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本文测定了双荧光团化合物2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-二唑及其模型化合物2-甲基-5-联苯基-1,3,4-二唑和2,5-二联苯基-1,3,4-二唑的荧光光谱.对分子内,分子间激基缔合物和激基复合物的形成进行了研究,并对分子构型与形成分子内激基复合物之间关系作了初步探讨.从实验结果得到,亚甲基桥链的碳数为奇数时容易形成分子内激基复合物.  相似文献   

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采用长光程气体池结合傅里叶变换红外光谱仪测得了除草剂2-甲基|4|氯苯氧乙酸(MCPA)与·OH自由基在23 ℃时的反应速率常数为2.67×10-11  cm3/(s*mol), 以此估算了在大气中·OH自由基浓度为 7×105  mol/cm3时, MCPA与·OH自由基反应导致的大气寿命为14.9 h. 结果表明, 在大气环境中MCPA较容易降解, 不会通过大气输送对环境造成广泛和持久性污染.   相似文献   

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Free radicals with reactive chemical properties can fight tumors without causing drug resistance. Reactive oxygen species (ROS) has been widely used for cancer treatment, but regrettably, the common O2 and H2O2 deficiency in tumors sets a severe barrier for sufficient ROS production, leading to unsatisfactory anticancer outcomes. Here, we construct a chlorine radical (.Cl) nano-generator with SiO2-coated upconversion nanoparticles (UCNPs) on the inside and Ag0/AgCl hetero-dots on the outside. Upon near-infrared (NIR) light irradiation, the short-wavelength emission UCNP catalyzes .Cl generation from Ag0/AgCl with no dependence on O2/H2O2. .Cl with strong oxidizing capacity and nucleophilicity can attack biomolecules in cancer cells more effectively than ROS. This .Cl stress treatment will no doubt broaden the family of oxidative stress-induced antitumor strategies by using non-oxygen free radicals, which is significant in the development of new anticancer agents.  相似文献   

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5-(2-Phenylethenyl)indolines, the dehydrogenation of which leads to the formation of the corresponding compounds of the indole series, were obtained from 5-formyl-1-methyl(or benzyl)indolines via the Grignard reaction with benzyl-magnesium chloride and subsequent dehydration. The hormonal activity of the synthesized compounds was studied.See [1] for communication 123.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No, 4, pp. 466–469, April, 1984.  相似文献   

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通过μ-S2Fe2(CO)6的S-S键被Grignard试剂的还原断裂反应及中间物(μ-RS)(μ-XMgS)Fe2(CO)6(2)对氯代乙酸乙酯的亲核取代反应,合成了一系列铁硫原子簇配合物(μ-RS)[μ-EtOC(O)CH2S]Fe2(CO)6(1).1也可由2经三氟醋酸酸解及中月物(μ-RS)(μ-HS)Fe2(CO)6(3)在三乙胺存在下与氯代乙酸乙酯缩合制得.然而前法较后法既操作简便又原料便宜易得.构象分析表明,各配合物一般为ae.ee和ea三种或其中构象体以一定比例存在的混和物.  相似文献   

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3-Chloro-2-polyfluoroalkyl- and 3-chloro-6-nitro-2-polyfluoroalkylchromones were synthesized. These compounds react with N2H4·2HCl on boiling in ethanol to form 4-chloro-3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles.  相似文献   

