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151.
A. I. Yarmolenko S. V. Kukharenko L. N. Novikova V. V. Strelets 《Russian Chemical Bulletin》1995,44(7):1300-1305
It has been shown by cyclic voltammetry in THF within the –90 to 40 °C temperature range that fluorenyl (5-9-R-C13H8)Mn(CO)3 complexes (R=But (3) and Ph (4)) undergo two-electron reduction to form allyl type [(3-9-R-C13H8)Mn(CO)3]2– dianions as final products. At low temperatures complexes3 and4 are reduced in two one-electron steps according to the EEC-scheme. The first step is reversible and corresponds to the formation of 19-radical anions 3–. and 4–.. TheE
0 values for redox pairs3
0/–. and4
0/–. are –1.88 and –1.73 V, respectively. The further reduction of radical anions3
–. and4
–. at more negative potentials is accompanied by fast 5 3 haptocoordination of the fluorenyl ligand to form 18-dianions [(3-9-R-C13H8)Mn(CO)3]2–. These dianions obtained by the reduction of complexes3 and4 by the radical anion of pyrene are stable at –80 °C and are characterized by their IR spectra. At room temperature the 5 3 hapticity change is a fast and reversible process occurring at the step of 19-radical anions3
–. and4
–. and leading to the electron deficient 17-species [(3-9-R-C13H8)Mn(CO)3]–., which are reduced easier than the initial complexes. As a result, complexes3 and4 are reduced to the corresponding dianions [(3-9-R-C13H8)Mn(CO)3]2– at room temperature in one reversible two-electron step according to the ECE-scheme. Reactivities of 19e–-species of the isomeric 5- and 6-fluorenylmanganesetricarbonyl complexes are compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1347–1353, July, 1995.The work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-05209) and the International Science Foundation (Grant No. REV 000). 相似文献
152.
InIII-Phthalocyanines: Synthesis, Properties, and Crystal Structure of Tetra(n-butyl)ammonium-cis-di(nitrito-O,O')phthalocyaninato(2–)indate(III) [In(Cl)Pc2?] reacts with (nBu4N)NO2 in acetone yielding green-blue (nBu4N)cis[In(NO2)2Pc2?], which crystallizes in the monoclinic space group P21/n (No. 14). Both nitrite anions are coordinated as chelating nitrito-O,O'(NO2) ligands to InIII in cis-geometry. Consequently InIII is octa-coordinated within a distorted “quadratic” antiprism and directed towards the Pc2?-ligand. One of the NO2 ligands has equivalent N? O bonds similar to free nitrite, while the other has asymmetric N? O bonds. Both (In,O,N,O) rings are approximately planar with a dihedral angle of 80°. The Pc2? ligand is distorted in an asymmetrically convex manner. Partially overlapping pairs of Pc2? ligands related by an inversion center form double layers, which are separated by layers containing the (nBu4N)+ cations. The cyclic voltammogram shows three electrode processes, which are assigned to the redox pairs: Pc3?/Pc2? (?0.94 V) < InI/InIII (-0.78 V) < Pc2?/Pc? (0.64 V). The UV-VIS-NIR spectra and vibrational spectra are discussed. 相似文献
153.
An intercrosslinked network of cyanate ester (CE)-bismaleimide (BMI) modified epoxy matrix system was made by using epoxy resin, 1,3-dicyanatobenzene and bismaleimide (N,N′-bismaleimido-4,4′-diphenyl methane) with diaminodiphenylmethane as curing agent. BMI-CE-epoxy matrices were characterised using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and heat deflection temperature (HDT) analysis. The matrices, in the form of castings, were characterised for their mechanical properties such as tensile strength, flexural strength and unnotched Izod impact test as per ASTM methods. Mechanical studies indicated that the introduction of cyanate ester into epoxy resin improves the toughness and flexural strength with reduction in tensile strength and glass transition temperature, whereas the incorporation of bismaleimide into epoxy resin influences the mechanical and thermal properties according to its percentage content. DSC thermograms of cyanate ester as well as BMI modified epoxy resin show an unimodal reaction exotherm. Electrical properties were studied as per ASTM method and the morphology of the BMI modified epoxy and CE-epoxy systems were studied by scanning electron microscope. 相似文献
154.
