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61.
Masahiro Okimoto Atsushi Kawachi Yohsuke Yamamoto 《Journal of organometallic chemistry》2009,694(9-10):1419-1426
A series of 7-silanorbornadienes were prepared and characterized by X-ray crystallographic analysis. 2,3-Benzo-7-mesityl-1,4,5,6-tetraphenyl-7-silanorbornadiene (1a) was prepared by the [4+2] cycloaddition reaction of 1-mesityl-2,3,4,5-tetraphenyl-1-sila-2,4-cyclopentadiene (4) with benzyne. 7-Hydro 1a was converted into 7-chloro-substituted silanorbornadiene 1b. Treatment of 1b with lithium phenylamide and lithium phenylthiolate gave 7-phenylamino-substituted silanorbornadiene 1c and 7-phenylthio-substituted silanorbornadiene 1d, respectively. Reductive lithiation of 1b with lithium naphthalenide afforded 7-lithiated silanorbornadiene 1f, which reacted with chlorotrimethylsilane to give 7-trimethylsilyl-substituted silanorbornadiene 1e. Stereochemistry at the bridging silicon during these transformations was determined by X-ray crystallographic analysis. Thermolysis of 1 produced corresponding silylenes 5, which were trapped with triethylsilane to give disilanes 6. Photolysis of 1 except 1c also afforded corresponding silylenes 5. Theoretical calculation of the models of silanorbornadienes was performed at the MP2/6-31+G(d, p) level. 相似文献
62.
A theoretical treatment of the collisional ionization of a highly excited atom with a molecule is improved by use of the exact form factor of the hydrogen atom in highly excited states. The present treatment is still based on the previously proposed mechanism in which the Rydberg electron is ionized by gain of energy from rotational de-excitation of the molecule in a rotationally excited state. Closer comparison of experiment with theory is made for symmetric- as well as asymmetric-top molecules. 相似文献
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Dr. Lei Zhang Takumi Oishi Liuzhou Gao Shiyu Hu Linlin Yang Prof. Dr. Wei Li Shengjun Wu Prof. Dr. Rong Shang Prof. Dr. Yohsuke Yamamoto Prof. Dr. Shuhua Li Prof. Dr. Wei Wang Prof. Dr. Guxiang Zeng 《Chemphyschem》2020,21(23):2573-2578
A new efficient metal-based frustrated Lewis pair constructed by (PtBu3)2Pt and B(C6F5)3 was designed through density functional theory calculations for the catalytic dehydrogenation of ammonia borane (AB). The reaction was composed by the successive dehydrogenation of AB and H2 liberation, which occurs through the cooperative functions of the Pt(0) center and the B(C6F5)3 moiety. Two equivalents of H2 were predicted to be liberated from each AB molecule. The generation of the second H2 is the rate-determining step, with a Gibbs energy barrier and reaction energy of 27.4 and 12.8 kcal/mol, respectively. 相似文献
66.
Dimeric Tetrathiafulvalene Linked to pseudo‐ortho‐[2.2]Paracyclophane: Chiral Electrochromic Properties and Use as a Chiral Dopant 下载免费PDF全文
Kosuke Kobayakawa Dr. Masashi Hasegawa Hiroaki Sasaki Junta Endo Dr. Hideyo Matsuzawa Dr. Katsuya Sako Dr. Jun Yoshida Dr. Yasuhiro Mazaki 《化学:亚洲杂志》2014,9(10):2751-2754
A dimeric tetrathiafulvalene installed into a chiral pseudo‐ortho‐[2.2]paracyclophane framework was synthesized as a novel chiral electrochromic material. This compound exhibited pronounced chiroptical properties in the UV‐Vis‐NIR range depending on its redox states without racemization. Each enantiomer was examined as a chiral dopant for nematic liquid crystals (LCs), and the induced helicity of the LC solvent was in accord with that of the tetrathiafulvalene compound. 相似文献
67.
Ruthenium-catalyzed enantioselective propargylation of indoles with propargylic alcohols affords the corresponding beta-propargylated indoles in good yields with a high enantioselectivity (up to 95% ee). A remarkable effect of the nature of the N-substituent of indoles is observed for the enantioselectivity of the propargylated indoles. The preparative method described in this paper may provide a novel protocol for asymmetric Friedel-Crafts alkylation of indoles using propargylic alcohols as a new type of electrophiles. 相似文献
68.
Some immunological properties of mouse kidney type IV collagen (MKIVC) were investigated. In enzyme-linked immunosorbent assay (ELISA), rabbit anti-MKIVC antiserum reacted strongly with MKIVC but not at all with type I collagen or laminin of mouse origin. Thus, the purified MKIVC preparation was not contaminated with detectable amounts of other constituents of the extracellular matrix and the basement membrane including interstitial collagens, as suggested previously (T. Oikawa et al., Chem. Pharm. Bull., 34, 789 (1986)). In ELISA inhibition assay, human kidney type IV collagen (HKIVC) only partially inhibited the binding of MKIVC to anti-MKIVC antiserum. Similarly, HKIVC showed a far weaker binding capacity to the antiserum compared to MKIVC in ELISA direct binding assay. After the anti-MKIVC antiserum was absorbed with acetone powder of human kidney, the resulting antiserum still possessed a considerable binding activity to MKIVC but did not react with HKIVC. In accord with these findings, anti-MKIVC antiserum immunostained both mouse and human renal basement membranes, while it stained the former but not the latter after being absorbed with human kidney. Taken together, these results suggest that MKIVC possesses at least two antigenic determinants; one but not the other cross-reacts with human kidney basement membrane collagen. 相似文献
69.
Takemitsu Hasegawa Susumu Hibino Yohsuke Hosoda Ichizo Ninomiya 《Numerical Algorithms》2007,45(1-4):101-112
An improvement is made to an automatic quadrature due to Ninomiya (J. Inf. Process. 3:162–170, 1980) of adaptive type based on the Newton–Cotes rule by incorporating a doubly-adaptive algorithm due to Favati, Lotti and Romani
(ACM Trans. Math. Softw. 17:207–217, 1991; ACM Trans. Math. Softw. 17:218–232, 1991). We compare the present method in performance with some others by using various test problems including Kahaner’s ones (Computation
of numerical quadrature formulas. In: Rice, J.R. (ed.) Mathematical Software, 229–259. Academic, Orlando, FL, 1971).
相似文献
70.