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1.
合成了16种1,3-双-(介晶基)-1,1,3.3-四甲基二硅氧烷(Ⅱ_(a,b),Ⅲ_(a─g),Ⅲ_j,Ⅳ_(a─f).其化学结构用 ̄1NMR、IR、UV和元素分析表征。通过DSC和偏光显微镜研究了它们的相行为,除Ⅱ_(a,b)、Ⅲ_d和Ⅳ_d外,其余都呈现液晶相变。用X衍射分析研究了1,3-双-(4-甲基偶氮苯氧甲基)-1,1,3,3-四甲基二硅氧烷(Ⅱ_a)的晶体结构。讨论了这些新型硅氧烷化合物的比学结构对液晶相变行为的影响。 相似文献
2.
合成了9种具L-氨基酸衍生物结构的介晶化合物、4种氨基酸衍生物和6种介晶化合物,新化合物的化学结构通过IR、^1HNMR和元素分析证实,并用偏光显微观察和DSC分析研究了其相变行为,结果表明有8种化合物呈现液晶相变。测定了它们的比旋光度,通过X射线射研究了化合物的近晶结构,证明其具铁电性。 相似文献
3.
利用1-芳基-5-甲基-1H-1,2,3-连三唑-4-甲酰氯-,苯并三唑-1-乙酰氯以及5-甲基异恶唑-3-甲酰氯在低温,丙酮-水条件下,分别用7-ACA,7-DCA和7-ADCT反应,制得13种头孢菌素衍生物3a-3i,6a-6b和9a-9b,所有化合物经葡萄糖聚糖凝胶柱层析和离心薄层层析反复精制得纯品,新化合物结构经元素分析,IR,^1HNMR和FAB-MS确认,其中代表物显示出强的抗菌活性。 相似文献
4.
两种环四硅氧烷分别和6种液晶基元化合物(M1-6)反应,合成了6种仅含1个介晶侧基的环四硅氧烷(1-6)。它们的化学结构已由^1HNMR、IR和元素分析证实,借助DSC和偏光显微镜观察研究了12个化合物的相变行为。 相似文献
5.
通过2-取代1,3,4-恶二唑-5-硫醇1a-1f和头孢菌素母体7-ACA反应,制得头孢菌素中间体2a-2f,用氨噻唑肟活性酯3和1-芳基-1H-1,2,3-三唑-4-甲酰氯4a-4e分别和头孢菌素中间体缩合制得头孢菌素新衍生物5a-5b和6a-6h,新化合物的结构经^1H NMR,IR及MS确认,初步体外抗菌结果表明,头孢菌素5a-5b对革兰氏阳性和阴性菌有显著抑制活性,而6a-6h对其则显示出中等程度的抑制活性。 相似文献
6.
标题化合物由BiCl3和乙酰丙酮在HCl(气)/C2H5OH溶剂中通入H2S气体反应而得。晶体属四方晶系,Mt=1130.76,空间群P41212。晶胞参数a=b=8.867(2),c=41.511(4)A;V=3264(1)A^3,Z=4,Dc=2.30gcm^-3,μ(MoKa)=118.607cm^-1,F(000)=2104.晶结构由重原子法求得。最终偏离因子R=0.072。晶体由分立的( 相似文献
7.
通过相转移催化关环反应合成了新的6-取代-2-硫-2-烷(芳)氧-4(2,4-二氯苯基)-4-氢-1,3,2-苯并二氧磷杂环己烷(3a-3g),用结晶法分离得到了7对非对映消旋体,其结构经HNMR、^31PNMR和元素分析确证,化合物3a-A单晶X射线分析表明其构型为(2R,4S;2S,4R),生物活性测定结果表明,化合物3c有良好的杀虫活性,非对映消旋体A和B具有协同杀虫作用。 相似文献
8.
光学活性二醇(1R,2R)-(+)-1,2-二苯基-1,2-乙二醇(Ⅲa)和(2R,3R)-(-)-1,1,4,4-四苯基-2,3-(缩丙酮)-1,4-丁二醇(Ⅲb)分别修饰Ti(OPri)3Cl,再与甲基锂和乙基锂进行烷基化,制备出新的手性有机钛试剂Ⅱa和Ⅱb,然后与苯甲醛进行加成,所得1-苯基乙醇(Ⅳa)和1-苯基丙醇(Ⅳb)的光学收率分别为25~65%e.e.和10~20%e.e.。简单讨论了C2-对称型二醇对立体选择性及反应条件的影响 相似文献
9.
由螺[5.5]十一烷-3-酮与硫脲在碘的存在下反应,生成了4,5-二氢螺[苯并[d]噻唑-6-(7H),1′-环己烷]-2-胺(3),3与溴甲基苯基甲酮在苯中缩合得到相应的酮4a~4c,然后在醇中加热环化生成二氢螺[咪唑并[2,1-b]苯并[d]噻唑]化合物5a~5c。新化合物5a~5c的分子组成及结构经元素分析、1HNMR、13CNMR证实,其中产物5b的分子结构经X-射线衍射晶体分析确认。 相似文献
10.
用X-射线测定了meso-5,10,15,20-四(3,4,5-三甲氧基苯基)卟啉的溶剂(正庚烷)合物(TTOMPP·2C_7H_(16))的晶体结构。实验表明,该化合物(C_(70)H_(86)N_4O_(12))的晶体属三斜晶系,空间群P1,a=8.749(6),b=15.129(6),c=16.449(3),a=60.07(3),β=70.64(4),γ=81.70(5),V=1779.6,M_r=1175.49,Z=1,D_c=1.097g/cm ̄3,μ=0.697cm ̄(-1),F(000)=630。讨论了卟啉环上取代基的电子和立体效应及卟啉与铁(Ⅲ)离子配位后铁(Ⅲ)离于对卟啉结构参数的影响。 相似文献
11.
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 from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997. 相似文献
12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。 相似文献
13.
The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness. 相似文献
14.
Two vanilloids, (5 E)-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
15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992. 相似文献
16.
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, M o, 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 600-700 oC. 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
17.
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。 相似文献
18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides
and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques.
Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated.
Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997. 相似文献
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。 相似文献
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