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合成了双水杨醛缩1,10-癸二胺Sch iff碱配体(C24H32N2O2,以L表示)与稀土Ln3+的15种新的固体配合物[LnL(NO3)3].nH2O(Ln=La,Ce,Pr,Nd,Sm,Eu,n=0;Ln=Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y,n=1).利用元素分析、摩尔电导、红外光谱、热分析等方法进行表征.中心金属离子Ln3+与Sch iff碱配体中的酚羟基氧以及硝酸根中的氧发生配位,配位数为8. 相似文献
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合成了香兰素缩赖氨酸希夫碱配体(HL)和15种香兰素缩赖氨酸希夫碱的稀土配合物REL(NO3)2.3H2O(RE=Y,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu),并通过元素分析、摩尔电导、热重分析、红外光谱、紫外光谱、核磁共振方法对配合物的组成和结构进行了表征。采用紫外光谱和荧光光谱方法初步研究了Nd,Tb,Yb,Lu这4种希夫碱配合物与DNA的相互作用,实验结果显示,随着DNA的加入,配合物在280 nm处的紫外吸收峰不断增强,同时配合物在418 nm左右的荧光发射峰随DNA浓度的增大均逐渐减小,说明配合物和DNA是以静电模式结合。 相似文献
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1-苯基-3-甲基-七氟丁酰吡唑酮-5(PMHFP)及邻菲咯啉(phen)希土混配配合物的合成及性质研究 总被引:1,自引:1,他引:1
本文在乙醇中合成了PMHFP及phen与希土离子的三元配合物Ln(PMHFP)3·phen(Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y).通过化学分析,元素分析及电导分析确定了配合物的组成;研究了配合物的紫外、红光光谱;借助于差热-热重分析仪研究了所有配合物的挥发性质,测定了它们各自的起始挥发温度,探讨了用于希土分析的可能性. 相似文献
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稀土冠醚配合物的研究XV. 稀土硝酸盐与臂型冠醚配合物的合成 和性质研究 总被引:4,自引:0,他引:4
本工作以6-羟基-2,3,9,10-二苯并-1,4,8,11,14-五氧杂-环十六-2,9-二烯(1)及其衍生物(2,3和4)为配体,在乙腈中合成了十八种新的稀土硝酸盐配合物。其中羧酸冠醚4与稀土硝酸盐[Ln(NO~3)~3]分别形成2:1型(Ln=La,Ce,Pr,Nd)、4:3型(Ln=Sm)和3:4型(Ln=Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)配合物;冠醚1与La(NO~3)~3形成1:1型配合物;冠醚2,3与La(NO~3)~3均形成2:1型配合物。对所得配合物进行了元素分析、紫外光谱、红外光谱、^1H核磁共振、X射线光电子能谱等性质研究。对臂型冠醚中边臂的配位作用进行了初步讨论。 相似文献
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本工作以6-羟基-2,3,9,10-二苯并-1,4,8,11,14-五氧杂-环十六-2,9-二烯(1)及其衍生物(2,3和4)为配体,在乙腈中合成了十八种新的稀土硝酸盐配合物.其中羧酸冠醚4与稀土硝酸盐[Ln(NO_3)_3]分别形成2∶1型(Ln=La,Ce,Pr,Nd)、4∶3型(Ln=Sm)和3∶4型(Ln=Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)配合物;冠醚1与La(NO_3)_3形成1∶1型配合物;冠醚2,3与La(NO_3)_3均形成2∶1型配合物.对所得配合物进行了元素分析、紫外光谱、红外光谱、~1H核磁共振、X射线光电子能谱等性质研究.对臂型冠醚中边臂的配位作用进行了初步讨论. 相似文献
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本文利用非等温DSC曲线对十二种镧系元素异硫氰酸盐与苄胺形成的配合物Ln(NCS)_2.4C_6H_5CH_2NH_2(Ln=La、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb)进行了非等温动力学研究,并运用积分法和微分法进行了分析,推断了它们的热分解反应机理函数,当Ln=La、Pr、Nd、Sm、Eu、Gd时,配合物的热分解动力学方程式da/dt=A·e~(-E/RT·3)(1-α)~(2/3);当Ln=Tb、Dy、Ho、Er、Tm、Yb时,则为dα/dt=A·e~(-E/RT·)(1-α),呈现“钆断”现象.此外还得到了该系列配合物的热分解反应动力学补偿效应表达式. 相似文献
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本文报告了薄层色谱法分离稀土元素的最佳条件。当选择N_(263)正辛醇-石油醚-浓盐酸展开剂的体积比为2.0:6.0:30.0:1.2时,可将La、Ce、Pr,Nd、Sm(或Eu、Gd)完全分离:当体积比为2.0:10.0:30.0:1.0时,Tb,Dy(或Ho),Er、Tm、Yb、Lu可获得满意分离;而体积比为2.0:7.0:30.0:1.0时,La、Ce、Pr、Nd、Sm(或Eu、Gd)、Tb(或Dy、Ho)、Er、Tm、Yb、Lu经一次展开可获得完全分离。用三溴偶氮胂作显色剂,检测下限可达0.01μg。 相似文献
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The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted
indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator
model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was
established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing
analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
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Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared. 相似文献
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Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position. 相似文献
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The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations
were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples
were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of
hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the
best fitting experimental data.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6. 相似文献
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Stepkowska E. T. Perez-Rodriguez J. L. Jimenez de Haro M. C. Sayagues M. J. 《Journal of Thermal Analysis and Calorimetry》2002,69(1):187-204
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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微量钙的测定方法研究进展 总被引:5,自引:0,他引:5
介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。 相似文献