首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
《Fluid Phase Equilibria》2004,218(2):247-260
Density (ρ) and viscosity (η) values of the binary mixtures of phenetole+1-pentanol, + 1-hexanol, + 1-heptanol, + 1-octanol, + 1-nonanol, and + 1-decanol over the entire range of mole fraction at 293.15, 298.15, 308.15, and 318.15 K have been measured at atmospheric pressure. The excess molar volume (VE), viscosity deviations (Δη), and excess Gibbs energy of activation (G*E) have been calculated from the experimental measurements. These results were fitted to Redlich and Kister polynomial equation to estimate the binary interaction parameters. The viscosity data were correlated with equations of Grunberg and Nissan, Hind et al., Frenkel, and McAllister. While the excess molar volumes of phenetole+1-pentanol, + 1-hexanol are positive, the remaining binary mixtures are negative. The viscosity deviations and excess Gibbs energy of activation are negative for all investigated systems. As the chain length of 1-alkanols increases, both viscosity deviations and excess molar volume values decrease while excess Gibbs energy of activation value increase. The temperature has no effect on excess molar volume, slight effect on excess Gibbs energy of activation, and significant effect on viscosity deviations. The calculated functions have been used to explain the intermolecular interaction between the mixing components.  相似文献   

2.
Novel lithiated carbanions derived from ethyl glycosyl- and diglycosyl methylphosphonates were used in a direct and convenient synthesis of P1,P2-diglycosyl, P1,P1,P2-triglycosyl, and P1,P1,P2,P2-tetraribosyl methylenediphosphonates involving a one-pot methylidenediphosphonylation of sugars.  相似文献   

3.
In the course of our investigations on the development of cardiovascular agents, 3-butyl-2-[2′-(2H-tetrazol-5-yl)bipheny]-4-yl]methyl-2H-1, 2, 4-benzothiadiazine 1, 1-dioxide ( 2 ) was considered as a potential angiotensin II antagonist on the basis of bioisosteric replacement of the quinazoline ring of compound 1 with a 1, 2, 4-benzothiadiazine 1, 1-dioxide ring system. Alkylation of 6 with 4 afforded 7 and 8 in 24% and 28% yields, respectively. An attempt to remove the trityl group of compounds 7 and 8 under acidic condition gave the ring opened products 9 and 11 in 28% and 36% yields, respectively. However, compounds 2 and 10 were obtained in 46% and 85% yields when compounds 7 and 8 were refluxed in methanol. Preliminary assays of compounds 9 and 11 against angiotensin II receptors revealed weak activity with IC50 values of 3.6 μM and 5.4 μM, respectively. Compound 10 (IC50 = 87 nM) exhibited stronger binding affinity than compound 2 (IC50 = 750 nM).  相似文献   

4.
The syntheses of 1, 2-annelated 1, 4-benzodiazepines (IV, Y = N) and 4, 1-benzoxazepines (IV, Y = 0) are described (Scheme 1). The key step is a nucleophilic aromatic substitution of 2-substituted piperazines (II, Z = N? CH3), piperidines (II, Z = CH2) or pyrrolidines (II, Z= (CH2)0) with activated aryl halides (I).  相似文献   

5.
1,1-Di-p-methoxyphenyl-2, 2-dinitroethylene reacts with 1-benzyl-1, 4-dihydronicotinamide (BNAH) in deaerated acetonitrile to give 1,1-di-p-methoxyphenyl-2, 2-dinitroethane,while 1,1-di-O-methoxyphenyl-2, 2-dinitroethylene fails to react with BNAH under the same conditions, which provides evidence for a concerted electron-hydrogen atom transfer mechanism.  相似文献   

6.
Reaction of o-dichlorobenzene with dimethylmethoxychlorosilane and sodium leads to the isolation of dimethyl(o-chlorophenyl) methoxysilane, o-bis(bimethylmethoxysilyl)benzene, 1,1,3,3-tetramethyl-1,3-disila-2-oxaindane, and 1, 1-dimethyl-1-silarribenzocycloheptatriene. When I is polymerized with H2SO4, the phenyl group is observed to split off.  相似文献   

