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排序方式: 共有2116条查询结果,搜索用时 19 毫秒
71.
Takahito Itoh Hiroki Saitoh Shouji Iwatsuki 《Journal of polymer science. Part A, Polymer chemistry》1995,33(10):1589-1596
1,1′-Dialkylferrocene-3,3′-dicarbaldehydes ( 1a–c ) with long alkyl chains such as ethyl, hexyl, and dodecyl groups were prepared in 13–25% yield via three-step reactions. The titanium-induced dicarbonyl-coupling reaction of 1a–c gave poly(1,1′-dialkyl-3,3′-ferrocenylenevi-nylene)s ( 2a–c ) in quantitative yields, which were the molecular weights of 3000–10,000 and highly soluble in chloroform, benzene, and hexane. The electrical conductivity and the third-order nonlinear optical susceptibility for poly(1,1′-dihexyl-3,3′-ferrocenylenevinylene) ( 2b ) were estimated to be 1 × 10?2 S/cm on doping with iodine and 1–4 × 10?12 esu at a wavelength of 1–2.4 μm, respectively. © 1995 John Wiley & Sons, Inc. 相似文献
72.
Drochioiu G 《Talanta》2002,56(6):1163-1165
A very simple, accurate, fast, selective and sensitive assay of cyanide based on its reaction with 2,2-dihydroxy-l,3-indanedione at basic pH is proposed. As little as 0.01 μg ml−1 of cyanide can be determined. The molar absorptivity may reach 5.1–8.0×104 l mol−1 cm−1 depending on the reaction conditions. Thus, 1 ml of sample solution is mixed with 500 μl of 5 mg ml−1 solution of 2,2-dihydroxy-1,3-indanedione monohydrate in 2% sodium carbonate. The absorbance of the purple color is measured at 510 nm in 1-cm glass cuvettes, 10–15 min after mixing the reagents. The procedure could also be used to identify free CN− in natural waters and hydrocyanic acid in the environment. 相似文献
73.
Addition of dimethyl phosphite to racemic 3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocene-2-carboxaldehyde gives almost exclusively one diastereomer of the corresponding α-hydroxyphosphonate (d.r. ?96:4). Its absolute configuration (S, Rp)-(R, Sp) was established by X-ray diffraction. 相似文献
74.
Compound [Zn(phen)3][BDA] (1) (BDA=6,6′-dibromo-2,2′-dimethoxy-1,1′-binaphthylene-4,4′-disulfonate, phen= 1,10-phenanthroline) composes of the anion part (racemic-(R,S)-6,6′-dibromo-2,2′-dimethoxy-1,1′-binaphthylene-4,4′-disulfonate ) and the cation part which consists of a racemic octahedrally coordinated zinc center defined six nitrogen atoms from three phen rings to form an inorganic chirality that can be resolution by chiral organic ligand, the 3D framework was formed through the strong H-bonding interaction between sulfonate and water. CCDC: 277924. 相似文献
75.
Ivica Cepanec Mladen Litvi? Josipa Udikovi? Ivan Pogoreli? Marija Lovri? 《Tetrahedron》2007,63(25):5614-5621
Copper(I) triflate acts as an efficient stoichiometric reagent for the homo-coupling of aryldiazonium salts bearing electron-withdrawing group(s), to yield symmetrical biaryls in acetonitrile under mild reaction conditions. Aryldiazonium salts bearing electron-donating groups undergo the reaction by using catalytic amounts of a copper complex prepared in situ from copper(II) triflate and 2,2′-bipyridine with metallic copper as an ultimate reductant. 相似文献
76.
Synthesis, EPR and X-Ray Structure of mer-Trichloro(2,2′-bipyridine)nitridotechnetium(VI) — a new Technetium(VI) Nitrido Complex mer-Trichloro(2,2′-bipyridine)nitridotechnetium(VI) has been prepared by the reaction of (NBu4)[TcNCl4] with 2,2′-bipyridine in acetonitrile, whereas the same procedure gives in methanol the technetium(V) cation [TcNCl(bipy)2]+. The EPR spectrum of [TcNCl3(bipy)] suggests a meridional coordination of the three chloro ligands. [TcNCl3(bipy)] crystallizes monoclinic in the space group P21/n; a = 8.572(1), b = 15.462(1), c = 10.110(1) Å, β = 104.21(1)°, Z = 4. The R value converged at 0.034 on the basis of 3 040 reflections. The technetium atom is distorted octahedrally coordinated with the chloro ligands meridionally cis with respect to the nitrido nitrogen. The Tc? N(1) bond length is 1.669(4) Å, and the Tc? N(3) bond (2.371(4) Å) is significantly lengthened due to the structural trans labilizing influence of the “N3?” ligand. 相似文献
77.
