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《Inorganica chimica acta》1988,150(1):75-80
The title compound, I, crystallizes in the monoclinic space group P21 with cell constants: a = 6.599(3), b = 11.121(2), c = 8.375(1) Å and β = 106.35(2)°; V = 589.74 Å3 and D(calc; Z = 2) = 1.974 g cm−3. The compound is isomorphous and isostructural with its Co analogue. A total of 2982 data were collected over the range of 4° 20 70°; of these, 2537 (independent and with I ⩾ 3σ(I)) were used in the structural analysis. Data were corrected for absorption (μ = 16.6 cm−1) and the relative transmission coefficients ranged from 1.000 to 0.9504. Refinement was carried out for both enantiomeric configurations and the crystal used was found to contain cations with Δ(λδ) absolute configuration. The final R(F) and Rw(F) residuals were, respectively 0.0220 and 0.0239 for (−−−; i.e.Δ(λδ)) and 0.0231 AND 0.0317 FOR (+++; i.e.Λ(δλ)). Thus, the former was selected as correct for our specimen.In the case of I, as well as in the Co derivative [cis-Co(en)2(NO2)2]Cl (II), the conformation of one of the rings is opposite that expected for the lowest energy conformation, which in the current case should be Δ(λλ)).The RhN(NO)2 distances are 2.020(2) and 2.010(2) Å, while the RhN(amine) distances, trans to the NO2 ligands are 2.085(2) and 2.093(1) Å, values distinctly longer than the other two RhN distances (2.064(1) and 2.068(1) Å). The latter are the RhN distances to the terminalNH2 ligands located trans to each other. Thus, we observe a trans effect, which is more pronounced in I than in II, and which is of comparable magnitude to that observed in the case of the trien derivative, [cis-α-Rh(trien)(NO2)2]Cl(III).Parallel with an increase in metalN distances in going from [cis-α-Co(trien)NO2)2]Cl·H2) (IV) to (III) is an increase in the torsional angles of the outer rings (NCCN) of about 10°. Comparison of these parameters in I and II reveal that this change is not so marked for this pair since in I they are −54.9° and 52.8° while in II they are 50.2° and −48.1°; i.e. a change of only 4°. This important difference between trien and en derivatives is caused by the presence of the central five-membered ring, which for compounds III and IV remains largely unchanged, except for the metalN distances.The NO bond lengths are 1.244(3), 1.220)(2), 1.237(2) and 1.211(2) Å, which are similar to those found for the analogous Co isomer. The CN bond lengths are 1.492(3), 1.474(2), 1.486(2) and 1.475(2) Å, while the CC bonds are 1.509(3) and 1.524(3) Å. These values are also comparable with those obtained for the Co isomer and, in fact, the pattern of the bonds is nearly identical in both, including the common feature of having a longer CC bond for the en ring with the conformation opposite that expected.As was the case with the Co analogue, the Cl− anion is associated with the hydrogens of the secondary nitrogen (trans to the −NO2) ligands, the Cl…H7 distance being 2.18(3) Å and the <Cl…H7N2 = 163°. 相似文献
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Krzysztof W. Pankiewicz Kyoichi A. Watanabe 《Nucleosides, nucleotides & nucleic acids》2013,32(5):613-624
Abstract Treatment of ψ-uridine (3) with α-acetoxyisobutyryl chloride in acetonitrile gave, after deprotection, a mixture of four products: 5-(2-chloro-2-deoxy-β-D-arabinofuranosyl)uracil (10a), its 3′-chloro xylo isomer (11a), 2′-chloro-2′-deoxy-ψ-uridine (9a) and 4,2′-anhydro-ψ-uridine (8a). Each component was isolated by column chromatography. Compound 9 was converted to the known 1,3-dimethyl derivative 2 by treatment with DMF-dimethylacetal. Treatment of 10 and 11 with NaOMe/MeOH afforded the same 4,2′-anhydro-C-nucleoside 8. The 1,3-dimethyl analogues of 10 and 11, however, were converted to 2′,3′-anhydro-1,3-dimethyl-ψ-uridine (13) upon base treatment. The epoxide 13 was also prepared in good yield by treatment of 10 and 11 with DMF-dimethylacetal. 相似文献
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Tomoharu Iino Satoshi Shuto Akira Matsuda 《Nucleosides, nucleotides & nucleic acids》2013,32(1-3):169-181
Abstract A synthetic method for (2′S)-2′-C-alkyl-2′-deoxyuridines (9) has been described. Catalytic hydrogenation of 1-[2-C-alkynyl-2-O-methoxalyl-3,5-O-TIPDS-β-D-arabino-pentofuranosyl]uracils (5) gave 1-[2-C-(2-alkyl)-2-O-methoxalyl-3,5-O-TIPDS-β-D-arabino-pentofuranosyl]uracils (4) as a major product, which were then subjected to the radical deoxygenation, affording (2′S)-2′-alkyl-2′-deoxy-3′,5′-O-TIPDS-uridines (7) along with a small amount of their 2′R epimers. 相似文献
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Hiroshi Okada 《Plant Systematics and Evolution》1984,148(1-2):89-102
Both diploid and tetraploid experimental interspecific hybrids betweenRanunculus silerifolius (2x) andR. chinensis (2x) exhibit normal bivalent pairing. However, microspores of diploid hybrids do not undergo mitosis and their pollen grains are highly sterile, whereas tetraploid hybrids form good pollen grains after microspore division. Evidence is forwarded for the assumption thatR. cantoniensis (4x) has originated by hybridization between these two diploid parental species and by polyploidization of the diploid hybrids. Parallelisms between the different karyotypes ofR. cantoniensis (4x) andR. silerifolius (2x) suggest that the former is a species of polyphyletic origin. 相似文献
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《Inorganica chimica acta》1986,111(1):39-43