7.
用pH电位法研究了1-乙酰胺基丙叉-1,1-二膦酸(S-186)和1-丙酰胺基乙叉-1,1-二膦酸(S-106)与碱土金属的螯合作用(30±O.1℃).当金属离子与配体的摩尔浓度比为10∶1、1∶1和1∶2时,在水溶液中形成了MHL、ML、ML_2和M_2L等几种类型的配合物.分别测定了它们的稳定常数,其中S-186配合物稍高于S-106,说明配合物稳定性与螯合剂的碱度有平行关系.值得注意的是,这两种螯合剂与Sr~(2 )形成的双核配合物的稳定性均较其它碱土金属离子的为高.  相似文献   

8.
The rearrangement of enol acylates of aryl 1H-1, 2, 4-triazol-1-ylmethyl ketones at 140–150°C in acetic anhydride is studied. The migration of the acyl group to the C(5) atom of the heterocycle is found to be intramolecular. The characteristics of the original and final products are presented. X-ray structural studies of the enol acetates of 2, 4-dichlorophenyl 1H-1, 2, 4-triazol-1-ylmethyl ketone and 2, 4-dichlorophenyl 5-acetyl-1H-1, 2, 4-triazol-1-ylmethyl ketone are carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 560–564, March, 1993.  相似文献   

9.
许家喜  兰若曦  金声 《化学学报》1999,57(12):1359-1363
通过2-甲基-4-(4-甲氧基苯基)-2,3-二氢-1,5-苯并硫氮杂卓与二氯卡宾的[2+1]环加成反应制备了标题化合物,用X射线单晶衍射测定了其晶体结构。分子式C~1~8H~1~7Cl~2NOS,分子量366.30,晶体属正交晶系,空间群P~b~c~a,晶胞参数:a=1.2246(3)nm,b=1.5219(4)nm,c=1.9272(9)nm,V=3.592(2)nm^3,Z=8,D~c=1.355g.cm^-^3。位于中心的1,5-硫氮杂卓环为扭曲的类船式构象,船头与苯环并合,船底与吖丙啶环并合。  相似文献   

10.
11.
The reductive conversion of 1, 3-dimethylthymine bromohydrin into 1, 3-dimethylthymine by 10-ethyl-3-methyl-1, 5-dihydro-5-deazaflavin or 1-benzyl-3-carbamoyl-1, 4-dihydroquinoline has been achieved in the presence of trifluoroacetic acid.  相似文献   

12.
Four electronically low-lying states of silylene (SiH2) have been studied systematically using high level ab initio electronic structure theory. Self-consistent field (SCF), two-configuration (TC) SCF, complete active space (CAS) SCF, configuration interaction with single and double excitations (CISD), and CASSCF second-order (SO) CI levels of theory were employed with eight distinct basis sets. The zeroth-order wave functions of the ground ( 1A1 or 1 1A1) and 1A1 (or 2 1A1) excited states are appropriately described by the first and second eigenvectors of the TCSCF secular equations. The TCSCF-CISD, CASSCF, and CASSCF-SOCI wave functions for the 1A1 (or 2 1A1) state were obtained by following the second root of the CISD, CASSCF, and SOCI Hamiltonian matrices. At the highest level of theory, the CASSCF-SOCI method with the triple zeta plus triple polarization augmented with two sets of higher angular momentum functions and two sets of diffuse functions basis set [TZ3P(2f,2d)+2diff], the energy separation (T0) between the ground ( 1A1) and first excited ( 3B1) states is determined to be 20.5 kcal/mol (0.890eV,7180cm−1), which is in excellent agreement with the experimental T0 value of 21.0 kcal/mol (0.910eV,7340cm−1). With the same method the T0 value for the 1B1 1A1 separation is predicted to be 45.1 kcal/mol (1.957 eV,15780 cm−1), which is also in fine agreement with the experimental value of 44.4 kcal/mol (1.925 eV,15530 cm−1). The T0 value for the 1A1 1A1 separation is determined to be 79.6 kcal/mol (3.452 eV,27 840 cm−1). After comparison of theoretical and experimental T0 values for the 3B1 and 1B1 states and previous studies, error bars for the 1A1 state are estimated to be ±1.5 kcal/mol (±525 cm−1). The predicted geometry of the 1A1 state is re(SiH)=1.458 and θe=162.3. The physical properties including harmonic vibrational frequencies of the 1A1 state are newly determined. Received: 10 March 1997 / Accepted: 2 April 1997  相似文献   