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While, in general, decamethylzincocene, Zn(C5Me5)2, and other zincocenes, Zn(C5Me4R)2 (R = H, But, SiMe3), react with dialkyl and diaryl derivatives, ZnR'2, to give the half-sandwich compounds (eta5-C5Me4R)ZnR', under certain conditions the reactions of Zn(C5Me5)2 with ZnEt2 or ZnPh2 produce unexpectedly the dizincocene Zn2(eta5-C5Me5)2 (1) in low yields, most likely as a result of the coupling of two (eta5-C5Me5)Zn* radicals. An improved, large scale (ca. 2 g) synthesis of 1 has been achieved by reduction of equimolar mixtures of Zn(C5Me5)2 and ZnCl2 with KH in tetrahydrofuran. The analogous reduction of Zn(C5Me4R)2 (R = H, SiMe3, But) yields only decomposition products, but the isotopically labeled dimetallocene 68Zn2(eta5-C5Me5)2 and the related compound Zn2(eta5-C5Me4Et)2 (2) have been obtained by this procedure. Compound 2 has lower thermal stability than 1, but it has been unequivocally characterized by low-temperature X-ray diffraction studies. As for 1 a combination of structural characterization techniques has provided unambiguous evidence for its formulation as the Zn-Zn bonded dimer Zn2(eta5-C5Me4Et)2, with a short Zn-Zn bond of 2.295(3) A indicative of a strong Zn-Zn bonding interaction. The electronic structure and the bonding properties of 1 and those of related dizincocenes Zn2(eta5-Cp')2 have been studied by DFT methods (B3LYP level), with computed bond distances and angles for dizincocene 1 very similar to the experimental values. The Zn-Zn bond is strong (ca. 62 kcal.mol-1 for 1) and resides in the HOMO-4, that has a contribution of Zn orbitals close to 60%, consisting mostly of the Zn 4s orbitals (more than 96%).  相似文献   

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The transformations of trimethyl(5-methyl-2-furyl)silane and trimethyl(5-methyl-2-furyl)germane were studied upon vapor-phase oxidation by atmospheric oxygen on a V-Mo-Ag-O catalyst. Under these conditions, trimethyl(5-formyl-2-furyl)-silane and trimethyl(5-formyl-2-furyl)germane are formed albeit in only 5–7% yield. This low yield is a consequence of the thermal instability of the starting compounds and the aldehydes formed. The oxidation of 2-methyl-5-tert-butylfuran was studied under comparable conditions. The corresponding aldehyde was obtained in 30% yield. A scheme was proposed for the catalytic oxidation of 5-substituted 2-methylfurans.For Communication 60, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 22–24, January, 1987.  相似文献   

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New Benzyl Complexes of the Lanthanides. Synthesis and Crystal Structures of [(C5Me5)2Y(CH2C6H5)(thf)], [(C5Me5)2Sm(CH2C6H5)2K(thf)2], and [(C5Me5)Gd(CH2C6H5)2(thf)] YBr3 reacts with potassium benzyl and [K(C5Me5)] in THF to give KBr and the monobenzyl compound [(C5Me5)2 · Y(CH2C6H5)(thf)] 1 . The analogous reaction with SmBr3 in THF leads to the polymeric product [(C5Me5)2Sm(CH2C6H5)2 ∞ K(thf)2] 2 , with GdBr3 to [(C5Me5)Gd(CH2C6H5)2(thf)] 3 . The structures of 1–3 were determined by X-ray single crystal structure analysis:
  • Space group P1 , Z = 2, a = 851.2(4) pm, b = 952.7(4) pm, c = 1858.6(8) pm, α = 79.90(4)°, β = 77.35(4)°, γ = 73.30(3)°.
  • Space group P1 , Z = 2, a = 903.3(2) pm, b = 1375.9(3) pm, c = 1801.1(4) pm, α = 100.92(3)°, β = 100.77°, γ = 98.25(3)°.
  • Space group P21/n, Z = 8, a = 1458.2(5) pm, b = 927.8(3) pm, c = 3792.9(15) pm, β = 96.83(3)°.
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Crystal structure of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenolatochloropalladium(II) (PdLCl) has been determined by X-ray diffraction. A crystal of PdLCl was constructed by two structural isomers of PdLCl molecules, which were particularly different in the positions of the carbon atoms at the diethylamino group, having cis-like or trans-like conformation for the carbon atoms. The molecules of PdLCl in the crystal were warped by a steric hindrance of the diethylamino group.  相似文献   

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