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1.
通过测定Rf值对比研究了二茂铁亚胺及其环汞化合物的色谱亲和性,发现环汞化合物比未汞化的二茂铁亚胺具有较高Rf值,并用N→Hg分子内配位作用给予解释,分析取代基效应表明,亚胺氮上电子密度越高,Rf值越小,紫外可见光谱表明,环汞化合物人子中存在有N→Hg分子内配位作用,研究了N-Ar环和亚胺碳上的取代基效应对紫外光谱的影响,与N-Ar环上无取代基时相比,π→πCT跃进带的最大吸收波长移动值△λmax和  相似文献   

2.
以人外周血淋巴细胞为标准细胞,用荧光探针吖啶橙(AO)示踪药物和细胞DNA的作用,提出一种用Hadamard变换显微荧光图象分析法初步筛选抗癌药物的新方法,对五晨特异性抗癌药物(CCNSA)的实验结果和药物细胞DNA作用的原理相符,表明此方法地筛选此类抗癌芗,对四种氯代苯甲醛丙氨酸Schiff碱(CA)金属配合物一淋巴细胞DNA作用,研究结果表明:3-CACo、3-CAZn、2-CAK和4-CAD  相似文献   

3.
发现在催化量二茂铁亚胺环钯化合物催化下,芳基氯化汞可在湿和条件下偶联 ,以中等或高的收率生成联芳烃。对于铑盐不能催化偶联的邻位取代苯基氯化汞和 α-基氯化汞,在此体系中亦可发生偶联。以HMPA为溶剂,在x = 0.025(摩尔分 数)化合物1或2催化下与2.0当量氯化锂存在时,得到最好的催化效果。  相似文献   

4.
芳香族有机汞化合物的合成   总被引:1,自引:0,他引:1  
芳香族重氮盐在室温下与氯化汞、亚磷酸二乙酯、氯化铜和丙酮所配成的混合物直接作用,放出氮气生成相应的氯化芳基汞,产率良好,不需要分离重氮盐和氯化汞所生成的复盐.用这个方法合成了31种氯化芳基汞,其中包括五种新化合物.对这个反应的历程进行了初步探讨,它可能是自由基反应.  相似文献   

5.
芳汞基氯化汞和苯硫酚或对甲基硫酚在乙醇中反应合成了两个系列共32种芳汞基芳基硫化合物,其中22种为新化合物。 研究了这些化合物的紫外吸光谱和核磁共针氢谱,所得结果表明,对此两个系列的标题化合物,在△γ~MAX~与Hammett取代基常数 ~P之间有良好的线性关系,但共轭作用未完全通过硫原子贯穿到整个分子。也对取代基~1H NMR的影响进行了研究。  相似文献   

6.
含取代基碲碳菁染料的研究   总被引:1,自引:0,他引:1  
本文报道了含取代基碲碳菁染料(8a~b)的合成方法。4-氯苯胺用等摩尔的乙酸汞、氯化锂及过量的乙酸酐处理可高收率地得到芳基氯化汞(2)。2 在冰乙酸中与等摩尔的四氯化碲回流生成3(内盐)。以水合肼还原3得到化合物4,后者可进一步用硼氢化钠还原并用碘甲烷烷化生成5。化合物6可在不同条件下分别由3、4或5得到。在碘甲烷或碘乙烷作用下,6可以烷基化生成季铵盐(7a~b),后者与原甲酸乙酯在乙酸酐中缩合即生成对称的碲碳菁染料(8a~b)。对染料的可见吸收光谱也进行了讨论。  相似文献   

7.
镍络合物催化条件下2,2'-联吡啶的偶联合成   总被引:2,自引:2,他引:2  
钱延龙  王晨  陶晓春  黄吉玲 《有机化学》2003,23(11):1264-1266
在制备联吡啶的偶联反应中,镍化合物和三苯基膦通常是以化学计量参与反应 。我们在对Tiecco报道的偶联反应进行研究的过程中发现,这一反应可以在催化条 件下进行。这一改进订基于投料顺序的改变,充分利用零价镍当场(in situ)生 成时的高活性。将氯化镍、三苯基膦、2-溴吡啶先溶于DMF中,然后在50 ℃时加入 锌粉,催化偶联生成联吡啶,可以获得满意的收率。同时对三种镍化合物的反应活 性作了比较,以NiCl_2·6H_2O活性最高。  相似文献   