13.
1, 1-Difluorocyclopropa[a]naphthalene ( 1b ) is prepared in three steps from 4-bromo-1,2-dihydronaphthalene ( 7 ) via carbene addition, benzylic bromination and bidehydrohalogenation. Structural evidence for formation of 1b is based on 1H- and 19F-NMR spectroscopy. Compound 1b is stable in solution at ?30°. Upon reaction with MeOH/H+ it is converted to a 1:2 mixture of 1- and 2-methylnaphthoate ( 10 and 11 , respectively).  相似文献   

14.
Zusammenfassung DieRaman- und Infrarotspektren der isotaktischen Poly--olefine Polydodecen-1, Polytetradecen-1, Polyhexadecen-1 und Polyoctadecen-1 wurden bei verschiedenen Temperaturen gemessen, um den Einfluß der Seitenketten auf den Ordnungszustand innerhalb dieser Polymeren zu untersuchen. Aus den Spektren der langsam aus der Schmelze abgekühlten Proben kann geschlossen werden, daß sich die meisten Methylengruppen der Seitenketten in einer planaren TT-Konformation befinden. Mit Beginn des ersten endothermen Peaks der DTA-Kurve wird eine Änderung dieser Struktur beobachtet. Die gegenüber dieser Änderung des Ordnungszustandes besonders empfindlichen Banden finden sich in denRamanspektren im Bereich der CH2-bending-Schwingungen und im Bereich der CH2-rocking-Schwingungen bei den Infrarotspektren.
Summary For studying the influence of the side-chains on the state of orderRaman and infrared spectra of the isotactic poly--olefins polydodecene-1, polytetradecene-1, polyhexadecene-1 and polyoctadecene-1 were measured at different temperatures. The spectra of the slowly cooled samples show that most sidechain methylene groups form a planar TT-conformation. A change in this structure is observed at the beginning of the first endothermic DTA peak. The most sensitive bands due to this change in the state of order can be found in theRaman spectra in the range of the CH2-bending vibration and in the infrared spectra in the range of the CH2-rocking vibration.


Mit 9 Abbildungen und 2 Tabellen  相似文献   

15.
以氯甲烷(2)为原料制备甲基氯化镁格氏试剂;以三氯化镓为催化剂,甲基氯化镁与1,1,1-三氟丙酮(3)反应,经水解制得1,1,1-三氟-2-甲基-2-丙醇(1).产物结构经1 H-NMR、13 C-NMR、19 F-NMR及MS表征;通过单因素、正交实验和放大重复性实验确定了最佳反应条件:溶剂为正丁醚、格氏试剂浓度3 ...  相似文献   

16.
1-Trimethylsilyl-, 1-Trimethylgermyl-, and 1-Trimethylstannyl-3,4-dimethylphospholene 1-Lithium-3,4-dimethylphospholen reacts with Me3SiCl and Me3GeCl yielding 1-trimethylsilyl-3,4-dimethylphospholene ( 1 ) and 1-trimethylgermyl-3,4-dimethylphospholene ( 2 ) respectively. 2 and 1-trimethylstannyl-3,4-dimethylphospholene ( 3 ) are formed using the reaction of 1 with Me3GeCl and Me3SnCl respectively. The 1H, 13C and 31PNMR-spectra as well as the mass spectra of the new compounds are discussed.  相似文献   

17.
The 1,5-diphenyl-1,5-azapentanediyl biradical Ia was generated by photolysis of 1,2-diphenylazacyclopentane (pyrrolidine 1a). Among the reaction pathways followed by Ia, C-N bond reformation with ring closure was found to be the predominating process, as determined by separate irradiation of either of the pure enantiomers of 1a. Disproportionation was a minor process and took place only via H abstraction by the C5 benzylic radical. Another minor pathway was C5-aryl coupling, with formation of 5-phenyl-2,3,4,5-tetrahydro-1H-benzo[b]azepine (4a), which is equivalent to photo-Claisen rearrangement of 1a. Likewise, the 1,4-diphenyl-1,4-azabutanediyl biradical Ib was generated by photolysis of 1,2-diphenylazacyclobutane (azetidine 1b). This species underwent predominating C2-C3 cleavage, as indicated by the extensive styrene formation. Although N1-C4 bond reformation also took place, this is not the major pathway occurring from Ib. Besides, C4-aryl coupling to give 4-phenyl-1,2,3,4-tetrahydroquinoline (4b) was also observed. All the possible reaction pathways were theoretically studied at the UB3LYP/6-31G computational level; the results were found to be in good agreement with the experimental observations.  相似文献   

