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41.
Yasunori Muranishi Nobuo Okabe 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):m578-m580
trans‐Diaquabis(isoquinoline‐1‐carboxylato‐κ2N,O)cobalt(II) dihydrate, [Co(C10H6NO2)2(H2O)2]·2H2O, and trans‐diaquabis(isoquinoline‐1‐carboxylato‐κ2N,O)nickel(II) dihydrate, [Ni(C10H6NO2)2(H2O)2]·2H2O, contain the same isoquinoline ligand, with both metal atoms residing on a centre of symmetry and having the same distorted octahedral coordination. In the former complex, the Co—O(water) bond length in the axial direction is 2.167 (2) Å, which is longer than the Co—O(carboxylate) and Co—N bond lengths in the equatorial plane [2.055 (2) and 2.096 (2) Å, respectively]. In the latter complex, the corresponding bond lengths for Ni—O(water), Ni—O(carboxylate) and Ni—N are 2.127 (2), 2.036 (2) and 2.039 (3) Å, respectively. Both crystals are stabilized by similar stacking interactions of the ligand, and also by hydrogen bonds between the hydrate and coordinated water molecules. 相似文献
42.
Ohki Y Matsuura N Marumoto T Kawaguchi H Tatsumi K 《Journal of the American Chemical Society》2003,125(26):7978-7988
A series of sulfido-bridged tungsten-ruthenium dinuclear complexes Cp*W(mu-S)(3)RuX(PPh(3))(2) (4a; X = Cl, 4b; X = H), Cp*W(O)(mu-S)(2)RuX(PPh(3))(2) (5a; X = Cl, 5b; X = H), and Cp*W(NPh)(mu-S)(2)RuX(PPh(3))(2) (6a; X = Cl, 6b; X = H) have been synthesized by the reactions of (PPh(4))[Cp*W(S)(3)] (1), (PPh(4))[Cp*W(O)(S)(2)] (2), and (PPh(4))[Cp*W(NPh)(S)(2)] (3), with RuClX(PPh(3))(3) (X = Cl, H). The heterolytic cleavage of H(2) was found to proceed at room temperature upon treating 5a and 6a with NaBAr(F)(4) (Ar(F) = 3, 5-C(6)H(3)(CF(3))(2)) under atmospheric pressure of H(2), which gave rise to [Cp*W(OH)(mu-S)(2)RuH(PPh(3))(2)](BAr(F)(4)) (7a) and [Cp*W(NHPh)(mu-S)(2)RuH(PPh(3))(2)](BAr(F)(4)) (8), respectively. When Cp*W(O)(mu-S)(2)Ru(PPh(3))(2)H (5b) was treated with a Br?nstead acid, [H(OEt(2))(2)](BAr(F)(4)) or HOTf, protonation occurred exclusively at the terminal oxide to give [Cp*W(OH)(mu-S)(2)RuH(PPh(3))(2)](X) (7a; X = BAr(F)(4), 7b; X = OTf), while the hydride remained intact. The analogous reaction of Cp+W(mu-S)(3)Ru(PPh(3))(2)H (4b) led to immediate evolution of H(2). Selective deprotonation of the hydroxyl group of 7a or 7b was induced by NEt(3) and 4b, generating Cp*W(O)(mu-S)(2)Ru(PPh(3))(2)H (5b). Evolution of H(2) was also observed for the reactions of 7a or 7b with CH(3)CN to give [Cp*W(O)(mu-S)(2)Ru(CH(3)CN)(PPh(3))(2)](X) (11a; X = BAr(F)(4), 11b; X = OTf). We examined the H/D exchange reactions of 4b, 5b, and 7a with D(2) and CH(3)OD, and found that facile H/D scrambling over the W-OH and Ru-H sites occurred for 7a. Based on these experimental results, the mechanism of the heterolytic H(2) activation and the reverse H(2) evolution reactions are discussed. 相似文献
43.
The crystal structures of the series of four ternary complexes, [Pd(phen)(2,6-PDCA)].4H(2)O (1) (phen=1,10-phenanthroline; 2,6-PDCA=2,6-pyridinedicarboxylic acid), [Pd(bpy)(2,3-PDCA)].3H(2)O (2) (bpy=2,2'-bipyridineand; 2,3-PDCA=2,3-pyridinedicarboxylic acid) and [Pd(phen)(PHT)].2.5H(2)O (3) (PHT=o-phthalic acid ) and [Pd(bpy)(PHT)].1.5H(2)O (4), are determined and the coordination modes of palladium(II) ternary complexes are characterized. All complexes take the mononuclear Pd(II) complexes, in which central Pd(II) atom of each complex has a similar distorted square-planar four coordination geometry. In all complexes, the aromatic heterocyclic compounds, phen and bpy, behave as a bidentate N, N' ligand. In the complex 1 and 2, 2,6-PDCA and 2,3-PDCA behave as a bidentate N, O ligand, and in complex 3 and 4, PHT behaves as a bidentate O, O' ligand. 相似文献
44.
