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Taoyun Zhu Koichi Murokawa Kazuyoshi Uematsu Tadashi Ishigaki Kenji Toda Hirokazu Okawa Mineo Sato 《Polyhedron》2009
This paper represents the hydrothermal synthesis of new isomorphous lanthanide–vanadium complexes with one-dimensional coordination polymers: [Pr2(VO2)2(dipic)4(H2O)9] · nH2O with dipic = pyridine-2,6-dicarboxylic acid and n = 7.75. The structure determination shows a unique one-dimensional structure in which three types of chains run along the c-axis: the chain of positively charged praseodymium complexes bridged by a dipic ligand ([Pr(dipic)(H2O)5]+), the chain of negatively charged, stacked vanadium complexes ([VO2(dipic)]−), and the chain of neutral praseodymium complexes with a bridged dipic ligand and a coordinating dipic ligand ([Pr(dipic)[VO2(dipic)](H2O)4]). Such one-dimensional chains provide open channels which can accommodate water molecules. Not only accommodated water molecules but also ones coordinated to praseodymium ions were easily removed and absorbed upon heating at 200 °C and exposure of humidity at room temperature, respectively. 相似文献
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Actinomycin D(C1) has been synthesized by a route involving the ester formation between two peptide fragments, (2S,3S)-1-(2-nitro-3-benzyloxy-4-methylbenzoyl)-3-methyl-2-aziridine-carbonyl-D-valylproline t-butyl ester and N-benzyloxycarbonylsarcosyl-N-methylvaline, via a ring-opening reaction of aziridine. Cyclization, followed by reduction and oxidation, gave actinomycin D(C1). The synthetic actinomycin D(C1) was indistinguishable from natural substance with respect to physical properties and biological activity. 相似文献
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Five triterpene glycosides from Oxytropis myriophylla 总被引:1,自引:0,他引:1
Okawa M Yamaguchi R Delger H Tsuchihashi R Nohara T Kinjo J Isoda S Ida Y 《Chemical & pharmaceutical bulletin》2002,50(8):1097-1099
Four new triterpene glycosides: one cycloartane-type glycoside and three azukisapogenol glycosides were isolated together with one known oleanene bisdesmoside from the Mongolian natural medicine, Oxytropis myriophylla. 相似文献
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A phenol-based "end-off" compartmental ligand, 2-[N-[2-(dimethylamino)ethyl]iminomethyl]-6-[N,N-di(2-pyridylmethyl)aminomethyl]-4-methylphenol (HL), having a bidentate arm and a tridentate arm attached to the 2 and 6 positions of the phenolic ring, has afforded the following heterodinuclear M(a)(II)M(b)(II) complexes: [CuM(L)(AcO)(2)]ClO(4) (M = Mn (1), Fe (2), Co (3), Ni (4), Zn (5)), [ZnM(L)(AcO)(2)]ClO(4) (M = Co (6), Ni (7)), and [CuNi(L)(AcO)(NCS)(2)] (8). 1.MeOH (1'), 2.MeOH (2'), 3.MeOH (3'), 4.MeOH (4'), 5.MeOH (5'), and 7.MeOH (7') are isostructural and have a heterodinuclear core bridged by the phenolic oxygen atom of L(-) and two acetate groups. In 1'-5' the Cu(II) is bound to the bidentate arm and has a square-pyramidal geometry with one acetate oxygen at the apical site. The M(II) is bound to the tridentate arm and has a six-coordinate geometry together with two acetate oxygen atoms. In the case of 7' the Zn is bound to the bidentate arm and the Ni is bound to the tridentate arm. 8.2-PrOH (8') has a dinuclear core bridged by the phenolic oxygen atom of L(-) and one acetate group. The Cu bound to the bidentate arm has a square-pyramidal geometry with an isothiocyanate group at the apical site. The Ni bound to the tridentate arm has a six-coordinate geometry with further coordination of an isothiocyanate group. The site specificity of the metal ions is discussed together with the crystal structure of [Cu(4)(L)(2)(AcO)(3)](ClO(4))(3).H(2)O (9) prepared in this work. 相似文献