Kaikai Wang Yanli Li Wei Zhang Rongxiang Chen Xueji Ma Mingyue Wang Nan Zhou 《Molecules (Basel, Switzerland)》2022,27(10)
A mild and efficient strategy for the synthesis of tricyclic 1,2,4-oxadiazolines-fused tetrahydro-isoquinolines derivatives via [3 + 2] cycloaddition reaction is reported. The reactions provided the functionalized tricyclic 1,2,4-oxadiazolines in high yields (up to 96%). This protocol is simple and easy to handle. Moreover, a gram-scale experiment further highlights the synthetic utility. The chemical structure of the product was determined by X-ray single-crystal structure analysis. A possible mechanism for this transformation is proposed to explain the reaction process. 相似文献
155.
References: 《理论物理通讯》2007,47(5):905-908
We construct the three-mode cyclic squeezed states and analyze its squeezing property by using the technique of integration within an ordered product of operators and the natural representation of the two-mode squeezing operator in the Einstein-Podolsky-Rosen entangled state basis. 相似文献
156.
157.
电化学DNA生物传感器定量检测根癌农杆菌终止子基因片段 总被引:4,自引:1,他引:3
通过自组装法及共价法固定单链脱氧核糖核酸(ssDNA),制备了电化学DNA生物传感器。将巯基丙酸(MPA)自组装于金电极表面形成单分子膜,再利用1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)的活化作用将ssDNA探针序列固定于金电极表面。将ssDNA修饰的电极与待测溶液中人工合成的转基因食品中常有的根癌农杆菌终止子(NOS)基因片段进行杂交,在[Fe(CN)6]3-/4-溶液中进行循环伏安和电化学阻抗谱扫描,表征ssDNA固定及杂交过程。优化了ssDNA固定条件。待测溶液中DNA浓度在1.0×10-7~1.0×10-10mol/L范围时,其浓度的对数值和ssDNA/Au电极与dsDNA/Au电极峰电流差值的变化值呈线性相关关系,相关系数为0.9822,检出限为8.1×10-11mol/L。 相似文献
158.
159.
Ewa Zaczyska Krzysztof Kaczmarek Janusz Zabrocki Jolanta Artym Micha Zimecki 《Molecules (Basel, Switzerland)》2022,27(11)
The core of Cyclolinopeptide A (CLA, cyclo(LIILVPPFF)), responsible for its high immunosuppressive activity, contains a Pro-Pro-Phe-Phe sequence. A newly synthesized cyclic tetrapeptide, cyclo(Pro-Pro-β3-HoPhe-Phe) (denoted as 4B8M) bearing the active sequence of CLA, was recently shown to exhibit a wide array of anti-inflammatory properties in mouse models. In this investigation, we demonstrate that the peptide significantly inhibits the replication of human adenovirus C serotype 5 (HAdV-5) and Herpes simplex virus type-1 (HSV-1) in epithelial lung cell line A-549, applying Cidofovir and Acyclovir as reference drugs. Based on a previously established mechanism of its action, we propose that the peptide may inhibit virus replication by the induction of PGE2 acting via EP2/EP4 receptors in epithelial cells. In summary, we reveal a new, antiviral property of this anti-inflammatory peptide. 相似文献
160.
Olga Bakulina Anton Bannykh Ekaterina Levashova Mikhail Krasavin 《Molecules (Basel, Switzerland)》2022,27(12)
Screening of a library of novel N-hydroxylactams amenable by the Castagnoli-Cushman reaction identified four lead compounds that facilitated 55Fe transport into P. aeruginosa cells (one of these synthetic siderophores was found to be as efficient at promoting iron uptake as the natural siderophores pyoverdine, pyochelin or enterobactin). Conjugates of the four lead siderophores with ciprofloxacin were tested for antibacterial activity against P. aeruginosa POA1 (wild type) and the ∆pvdF∆pchA mutant strain. The antibacterial activity was found to be pronounced against the ∆pvdF∆pchA mutant strain grown in CAA medium but not for the POA1 strain. This may be indicative of these compounds being ‘Trojan horse’ antibiotics. Further scrutiny of the mechanism of the antibacterial action of the newly developed conjugates is warranted. 相似文献