8.
路军  王飞利  白银娟  李万华 《有机化学》2002,22(10):788-792
六水合氯化镍催化下,β-酮酸酯、芳香醛和脲在无水乙醇中进行环化缩合反 应,合成了3,4-二氢嘧啶-2-酮衍生物,改进了Biginelli反应,缩短了反应时 间,且操作简便、产率高。  相似文献   

9.
幼鼠Sertoli细胞分泌一种刺激Leydig细胞合成雄激素的因子   总被引:1,自引:0,他引:1  
本文利用幼鼠Sertoli和Leydig细胞单独或一起培养的方法研究了Sertoli细胞对Leydig细胞的局部影响。结果发现:(1)FSH和LH都能刺激胚胎和幼鼠的睾丸细胞雄激素的生物合成,最大的刺激作用是在生后3—5天;(2)幼鼠Sertoli细胞在FSH作用下分泌一种(些)物质,它能直接(只在幼龄期)或与LH协同刺激Leydig细胞雄激素的合成;(3)Sertoli刺激因子不是类固醇或其他小分子化合物,可能是一种热不稳定的多肽。这种因子可能对幼鼠Leydig细胞向成鼠Leydig细胞的分化和激素合成能力的转化过程中起重要作用。  相似文献   

10.
详细介绍了单细胞微凝胶电泳(SCG)技术的原理和操作过程,并应用该技术研究了氯化镉(CdCl2)对人血淋巴细胞DNA的损伤效应,结果表明,CdCl2能引起细胞DNA迁移长度增加,且呈显著的剂量效应关系,对未处理对照细胞的DNA迁移的原因及SCG实验操作过程中应注意的事项也进行了讨论。  相似文献   

11.
A new system of atomic radii for the elements up to barium inclusive is constructed. Values of the radii are chosen so as the dependence between the dissociation energy of diatomic homonuclear molecules and a depth of atom overlapping is monotonous, and the scatter of data is minimal. The depth of overlapping is calculated as a difference between the sum of atomic radii and an experimental interatomic distance. Conclusions are made that: the radii of free atoms and ions are determined by the value of the electron density equal to 0.01 au; they considerably change in molecules and crystals only as a result of the charge transfer from cation to anion; covalent bonding is well described by the overlapping of free atoms (ions), confined by the surface of the given radius, and its energy depends upon the depth of overlapping of valence electron densities of atoms. A method of overlapping atoms is proposed for the approximate estimation of ionic sizes and charges in bound systems.  相似文献   

12.
We have summarized results of many experimental investigations of the thermodynamics of ionization of H2O(liq.) from 0–300°C and from 1.0 atm to nearly 8000 atm. Results of these investigations (equilibrium constants, enthalpies of ionization, heat capacities, partial molal volumes, and compressibilities) have been used for a number of thermodynamic calculations. It is particularly noteworthy that it is possible to use thermal data from 0–145°C with an equilibrium constant for 25°C in calculating reasonably accurate equilibrium constants for temperatures as high as 300°C. Similarly, it is possible to use volumetric data that refer to 1.0 atm in calculating useful equilibrium constants that apply for pressures as high as 2000 atm.Much of the work reported here was done while the author was on leave at the University of Lethbridge.  相似文献   

13.
The results of recent developments on modelling of supramolecular ordering and physicochemical properties of molecular mixtures have been reviewed. The main attention is paid to the unified approach based on a generalized quasichemical model for a set of thermodynamic, dielectric and optical properties of mixtures, self-organized by specific bonding. Interrelations between thermodynamic, as well as dielectric, and optical properties of liquid mixtures, reflecting different molecular parameters, and the characteristics of quasichemical processes are presented. Applications for thermodynamic functions of mixing, permittivity, coefficients Rayleigh light scattering in molecular mixtures are considered. Data on thermodynamics of aggregation in mixtures have been obtained. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