Naoya Hosoda Hideaki Kamito Miki Takano Yoshitaka Takebe Yoshitaka Yamaguchi Masatoshi Asami 《Tetrahedron》2013,69(6):1739-1746
Chiral diamines, 2-(anilinophenylmethyl)pyrrolidines and 2-(anilinodiphenylmethyl)pyrrolidine, were prepared from N-(tert-butoxycarbonyl)pyrrolidine or (S)-proline as a starting material, respectively. These chiral diamines were efficient for the catalytic enantioselective borane reduction of acetophenone. Using (S)-2-(anilinodiphenylmethyl)pyrrolidine, chiral secondary alcohols were obtained from prochiral ketones with good to excellent enantiomeric excesses (up to 98% ee). 相似文献
45.
Junling Bai Toshifumi Nakatani Yuuki Sasaki Sadanobu Inoue Nobuo Takahashi 《International journal of environmental analytical chemistry》2013,93(9):856-865
Effectiveness of Pd/Mg chemical modifier for the accurate direct determination of zinc in marine/lacustrine sediments by graphite furnace atomic absorption spectrometry (GF-AAS) using slurry samples was evaluated. A calibration curve prepared by aqueous zinc standard solution with addition of Pd/Mg chemical modifier is used to determine the zinc concentration in the sediment. The accuracy of the proposed method was confirmed using Certified Reference Materials, NMIJ CRM 7303-a (lacustrine sediment) from National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Japan, and MESS-3 (marine sediment) and PACS-2 (marine sediment) from National Research Council, Canada. The analytical results obtained by employing Pd/Mg modifier are in good agreement with the certified values of all the reference sediment materials. Although for NRC MESS-3 an accurate determination of zinc is achieved even without the chemical modifier, the use of Pd/Mg chemical modifier is recommended as it leads to establishment of a reliable and accurate direct analytical method. One quantitative analysis takes less than 15 minutes after we obtain dried sediment samples, which is several tens of times faster than conventional analytical methods using acid digested sample solutions. The detection limits are 0.13?µg?g?1 (213.9?nm) and 16?µg?g?1 (307.6?nm), respectively, in sediment samples, when 40?mg of dried powdered samples are suspended in 20?mL of 0.1?mol?L?1 nitric acid and a 10?µl portion of the slurry sample is measured. The precision of the proposed method is 8–15% (RSD). 相似文献
46.
Ryoma Masuda Yuuya Kawasaki Kazunobu Igawa Yoshiyuki Manabe Hiroshi Fujii Nobuo Kato Katsuhiko Tomooka Junko Ohkanda 《化学:亚洲杂志》2020,15(6):742-747
Mid‐sized molecules have emerged as an attractive chemical space and potentially provide a robust basis for the development of synthetic agents to control intracellular protein interactions. However, the limited cell permeability and chemical tractability of such agents remain to be addressed. We envisioned that target‐templated synthesis of such mid‐sized molecules might provide a solution. Here, we exploited a copper‐free Huisgen cycloaddition for template synthesis using a peptide fragment containing a 4,8‐diazacyclononyne (DACN) moiety and an azide‐containing fusicoccin derivative in the presence or absence of recombinant 14‐3‐3ζ protein in vitro. Time‐course changes in the yield of products demonstrated that the reaction was accelerated in the presence of 14‐3‐3 and one of the regioisomers was generated predominantly, supporting the template effect. 相似文献
47.
New phenylethanoid glycosides from Bacopa monniera 总被引:1,自引:0,他引:1
Chakravarty AK Sarkar T Nakane T Kawahara N Masuda K 《Chemical & pharmaceutical bulletin》2002,50(12):1616-1618
Three new phenylethanoid glycosides, viz. monnierasides I-III (1-3) along with the known analogue plantainoside B were isolated from the glycosidic fraction of Bacopa monniera. Their structures were elucidated mainly on the basis of two dimensional (2D) NMR spectral analyses. 相似文献
48.
A continuum limit of the Toda lattice field theory, called the SDiff(2) Toda equation, is shown to have a Lax formalism and an infinite hierarchy of higher flows. The Lax formalism is very similar to the case of the self-dual vacuum Einstein equation and its hyper-Kähler version, however now based upon a symplectic structure on a cylinderS
1×R. An analogue of the Toda lattice tau function is introduced. The existence of hidden SDiff(2) symmetries are derived from a Riemann-Hilbert problem in the SDiff(2) group. Symmetries of the tau function turn out to have commutator anomalies, hence give a representation of a central extension of the SDiff(2) algebra. 相似文献
49.
50.