpy-HABI) and the Fe(II) complex of bistpy-HABI with formula [{Fe(tpy)}2.bistpy-HABI](PF6)4.4H2O were synthesized and characterized. Bistpy-HABI is readily cleaved into a pair of terpyridyltriphenylimidazolyl radicals (tpy-TPI*) on irradiation with UV light. This photochemical reaction is completely reversible, and the light-induced radicals can thermally recombine to form bistpy-HABI in the dark. [{Fe(tpy)}2.bistpy-HABI]4+ is the first example of a transition-metal complex of an HABI derivative and was found to show photochromic reaction in solution. The spin state of the light-induced radical pair in a frozen matrix was investigated by ESR spectroscopy. The triplet state of the light-induced radical pair from [{Fe(tpy)}2.bistpy-HABI]4+, as well as that from bistpy-HABI, was confirmed to be a ground state or nearly degenerated with a singlet state. Kinetic studies on the radical recombination reaction in solution elucidated the decrease in the activation energy by forming the Fe(II) complex. This is the first observation of a decrease in the activation energy of the radical recombination reaction by the formation of a metal-coordinated radical complex. The syntheses, photochemical properties, and spin states of bistpy-HABI and [{Fe(tpy)}2.bistpy-HABI](PF6)4 are discussed. 相似文献
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17.
Organic Dicarboxylate Negative Electrode Materials with Remarkably Small Strain for High‐Voltage Bipolar Batteries
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Dr. Nobuhiro Ogihara Tomomi Yasuda Yoshihiro Kishida Dr. Tetsu Ohsuna Kaito Miyamoto Dr. Nobuko Ohba 《Angewandte Chemie (International ed. in English)》2014,53(43):11467-11472
As advanced negative electrodes for powerful and useful high‐voltage bipolar batteries, an intercalated metal–organic framework (iMOF), 2,6‐naphthalene dicarboxylate dilithium, is described which has an organic‐inorganic layered structure of π‐stacked naphthalene and tetrahedral LiO4 units. The material shows a reversible two‐electron‐transfer Li intercalation at a flat potential of 0.8 V with a small polarization. Detailed crystal structure analysis during Li intercalation shows the layered framework to be maintained and its volume change is only 0.33 %. The material possesses two‐dimensional pathways for efficient electron and Li+ transport formed by Li‐doped naphthalene packing and tetrahedral LiO3C network. A cell with a high potential operating LiNi0.5Mn1.5O4 spinel positive and the proposed negative electrodes exhibited favorable cycle performance (96 % capacity retention after 100 cycles), high specific energy (300 Wh kg?1), and high specific power (5 kW kg?1). An 8 V bipolar cell was also constructed by connecting only two cells in series. 相似文献
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19.
Masahiro Yamashita Daisuke Kawakami Satoshi Matsunaga Yoshio Nakayama Mari Sasaki Shinya Takaishi Fumiyasu Iwahori Hitoshi Miyasaka Ken‐ichi Sugiura Yoshiki Wada Hiroshi Miyamae Hiroyuki Matsuzaki Hiroshi Okamoto Hisaaki Tanaka Kazuhiro Marumoto Shin‐ichi Kuroda 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2004,116(36):4867-4871
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