14.
The standard enthalpies of combustion c H o of aliphatic diacetates1 and aromatic diacetates2 were measured calorimetrically. The enthalpies of vaporization vap H o or sublimation sub H o of1 and2 were obtained from the temperature function of the vapor pressure measured in a flow system. From f H o(g) of1 and2 new values of group increments for the estimation of standard enthalpies of formation of these classes of compounds were derived. The geminal interaction energy between the geminal acyloxy groups shows no anomeric stabilization.Geminal Substituent Effects, Part 12, for part 11 see Ref. 7.  相似文献   

15.
The enthalpies of combustion (ΔH comb) of five primary, secondary, and tertiary alkyl(aryl)arsines in the condensed state were calculated using the equation ΔH comb = −385.8–110.3N, where N is the number of bond-forming electrons. The dependence presented is used for the calculation of the enthalpies of combustion of full esters and amidoesters of arsinous acid of noncyclic and cyclic structures. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1042–1043, May, 2007.  相似文献   

16.
Algorithms are given for evaluating the relative amount of useful information related to a particular parameter which is carried by individual data points and intervals of the variables. The algorithms provide an efficient means of using the information contained in a set of data. Applications to the optimization of weighting in regression methods are described. Several informational and combined informational-statistical types of weighting are studied as a means of improving the accuracy and precision of the parameters obtained by non-linear regression.  相似文献   

17.
微量元素与防病治病   总被引:8,自引:3,他引:8  
介绍了微量元素在防治疾病中的作用及对健康长寿的意义,涉及人体必需微量元素,有害元素,有机锗,微量元素是健康长寿的重要手段以及微量元素与现代文明病。  相似文献   

18.
The protonation of leucoemeraldine in power form and in N-methylpyrrolidinone (NMP) solution by HCIO4 and HBF4 has been studied by x-ray photoelectron spectroscopy (XPS), infrared (IR), and ultraviolet (UV)-visible absorption spectroscopy. In powder form, less than 25% of the amine nitrogens can be protonated in the absence of oxygen. The effects of oxygen on the degree of protonation and the distribution of amine and imine units upon deprotonation of the salt are investigated. The degree of protonation in leuccemeraldine can be increased to about 50% with 3 M HCIO4, similar to that achievable with emeraldine base in powder form. In NMP solution, leucoemeraldine is easily oxidized by dissolved oxygen. Protonation of both leucoemeraldine and emeraldine base in NMP solutions results in metastable species which gradually undergo deprotonation. The resulting products are affected by the O2 content of the solutions. © 1993 John Wiley & Sons, Inc.  相似文献   

19.
Kinetics of oxidation of 1-phenylsemicarbazide (PSC) by peroxydisulphate ion (PDS) have been carried out where by the pseudo first order condition was verified at large excess of PDS concentration. The rate of the reaction was followed spectrophotometrically, The stoichiometry was found to be 1:1 where 1-phenylazoformamide is the oxidation product. The effect of acidity on the rate of oxidation was investigated for different temperatures. The parameters of activation ΔG*, ΔH* and ΔS* were computed for both hydrogen ion depedent and hydrogen ion independent reaction pathes. A free radical mechanism was proposed.  相似文献   

20.
赵梦月  赵建宏 《化学通报》2021,84(2):182-184
本文指出了滴定计算中等物质的量规则的缺陷,并提出了等物质的量定律,将这个反映化学反应客观规律的定律定义为:在氧化还原反应体系中氧化剂与还原剂得与失电子的物质的量相等;在酸碱反应体系中酸与碱得与失质子的物质的量相等;在沉淀反应中阳离子与阴离子所具有电荷的物质的量相等;在络合滴定中金属离子与氨羧络合剂的物质的量相等。等物质的量定律可用下式表达:(i=k)∑(i=1)△n(1/zAi)Ai=(i=P)∑(i=1)△n(1/zBi)Bi。这个定律及其表达式能使复杂的滴定分析计算简单化、规范化。  相似文献   

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