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91.
Miyasaka H Nezu T Iwahori F Furukawa S Sugimoto K Clérac R Sugiura K Yamashita M 《Inorganic chemistry》2003,42(15):4501-4503
The heterometallic Mn(II)(4)Ni(II)(2) title compound has been synthesized and characterized by X-ray crystallography. The compound consists of a Ni-Mn-Ni linear moiety, [[Ni-(mu-NO)(3)](2)-Mn], linked by oximate bridges and three Mn(II) hfac terminal units attached by oximate oxygens in a di-mu-oxo fashion, forming a novel heterometallic cluster: Mn[Mn(hfac)(2)](3)[Ni(pao)(3)](2) (1). Magnetic measurements reveal the antiferromagnetic nature of the oximate pathway between Mn(II) and Ni(II) metal ions, which imposes an unusual high-spin ground state (S = 8) for 1. 相似文献
92.
The rhodium-catalyzed addition reactions of sodium tetraphenylborate and arylboronic acids to nitriles, ketones, and imines were examined. The reaction of nitriles could be carried out efficiently in the presence of a catalyst system of [RhCl(cod)]2-dppp and H2O to give the corresponding monoarylated products selectively. Although unactivated ketones and imines are known to be poor electrophiles for rhodium-catalyzed arylation, the phenylation of them with use of sodium tetraphenylborate proceeded smoothly in the presence of [RhCl(cod)]2 and Rh(acac)(cod) as catalysts, respectively. The addition of NH4Cl was found to be crucial to effectively conduct the reaction of ketones and imines. 相似文献
93.
Masahiro Hirama 《Tetrahedron letters》1981,22(20):1905-1908
Ambident lithium carbanions of allyl phenyl sulfones add 1,4-α to both acyclic and cyclic enones exclusively if HMPA is present in the medium; in contrast, 1,2-α addition to cyclic enone is the major kinetic course in the absence of HMPA, which is followed by rearrangement to the 1,4-γ adduct. 相似文献
94.
Murakami M Usui I Hasegawa M Matsuda T 《Journal of the American Chemical Society》2005,127(5):1366-1367
Cyclobutene, having a pinacolatoboryl group at the 3-position, was prepared by the reaction of trimethyl borate with a cyclobutenyl anion, which was generated by reductive lithiation of 3-(phenylselenyl)cyclobutene. Its thermal ring-opening reaction provided (Z)-1-borylbuta-1,3-diene selectively despite the arising steric congestion. The contrasteric behavior was accounted for by assuming an electron-accepting interaction of the vacant boron p orbital with the distorted breaking sigma orbital in the inward transition state. 相似文献
95.
Masumi?Sato Masahiro?Nobe Toshiaki?DobashiEmail author Takao?Yamamoto Akira?Konno 《Colloid and polymer science》2005,284(3):293-300
We have found that the dialysis of curdlan dissolved in alkaline solution into aqueous solutions of metal salts yielded multifold gel structures. Aqueous sodium chloride and potassium chloride as well as pure water induced isotropic gels. Aqueous calcium salts induced liquid crystalline gel with refractive index gradient/amorphous gel alternative structure. Aqueous salts of trivalent aluminum and ferric cations induced a rigid liquid crystalline gel, which shrank above a threshold concentration of each salt. On the other hand, Liesegang ring-like pattern was observed with aqueous solutions of mixed salts of calcium chloride and magnesium chloride. The patterns have been classified to discuss the mechanism of forming the variety of structures. 相似文献
96.
A series of complexes, [M(bpy)(SAr)2] (M = platinum(II) or palladium(II), bpy = 2,2'-bipyridine, SAr = 2- or 4-(acylamino)benzenethiolate, or 2-(alkylcarbamoyl)benzenethiolate), were synthesized and characterized on the basis of 1H NMR, IR, and electrochemical properties. The structures of [Pt(bpy)(S-2-Ph3CCONHC6H4)2] (1) and [Pt(bpy)(S-2-t-BuNHCOC6H4)2] (3) were determined by X-ray analysis. The complexes have intramolecular NH...S hydrogen bonds between the amide NH group and the sulfur atom. A weak NH...S hydrogen bond in these complexes and [Pd(bpy)(S-2-Ph3CCONHC6H4)2] (4) is detected from the 1H NMR spectra and the IR spectra in chloroform and in the solid state. [Pt(bpy)(S-2-Ph3CCONHC6H4)2] (1) exhibits a remarkably high-energy-shifted lowest-energy band in UV-visible spectra and has a positively shifted oxidation potential. The blue-shift of 42 nm and the positive shift of +0.24 V, as compared to those of [Pt(bpy)(SC6H5)2), are due to the effect of the NH...S hydrogen bond. 相似文献
97.
Uchida K Saito M Murakami A Kobayashi T Nakamura S Irie M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(2):534-542
A photochromic polymer film containing three different diarylethene derivatives, that is, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (3) was prepared. Upon UV irradiation, the three derivatives changed to their closed-ring isomers having different colors, yellow, red, and blue. They showed different spectra not only in UV/Vis region but also in the IR spectral region. Upon irradiation with visible light of appropriate wavelengths, each closed-ring isomer was selectively bleached, and three bits eight states recording was performed. The eight states could be read out nondestructively by using IR light of appropriate wavenumbers. 相似文献
98.
Takashi Kajiwara Kensuke Katagiri Shinya Takaishi Masahiro Yamashita Nobuhiko Iki 《化学:亚洲杂志》2006,1(3):349-351
A dodecaholmium wheel of [Ho12(L)6(mal)4(AcO)4(H2O)14] ( 1 ; mal=malonate) was synthesized by using p‐tert‐butylsulfonylcalix[4]arene (H4L) as a cluster‐forming ligand. The wheel consists of three fragments of mononuclear A3? ([Ho(L)(mal)(H2O)]3?), trinuclear B3? ([Ho(H2O)2(mal)(Ho(L)(AcO))2]3?), and C3+ ([Ho(H2O)2]3+), and an alternate arrangement of these fragments (A3?? C3+? B3?? C3+? A3?? C3+? B3?? C3+? ) results in a wheel structure. The longest and shortest diameters of the core were estimated to be 17.7562(16) and 13.6810(13) Å, respectively, and the saddle‐shaped molecule possesses a pocketlike cavity inside. 相似文献
99.
Masahiro Yoshida 《Tetrahedron letters》2004,45(9):1861-1864
Substituted 2,3-dihydrofurans and benzofurans are synthesized by the palladium-catalyzed reaction of 5-methoxycarbonyloxy-3-pentyn-1-ols and 1-(2-hydroxyphenyl)-3-methoxycarbonyloxy-1-propyne with nucleophiles, respectively. Various substituted propargylic carbonates and nucleophiles are efficiently transformed to their corresponding products. Additionally, a reaction using substrates containing a nucleophilic phenoxy group within the same molecule also produces the corresponding dihydrofuran. 相似文献
100.
Soh N Imato T Kawamura K Maeda M Katayama Y 《Chemical communications (Cambridge, England)》2002,(22):2650-2651
A novel fluorescent probe, which could be the first example of a ratiometric molecular probe for direct monitoring of NO production, has been developed using a 'spin-exchange' mechanism. 相似文献