Redox properties of the ion [Fe(CN)4NO]2− were studied electrochemically both in non-aqueous and aqueous media in the absence of free cyanide ions. It was found that while the reduction proceeds smoothly the oxidation is not observed at the electrode in the attainable potential range, and can be achieved only by Br2 oxidation taking place as oxidative addition. Aspects of the redox reactivity are discussed and the overall scheme of reactions of the tetracyanonitrosylferrate(2−) and derived species is given. 相似文献
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《Inorganica chimica acta》1988,147(2):211-216
The main emphasis in the study has been the investigation of the kinetics of the stepwise reactions of [Co(tren)C2O4]+ ion [tren = 2,2’,2”-triaminotriethylamine, N(CH2CH2NH2)3] in both dilute and concentrated acids, as well as the characterization in solution of some new Co(III) tren complexes. The aquation reaction was conducted in 1.0 M HClO4 solution under various conditions. Protonation of a carbonyl oxygen in the complex appeared to increase the lability of the Co—O moiety, leading to a unidentate oxalate ligand. The stepwise anation of [Co- (tren)C2O4]+ to [Co(tren)Cl2]+ in concentrated HCl was also followed. Both systems react by a dissociative reaction mechanism. 相似文献
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Kathirvelu Baskar Anbalagan Santhosh Kumar Gnanaprakasam Antony Raj Soosaimanickam Maria Packiam Savarimuthu Ignacimuthu 《Archives Of Phytopathology And Plant Protection》2013,46(5):400-411
Indiscriminate use of synthetic pesticides to control the pests causes negative effects on non-target organisms. Some of the chemicals under B and C categories are carcinogenic to humans. The present study was aimed to assess the antifeedant, larvicidal and pupicidal activities of Hygrophila schulii (syn. H. auriculata) and Blumea mollis against Helicoverpa armigera. Maximum antifeedant activity of 70.01% was observed in ethyl acetate extract of H. schulii at 5.0% concentration with LC50 value of 2.0%. B. mollis ethyl acetate extract at 5.0% concentration showed antifeedant activity of 35.40% with LC50 value of 8.38%. The data for antifeedant activity showed homogeneity of variances in Levene Statistics and normality in Shapiro–Wilk test. Ethyl acetate extract of H. schulii at 5.0% concentration showed 68.66% larvicidal activity with LC50 value of 2.97%. It also showed 73.33% pupicidal activity and was statistically significant from other treatments. No pupicidal activity was observed in ethyl acetate extract of B. mollis. All concentrations of ethyl acetate extract of H. schulii showed promising biological activities which differed statistically from other treatments. Ethyl acetate extract of H. schulii could be used to develop new botanical formulations to manage agricultural pests. 相似文献
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George D. Koufos 《Pal?ontologische Zeitschrift》1987,61(3-4):339-358
The hipparions of the locality Prochoma-1 of the lower Axios valley (Macedonia, Greece) are studied. Two species can be distinguished, the medium-sizedH. dietrichi (Wehrli) and the smallsizedH. macedonicum Koufos. The presence of the large-sizedH. proboscideum Studer, is possible. The locality dates back to Latest Vallesian-Early Turolian as it is proved by some morphological characteristics of hipparions, by the faunal composition and by its similarity with the faunas of the other localities of the lower Axios valley. 相似文献
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《Bioscience, biotechnology, and biochemistry》2013,77(7):1347-1348
A novel dimer of an inositol glycoside was isolated from the mycelial extracts of Streptomyces sp. AJ 9463. Its structure was assigned as a disulfide of 2-(N-acetyl-L-cysteinyl)amido-2-deoxy-α-D-glucopyranosyl-(1→1)-1D-myo-inositol (1). 相似文献
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Limeira-de-Oliveira F 《Neotropical Entomology》2008,37(4):426-428
Esenbeckia (Esenbeckia) rafaeli, sp.nov. is described and figured from nine specimens collected in Carolina, state of Maranh?o, Brazil. The new species is compared with the species Esenbeckia (Esenbeckia) laticlava Wilkerson & Fairchild, 1983; Esenbeckia (Esenbeckia) bitriangulata Lutz & Castro, 1935 e Esenbeckia (Esenbeckia) enderleini Kr?ber, 1931. 相似文献
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Polynucleotides. LII1 Synthesis and properties of poly(2′-deoxy-2′-fluoroadenylic acid) 总被引:8,自引:8,他引:0
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2′-Deoxy-2′-fluoroadenosine was chemically transformed to its 5′-diphosphate and polymerized with polynucleotide phosphorylase to give poly(2′-deoxy-2′-fluoroadenylic acid) [poly(Af)]. Polymerization proceeded smoothly as in the case of poly(A) and the yield of the polymerization was 55%. The UV absorption spectra of poly(Af) closely resembled those of poly(A) and the hypochromicity was 32% at pH 7.0. The CD profile at 25° and neutrality showed similar pattern to that of other poly(2′-deoxy-2′-halogenoadenylic acids) with somewhat larger [θ] values both in the positive and negative maxima. Acid titration of poly(Af) showed a transition point at pH 5.2 and the Tm of the acid form was 37° which was significantly lower than that of poly(A), but similar to that of poly(2′-azido-2′-deoxyadenylic acid). Poly(Af) formed 1:1 and 1:2 complexes with poly-(U) having Tm of 49° and 62° at 0.04M and 0.15M Na+ concentration, respectively. Poly(Af) also formed a 1:2 complex with poly(I) and its Tm was 36° at 0.05M Na+ concentration. These data showed that poly(Af) has rather similar properties to those of poly(A), but not to poly(dA). 相似文献
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《Inorganica chimica acta》1986,115(1):L19-L21