18.
Hydrolysis of hexacyanocyclopropane (1a), ethyl 1,2,2,3,3-pentacyanocyclopropane-1-carboxylate (1b), 1,2,2,3,3-pentacyanocylopropane-1-carboxamide (1c), andN,N-dimethyl-1,2,2,3,3-pentacyanocylopropane-1-carboxamide (1d) in 95% acetic acid yieldsr-1,c-2,c-3-tricyanocyclopropane-t-1-carboxamide (3). The structure of3 was proved by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 454–456, March, 1998.  相似文献   

19.
1-Aryl- and 1-Alkyl-2-phathalimido-diazene-1-oxides, Diacylated Examples of Trisubstituted Triazene-1-oxides: Formation, Properties, Stereoisomerization and Fragmentation1) Oxidatively generated phthalimido-nitrene ( 1 ) reacts with nitrosobenzene ( 8a ), p-nitrosotoluene ( 8b ), o-nitrosotoluene ( 8c ), p-dimethylamino-nitrosobenzene ( 8d ), p-methoxycarbonyl-nitrosobenzene ( 8e ), 1, 1-dimethyl-1-nitrosoethane ( 8f ) and nitrosocyclohexane ( 8g ) to give the respective 1-substituted (Z)-2-phthalimidodiazene-1-oxides 14a-g . The constitution of 2-imidodiazene-1-oxides 14 is deduced from their spectroscopic properties. The UV. spectra of 14a-e are similar with those of the corresponding nitrobenzenes 18 , thus supporting the concept of comparibility of the phthalimido-N group with an O-atom and indicating that the phthalimido group is not in conjugation with the diazene-oxide function. This is in contrast to the situation in the non-acylated trisubstituted triazene-1-oxides 12 , where conjugation is extended over the chain of all three N-atoms as exhibited by the UV. spectra of (Z)-1, 3, 3-triphenyl-, (Z)-3, 3-dimethyl-1-phenyl-, (Z-3-methyl-1, 3-diphenyl-, (Z)-1-(1, 1-dimethylethyl)-3, 3-diphenyl-, and (Z)-1-(1, 1-dimethylethyl)-3, 3-dimethyltriazene-1-oxide ( 12a-e ). These triazene-1-oxides are formed by the reaction of 1, 1-disubstituted hydrazines 11 with three mol-equiv. of nitroso compounds 8 or from equimolar amounts of 11 and 8 in the presence of mercury oxide. Over 90% of 1, 2-diphenyldiazeneoxide ( 19 , R = C6H5) are isolated by the reaction 11 + 3 8a . Possible mechanisms of the reaction of 11 with 8 , and of the formation of 12 via triazanols D and of 19 (R = C6H5) via N-Phenylhydroxylamine ( 20 , R = C6H5) are given in Scheme 6 (in the latter case with experimental evidence). An independent synthesis of 12c confirms the constitutional assignment for 12 .  相似文献   

20.
Electronic and vibrational structures in the S(0) (1)A(1) and S(1) (1)A(1) states of jet-cooled phenanthrene-h(10) and phenanthrene-d(10) were analyzed by high-resolution spectroscopy using a tunable nanosecond pulsed laser. The normal vibrational energies and molecular structures were estimated by ab initio calculations with geometry optimization in order to carry out a normal-mode analysis of observed vibronic bands. The rotational structure was analyzed by ultrahigh-resolution spectroscopy using a continuous-wave single-mode laser. It has been demonstrated that the stable geometrical structure is markedly changed upon the S(1) ← S(0) electronic excitation. Nonradiative internal conversion in the S(1) state is expected to be enhanced by this structural change. The observed fluorescence lifetime has been found to be much shorter than the calculated radiative lifetime, indicating that the fluorescence quantum yield is low. The lifetime of phenanthrene-d(10) is longer than that of phenanthrene-h(10) (normal deuterium effect). This fact is in contrast with anthracene, which is a structural isomer of phenanthrene. The lifetime at the S(1) zero-vibrational level of anthracene-d(10) is much shorter than that of anthracene-h(10) (inverse deuterium effect). In phenanthrene, the lifetime becomes monotonically shorter as the vibrational energy increases for both isotopical molecules without marked vibrational dependence. The vibrational structure of the S(0) state is considered to be homogeneous and quasi-continuous (statistical limit) in the S(1) energy region.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号