Normal vibrational analysis of poly(vinylidene chloride)

Normal coordinate calculations have been performed for poly(vinylidene chloride) employing a TXTX′ conformational model (X and X′ denote torsional angles of equal value but opposite sign). A valence force field previously determined from the model compounds 2,2-dichloropropane and 2,2-dichlorobutane was directly transferred to the chain conformation of the polymer. The results are in excellent agreement with the observed vibrational spectra and we have been able to satisfactorily assign all the major normal modes.     

一些烷氯代烃标准蒸发焓的测定

在进行有机氯化物分子内非键合相互作用的热化学研究中, 为了排除分子间的相互作用, 需要准确的标准蒸发焓或升华焓, 以便把凝聚态的标准生成焓转变为气态的数据。文献中多氯代烷烃的蒸发焓数据不多, 其中由直接量热法得到的准确数据更少, 因此我们测量了一些多氯代烷烃的标准蒸发焓, 并对其规律作了一些探讨。     

Kinetics, products, and stereochemistry of the reaction of chlorine atoms with cis- and trans-2-butene in 10-700 Torr of N2 or N2/O2 diluent at 297 K

The reactions of Cl atoms with cis- and trans-2-butene have been studied using FTIR and GC analyses. The rate constant of the reaction was measured using the relative rate technique. Rate constants for the cis and trans isomers are indistinguishable over the pressure range 10-900 Torr of N2 or air and agree well with previous measurements at 760 Torr. Product yields for the reaction of cis-2-butene with Cl in N2 at 700 Torr are meso-2,3-dichlorobutane (47%), DL-2,3-dichlorobutane (18%), 3-chloro-1-butene (13%), cis-1-chloro-2-butene (13%), trans-1-chloro-2-butene (2%), and trans-2-butene (8%). The yields of these products depend on the total pressure. For trans-2-butene, the product yields are as follows: meso-2,3-dichlorobutane (48%), dl-2,3-dichlorobutane (17%), 3-chloro-1-butene (12%), cis-1-chloro-2-butene (2%), trans-1-chloro-2-butene (16%), and cis-2-butene (2%). The products are formed via addition, addition-elimination from a chemically activated adduct, and abstraction reactions. These reactions form (1) the stabilized 3-chloro-2-butyl radical, (2) the chemically activated 3-chloro-2-butyl radical, and (3) the methylallyl radical. These radicals subsequently react with Cl2 to form the products via a proposed chemical mechanism, which is discussed herein. This is the first detailed study of stereochemical effects on the products of a gas-phase Cl+olefin reaction. FTIR spectra (0.25 cm(-1) resolution) of meso- and DL-2,3-dichlorobutane are presented. The relative rate technique was used (at 900 Torr and 297 K) to measure: k(Cl + 3-chloro-1-butene) = (2.1 +/- 0.4) x 10(-10), k(Cl + 1-chloro-2-butene) = (2.2 +/- 0.4) x 10(-10), and k(Cl + 2,3-dichlorobutane) = (1.1 +/- 0.2) x 10(-11) cm3 molecule(-1) s(-1).     

主链型阳离子表面活性剂聚季铵盐的制备

以N,N-二甲基-1,3-丙二胺、尿素及1,4-二氯丁烷为原料,通过共缩聚反应两步法制备了一种新的主链型的水溶性聚季铵盐.采用正交试验获得了制备聚季铵盐的最佳条件：N,N-二甲基-1,3-丙二胺与尿素的物质的量比为2∶1,反应温度为135℃,反应时间为11h,得到中间体双[3-（N,N-二甲基丙胺基）]丙脲,产率高达99％;中间体与1,4-二氯丁烷的物质的量比为1∶1,于90℃下反应6h.采用红外光谱和核磁氢谱对产物结构进行表征,测定了其热稳定性和特性粘数.     

Effects of chlorinated aliphatic hydrocarbons on the fidelity of cell division in human CYP2E1 expressing cells

Chlorinated organic chemicals are widely used in industry and are present in the environment. Five chlorinated aliphatic hydrocarbons, namely 1-2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, 2,3-dichlorobutane and 1-chlorohexane were investigated to determine their influence upon the fidelity of cell division in cultured mammalian cells. In order to determine the influence of these chemical compounds upon the fidelity of cell division, a technique known as differential staining of chromosomes and spindle was performed with one genetically engineered cell line and its parental cell line. The genetically engineered cell line used in this study expressed a human P450 enzyme, CYP2E1. Four chemicals, 1-2-dichloroethane, trichloroethylene, 2,3-dichlorobutane and 1-chlorohexane required metabolic bioactivations in order to induce spindle damage in cultured mammalian cells whereas 1,1,2-trichloroethane was a direct-acting spindle poison.     

Viscosities of 1-chlorobutane and 1,4-dichlorobutane with isomeric butanols at 25 and 40°C

This paper reports viscosities and excess viscosities for binary systems of 1-chlorobutane and 1,4-dichlorobutane with isomeric butanols at 25 and 40°C. Results show negative deviations from ideal behavior. Viscosities and excess viscosities were correlated by means of the Grunberg-Nissan equation and the Redlich-Kister equation.     

