4,4＇-二硝基二苯乙烷(烯)的合成

二硝基二苯乙烯;硝基甲苯;氧化二聚反应;4;4＇-二硝基二苯乙烷(烯)的合成     

The synthesis and antilipidperoxidation activity of 4,4-diarylbutylamines and 4,4-diarylbutanamides

A series of 4,4-diarylbutylamine and 4,4-diarylbutanamide derivatives has been synthesized and evaluated for their antilipidperoxidation (ALP) activity and acute toxicity (LD50). Some of them were found to have significant ALP activity.     

Mesomorphic phase transitions of 4,4'-dialkyloxyquaterphenyls and dialkyl quaterphenyl-4,4'-dicarboxylates

The mesogenicities of 4,4'-dialkyloxyquaterphenyls (DAQP) and dialkyl quaterphenyl-4,4'-dicarboxylates (DCQP) were studied by differential scanning calorimetry, optical microscopy and miscibility tests. The DAQP homologues, for which the number of carbon atoms in the alkyloxy group (n) is 1-9, showed a S_A phase, and the higher homologues (n = 9-18) showed a Sc phase. The propyl, butyl and pentyl esters of DCQP showed a S_A phase, and the octyl and dodecyl esters showed S_A and Sc phases. The isopropyl, isobutyl, 2-ethylhexyl and cyclohexyl esters showed a Sc phase and the branching of the alkyl group strikingly lowered the mesophase thermal stabilities.     

Syntheses and Crystal Structures of 4,4‘—Diformyl—diphenoxyethane and 4,4’,4‘’—Triformyl—triphenoxytriethylamine

Two title compounds, 4,4'-diformyl-diphenoxyethane (compound 1, C16H14O4)and 4,4',4'-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris2-chloroethylamine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ', = 105.823(6)o, V = 675.7(2)'3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, (MoK = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ', = 99.505(1)°, V = 2383.5(3) '3, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, (MoK = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 dialdehyde is located at the crystallographic inversion center nearby the midpoint of C8-C8A single bond. The three chains in the molecule of compound 2 trialdehyde are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.     

Heat capacity and thermodynamic functions of 4,4′-dimethylbiphenyl and 4,4′-di-tert-butylbiphenyl

The heat capacity (C _{p m} ) of 4,4′-dimethylbiphenyl and 4,4′-di-tert-butylbiphenyl in the temperature range of 8—373 K was measured by low-temperat ure adiabatic calorimetry, and thermodynamic characteristics of the solid-phase transitions of 4,4′-d i-tert-butylbiphenyl were determined. Temperatures, enthalpies, entropies of melting, and the purity of the samples of the tested substances were determined by means of differential scanning calorimetry. The main thermodynamic functions of the substances in the condensed state at 298 K were calculated.     

4,4＇-二苯氧基二苯砜、4,4＇-二苯氧基二苯酮、对苯二甲酰氯三元共聚物的合成

聚醚酮醚酮酮;4;4＇-二苯氧基二苯砜、4;4＇-二苯氧基二苯酮、对苯二甲酰氯三元共聚物的合成;聚醚砜醚酮酮;低温溶液浓缩聚     

A Convenient Synthesis of 4,4′-Dimethylaminodiphenyl Diselenide and 4,4′-Dinitrodiphenyl Diselenide

A simple, rapid and efficient synthesis of 4,4′-dimethylamino-diphenyl diselenide 1 and 4,4′-dinitrodiphenyl diselenide 2 is described. The method consists of the reductive cleavage of the Se-CN linkage in the corresponding aryl selenocyanates by sodium borohydride followed by air oxidation of the resulting seleno-lates. The diselenides 1 and 2 are readily obtained in a state of high purity, in 89 and 80% yield, respectively.     

Pressure dependence of the low-frequency raman spectra of 4,4'-difluorobenzophenone and 4,4'-dibromobenzophenone

The low-frequency Raman spectra as a function of hydrostatic pressure for 4,4'-difluorobenzophenone and 4,4'-dibromobenzophenone are presented. The change observed in some of the Raman bands suggests that the pressure induces changes in the crystal structure.     

Reduction of 4,4′-Stilbenequinone and 4,4′-Diphenoquinone upon Reaction with Photogenerated Radicals

The properties of 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone (StQ) were studied by photochemical means. Acetone, acetophenone or benzophenone was photolyzed in the presence of both StQ and a donor, such as alcohols or triethylamine. This initiated reaction of a ketyl radical with StQ to form a semiquinone radical and eventually induce a permanent bleaching due to conversion of StQ to 4,4′-dihydroxystilbene (StQH₂). The quantum yield of conversion of StQ to StQH₂ increases with the donor concentration. Similar effects were found for the ketone-sensitized radical-induced conversions of the analogous diphenoquinone to the reduction product, diphenol.     

Convenient method to access new 4,4-dialkoxy- and 4,4-diaryloxy-diaza-s-indacene dyes: Synthesis and spectroscopic evaluation

A straightforward method for the synthesis of original 4,4-dialkoxy- or 4,4-diaryloxy-diaza-s-indacenes (BODIPY) derivatives obtained by treatment of BODIPY 1 with various alcohols in the presence of AlCl3 is described. The novel compounds are characterized by spectroscopic properties similar to those of the parent BODIPY 1, absorption and emission spectra with similar band shapes, high molar absorption coefficients (epsilon lambda max approximately 80,000 M(-1) cm(-1)), and for most of them high fluorescence quantum yields (Phi exp from 0.52 to 0.71). Among all of the new compounds synthesized, the dye 2 h exhibits higher fluorescence quantum yield (0.71) and lifetime (4.09 ns) than compound 1 and a good chemical stability toward conditions compatible with biological cell-based assays.     

4,4′-二羟基二苯砜二钾盐与4,4′-二氯二苯砜的溶液缩聚

对4,4′-二羟基二苯砜二钾盐与4,4′-二氯二苯砜的溶液缩聚,进行了较系统的研究:选择了环丁砜为聚合介质,二甲苯作带水剂;研究了缩聚温度,时间及固含量的影响;讨论了单体配比及碱用量对双酚S配比变化对聚合物分子量的影响,在成盐时添加K_2CO_3可减少产物分子量的波动范围。讨论了影响聚芳砜在加工温度下的热稳定性的因素,并建议了控制后处理过程的方法,最后列出了全对位聚芳砜的主要性能。     

4,4'-二氨基三苯胺的合成与纯化

以苯胺和对硝基氯苯为原料,K2CO3作催化剂,合成出了中间产物4,4'-二硝基三苯胺(DNTPA).将中间产物用10%(质量分数)的Pd/C催化剂加氢催化还原,得到纯度为96.6%的目标产物4,4'-二氨基三苯胺(DATPA),合成总产率为38%.与其它方法相比,该方法原料便宜易得,纯度很高,产物可作为反应的单体原料.