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121.
The title compound (2,9-DClQA) is a hydrogen-bonded, bluish-red pigment. However, red and black single crystals have been isolated from the vapor phase in the higher- and lower-temperature regions around 380 and 150 degrees C, respectively. Because of this, correlation has been studied in the present investigation between the crystal structure and the shade in the solid state. The red phase is found to correspond to the commercial product as characterized by two-dimensional NH...O hydrogen bonds between the NH group of one molecule and the O atom of the neighboring one. On the other hand, the molecule of the black phase is heavily deformed and no intermolecular hydrogen bonds are recognized. The molecular distortion induced by crystallization in the black phase is found to displace the absorption band toward longer wavelengths to bring about the black color. In addition, the black phase is observed to be transformed into the red one around 200 degrees C. 相似文献
122.
Quinolone Analogs 13: Synthesis of Novel 1,1′‐(2‐Methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) and Related Compounds
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Yoshihisa Kurasawa Kiminari Yoshida Naoki Yamazaki Eisuke Kaji Kenji Sasaki Yoshito Zamami Takatoshi Fujii Min Zhao Hideyuki Ito Haruhiko Fukaya 《Journal of heterocyclic chemistry》2014,51(6):1720-1726
The reaction of the 4‐hydroxyquinoline‐3‐carboxylate 6 with pentaerythritol tribromide gave the 1,1′‐(2‐methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 11 , whose reaction with bromine afforded the 1,1′‐(2‐bromo‐2‐bromomethylpropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 12 . Compound 12 was transformed into the (Z)‐1,1′‐(2‐acetoxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 13 or (E)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylate) 14 . Hydrolysis of the dimer (Z)‐ 13 or (E)‐ 14 with potassium hydroxide provided the (E)‐1,1′‐(2‐hydroxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylic acid) 15 or (Z)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylic acid) 16 , respectively. The nuclear Overhauser effect (NOE) spectral data supported that those hydrolysis resulted in the geometrical conversion of (Z)‐ 13 into (E)‐ 15 or (E)‐ 14 into (Z)‐ 16 . 相似文献
123.
Takatoshi Ichino Dr. Stephanie M. Villano Dr. Adam J. Gianola Dr. Daniel J. Goebbert Dr. Luis Velarde Dr. Andrei Sanov Prof. Stephen J. Blanksby Dr. Xin Zhou Dr. David A. Hrovat Dr. Weston Thatcher Borden Prof. W. Carl Lineberger Prof. 《Angewandte Chemie (International ed. in English)》2009,48(45):8381-8381
124.
Rosaio L. Reserva Dennis C. Arogancia Angelina M. Bacala Khalil Boudjemline Dan Burke Paul Colas Madhu Dixit Arnaud Giganon Ioannis Giomataris Hermogenes C. Gooc Jr Yukihiro Kato Keisuke Fujii Hiroyuki Fujishima Masahiro Habu Takatoshi Higashi Makoto Kobayashi Hirotoshi Kuroiwa Vincent Lepeltier Takeshi Matsuda Osamu Nitoh Kirsten Sachs Ronald Dean Settles Akira Sugiyama Philippe Rosier Sachio Matsushita Keiichi Nakamura Takashi Watanabe Atsushi Yamaguchi Hiroshi Yamaoka Thomas Zerguerras 《Pramana》2007,69(6):989-994
R&D studies on the performance as well as on the gas properties of the microMEGAS-based time projection chamber with standard
readout were carried out in June 2005 using 4 GeV/c pion beam in a magnetic field from 0 to 1 T at the proton synchrotron
beam line at KEK, Japan. Analysis of the electron drift velocity, diffusion constant and point resolution of padrow measurement
for MicroMEGAS TPC filled with 95% argon and 5% isobutane gas are presented. The underlying physical mechanism which determines
the optimal TPC performance are briefly discussed. Preliminary measurements of gas properties and spatial resolution in close
agreement with the analytical calculation and MAGBOLTZ simulation are summarized and presented in this paper.
相似文献
125.
Takatoshi Sawai Kazunobu Sato Daisuke Shiomi Kazuo Toyota Qi Wang Jia-Song Wang Yong Li Guo-Shi Wu Takeji Takui 《Applied magnetic resonance》2011,41(2-4):337-352
A calix[4]arene-based biradical with two tert-butyl nitroxide radicals and a monoradical derived from the biradical have been studied by continuous-wave electron spin resonance (CW-ESR) and pulse-ESR-based hyperfine sublevel correlation (HYSCORE) spectroscopy. The two nitroxide radical sites antiferromagnetically interact with each other, generating a thermally accessible triplet state located 4?cm?1 above the singlet ground state. The present fine-structure and hyperfine spectral simulation for the spin Hamiltonian parameters of the biradical is sensitive to the local molecular structure at the spin-bearing site, illustrating a salient electronic structure of the radical sites with the ??-orbitals on the nitrogen (and oxygen) atoms cross-facing each other. The derived structure contrasts with the molecular structure determined by an X-ray crystal analysis for the hydroxylamine precursor of the biradical. The distance between the two midpoints of the nitrogen?Coxygen bonds at the radical sites is by 0.234?nm longer than the one (=0.314?nm) of the two hydroxyl groups of the precursor determined by the X-ray analysis. The lack of intramolecular hydrogen bonds between the nitrogen and hydrogen of the hydroxyl groups, caused by the oxidation of the hydroxyamino precursor, gives rise to such a sizable increase in the distance between the radical sites. The HYSCORE experiments gave a direct evidence of the local molecular structure of the radical site of the partially oxidized monoradical. The experimentally derived molecular structures of both the bi-, monoradicals and the precursor are in good agreement with those obtained by density functional theory calculations. 相似文献
126.
Kenichiro Inoue Shinichi Ueda Yoshinori Shiobara Hiroyuki Inouye 《Tetrahedron letters》1980,21(7):621-622
The main biosynthetic route from 4-(2′-carboxyphenyl)-4-oxobutanoic acid (1) via 2-carboxy-4-oxo-1-tetralone (COT) to several quinonoids in callus cultures of Catalpa ovata was definitely demonstrated to pass stereospecifically through (2S)-prenyl-COT ((2S)-2) and (2R)-catalponone ((2R)-3). 相似文献
127.
128.
Mitsuaki Kodama Yoshinori Shiobara Katsuki Matsumura Hisako Sumitomo 《Tetrahedron letters》1985,26(7):877-880
Total synthesis of marchantin A, a novel cytotoxic bis(bibenzyl) isolated from some liverworts, has been accomplished in 12 steps. 相似文献
129.
130.
Yaoita T Isaki T Masubuchi Y Watanabe H Ianniruberto G Greco F Marrucci G 《The Journal of chemical physics》2004,121(24):12650-12654
The concept of dynamic tube dilation (DTD) is here used to formulate a new simulation scheme to obtain the linear viscoelastic response of long chains with a large number of entanglements. The new scheme is based on the primitive chain network model previously proposed by some of the authors, and successfully employed to simulate linear and nonlinear behavior of moderately entangled polymers. Scaling laws are generated by the DTD concept, and allow for prediction of the linear response of very long chains on the basis of suitable simulations performed on shorter ones, without introducing adjustable parameters. Tests of the method against existing data for linear monodisperse polyisoprene and polystyrene show good quantitative agreement. 相似文献