Pavel V. Pasternak 《Journal of fluorine chemistry》2004,125(12):1853-1868
A new CF2X-analogue of 1,1-bis(trifluoromethyl)-2,2-dicyanoethylene (X = P(O)(OEt)2), diethyl (1,1-difluoro-3,3-dicyano-2-trifluoromethylallyl)phosphonate, has been synthesized from diethoxyphosphoryl pentafluoroacetone 1. A similar phosphoryl analogue of ethyl 3,3-dicyano-2-trifluoromethylacrylate, ethyl 3,3-dicyano-2-[(diethoxyphosphoryl)difluoromethyl]acrylate, has been obtained from ethyl 3-(diethoxyphosphoryl)-3,3-difluoro-2-oxopropionate 2. By heterocyclization of these new ethylenes with 3-methyl-2-pyrazoline-5-ones, 3(5)-aminopyrazoles, dimedone, 2-aminopyridines, 1-aryl-3-methyl-5-aminopyrazoles, 1,3,3-trimethylisoquinolines, as well as by condensation with anilines and ketones, the difluoromethylphosphonate-substituted derivatives of 1,4-dihydropyrano[2,3-c]pyrazole, 4,5-dihydropyrazolo[1,5-a]pyrimidine, 5,6,7,8-tetrahydro-4H-chromene, 2H-pyrido[1,2-a]pyrimidine, 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine, 1,4-dihydropyridine, 4,5,6,7-tetrahydro-1H-[1]pyrindine, 1,4,5,6,7,8-hexahydroquinoline, and 6,7-dihydro-2H-pyrido[2,1-a]isoquinoline have been obtained in one stage. 相似文献
78.
Chun Li 《Tetrahedron》2004,60(37):8037-8041
It has been confirmed that octasulfonatocalix[8]arene (Calx-S8) and tris(2,2′-bipyridine)ruthenium (II) (Ru(bpy)32+) can form a stable host-guest complex in aqueous solution. The binding constant for 1:1 [Calx-S88−·Ru(bpy)32+]6− complex formation was estimated to be (2.4±0.8)×104 dm3 mol−1 by fluorescence titration, which indicates that the [Calx-S88−·Ru(bpy)32+]6− complex is the main species in 1:1 molar ratio aqueous solution of Calx-S8 and Ru(bpy)32+. In situ UV-Vis spectroscopic measurements indicated that Ru(bpy)32+ complexes can be readily deposited onto ITO electrode through electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) using [Calx-S88−·Ru(bpy)32+]6− host-guest complex as a dopant anion owing to the electrostatic interaction between the cationic conductive polymer and the anionic host-guest complex. The loading degree of the composite film with Ru(bpy)32+ can be determined by Lambert-Beer law modified for the two-dimensional concentration. The obtained composite film showed good photoelectric conversion properties in response to visible light irradiation. This is a novel photocurrent generation system in which the photoexcited state energy is efficiently collected by the conductive polymeric layer. 相似文献
79.
Sarah Fakih Wing Chau Tung Dirk Eierhoff Christian Mock Bernt Krebs 《无机化学与普通化学杂志》2005,631(8):1397-1402
In modern cancer therapy the clinical application of platinum‐based drugs is more and more limited by the occurrence of intrinsic or acquired resistances. In this context the potential use of dinuclear platinum complexes in chemotherapy is increasingly relevant. The novel complexes Pd(Bzdpa)Cl2, Pd2(C4H8(dpa)2)Cl4, and Pt2(C4H8(dpa)2)Cl4 allow a direct comparison of mono‐ and dinuclear palladium and platinum complexes respectively deriving from a 2,2′‐dipyridylamine (Hdpa) ligand system. They were characterized by single crystal X‐ray analysis as well as infrared spectroscopy and elemental analysis. The cisplatin analogous mononuclear palladium complex Pd(Bzdpa)Cl2 ( 1 ) (Bzdpa: (2,2′‐dipyridylbenzyl)amine) belongs to a range of 2,2′‐dipyridylamine‐based compounds which were extensively studied in our laboratories. 1 crystallizes in the orthorhombic space group Pna21 with a = 13.722(3), b = 13.457(3), c = 9.483(2), V = 1751.1(6) Å3, and Z = 4. The metal binding motif of 1 was expanded by a flexible butyl‐linker to form the tetradentate C4H8(dpa)2 ligand. The resulting isotypic dinuclear complexes Pd2(C4H8(dpa)2)Cl4·2CH3CN ( 2 ) and Pt2(C4H8(dpa)2)Cl4·2CH3CN ( 3 ) crystallize in the triclinic space group with a = 7.8427(2), b = 8.7940(2), c = 11.7645 (3), α = 79.219(2)°, β = 84.033(2)°, γ = 87.744(2)°, V = 792.58(3) Å3 ( 2 ) and a = 7.831(5), b = 8.814(5), c = 11.817(5), α = 79.271(5)°, β = 83.571(5)°, γ = 88.063(5)°, V = 796.3(8) Å3 ( 3 ), both with one centrosymmetrical molecule in the unit cell. 相似文献
80.
Ren Yan-Wei Dang Li-Long Li Jun Gao Wei-wei Zhang Feng-Xing 《Journal of Structural Chemistry》2005,46(2):352-357
A novel one-dimensional (1D) chain coordination polymer [Mn2(2,2′-dipha)2(phen)]n has been synthesized by hydrothermal reaction, and characterized by elemental analysis, IR spectroscopy, TGA, and X-ray diffraction. Orange crystals crystallized in the monoclinic system, space group C2/c with a = 19.393(7) Å, b = 19.183(7) Å, c = 19.729(7) Å, β = 90.826(6)°, V = 7338(5) Å3, Z = 8. In the crystal structure, one manganese atom is six-coordinated with four carboxylate oxygen atoms from one pentadentate 2,2′-dipha ligand and two tetradentate 2,2′-dipha ligands, and with two nitrogen atoms of one phen ligand, giving a slightly distorted octahedral geometry. The other manganese atom is five-coordinated with five oxygen atoms from two tetradentate 2,2′-dipha ligands and two pentadentate 2,2′-dipha ligands and has a trigonal bipyramidal environment. The TGA curve shows that the compound is stable below 310°. 相似文献