Isothermal vapour–liquid equilibrium data for the binary propan-2-one+chloroalkanes mixtures at temperatures from 298.15 K to 313.15 K

Isothermal vapour–liquid equilibrium data are reported for binary mixtures of propan-2-one with 1,1,2,2-tetrachloroethane (I) and 1,4-dichlorobutane (II) within the 298.15–313.15 K temperature range. Total vapour pressures were measured by a static method, the mixtures beeing prepared by weight and degased directly into the working cell. The experimental data were correlated by Barker's method and different expressions for excess Gibbs energy were tested. The results indicate negative deviation from ideality for mixture (I), while mixture (II) behaves almost ideally, with slightly positive deviations.     

Vibrational spectrum, ab initio calculations, conformational stabilities and assignment of fundamentals of the Ci conformer of 1,4-dichlorobutane

The infrared and Raman spectrum of 1,4-dichlorobutane is reported in solid, liquid and gas. Ab initio calculations for the nine stable or metastable conformers of 1,4-dichlorobutane are reported for Moller-Ploessett second order electron correlation and B3LYP density functionals with a variety of basis sets, using approximations as high as 6-311+g(2d, 2p). Normal coordinate calculations were conducted for the nine conformers and the results used to provide assignments for some of the observed infrared and Raman bands. An attempt to use the assignments together with the ab initio intensities or Raman activities to investigate the composition of the liquid at room temperature proved modestly successful, and suggested that the populations are altered from those expected in the gas phase by interactions of the permanent electric dipole moments with the dipolar plasma in which the conformers are immersed in the liquid. A substantial disagreement between the Moeller-Ploessett and density functional results is reported, and the calculation of intensities and activities is insufficiently accurate to allow detailed interpretation of the spectrum of the room temperature liquid. A complete assignment of fundamentals is given for the conformer of Ci symmetry, and one Raman and one infrared band is identified with the C2h conformer. All the other infrared and Raman bands in the liquid or the gas are composites of several contributors.     

2-氯丁烷、1,2=二氯丁烷气态生成焓的测量

用转动氧弹燃烧热量计测量了298.15K时2-氯丁烷和1,2-二氯丁烷的标准液态燃烧反应内能变化值,得到了它们的标准所态生成焓值,并进一步考查了二氯取代地氯代烷烃气态生成焓值的影响量.     

Interaction of alkali metals with unsaturated heterocyclic compounds. The reductive metalation of 1,4-diphenylphthalazine

1,4-Diphenylphthalazine ( 1 ) was reduced in tetrahydrofuran by sodium metal to a monomeric dianion 2 . Chemical reactions of this new dianion were examined with various reagents. Generally, the protonation, acylation and alkylation products were 1,2-dihydrophthalazine derivatives. An annulation of the phthalazine ring system was accomplished by treating the dianion with 1,3-dichloropropane or 1,4-dichlorobutane. With 1,2-dichloroethane however, only 1,4-diphenylnaphthalene was detected.     

Radiation yield of stable radiolysis products of 1-chlorobutane, 1-chlorobutene-2, 1-chloropropane, 2-chloropropane and 1,3-dichloropropane γ-irradiated in an oxygen-free atmosphere

The stable radiolysis products of 1-chlorobutane (1-CB), 1-chlorobutene-2 (1-CB-2), 1-chloropropane (1-CP), 2-chloropropane (2-CP) and 1,3-dichloropropane (1,3-DCP) gamma-irradiated in an oxygen-free atmosphere have been investigated. The pure radiolysis products were separated by preparative gas chromatography and identified by NMR and mass spectroscopy as well as qualitative gas chromatography. The compounds formed were determined by potentiometric analysis and quantitative gas chromatography. From 1-CB we have obtained in the gas phase: HCl, H₂, butane; in the liquid phase: 2-chlorobutane, 1,3-dichlorobutane and a mixture of oligomers of the initial compound (dimer and trimer). We have not recorded H₂ in 1-CB-2. The main gaseous products of radiolysis of 1-CP are HCl and H₂. Radiation yield of isomerization was determined. From 2-CP we have obtained in the gas phase: HCl and H₂; in the liquid phase: 2,2-dichloropropane and a mixture of oligomers of the initial compound (dimers and trimers). From 1,3-DCP we have found in the gas phase: HCl and H₂; in the liquid phase: 1-CP, 2-CP, 1,2-DCP and oligomers. Preliminary schemes for the formation of stable products are proposed.     

Excess and partial excess molar volumes of 1,4-dichlorobutane with butanols at 25 and 40°C

From density measurements over the whole composition range at 25 and 40°C excess molar volumes for binary mixtures of 1,4-dichlorobutane with l-butanol, 2-butanol, 2-methyl-l-propanol or 2-methyl-2-propanol are calculated. V^E results were fitted by the method of least squares to a smoothing equation. Excess partial molar volumes and limiting excess partial molar volumes at 25° are also calculated.     

Vibrational analysis of 1,1-dichlorobutane

IR and Raman spectra have been obtained for 1,1-dichlorobutane and interpreted with the aid of normal coordinate calculations. It is concluded that this compound exists in three conformations in the liquid and glassy solid states but crystallizes only in the conformer that has all four carbons coplanar and both chlorines out of that plane (C_s symmetry).     

Recombination dynamics and hydrogen abstraction reactions of chlorine radicals in solution

We observe chlorine radical dynamics in solution following two-photon photolysis of the solvent, dichloromethane. In neat CH(2)Cl(2), one-third of the chlorine radicals undergo diffusive geminate recombination, and the rest abstract a hydrogen atom from the solvent with a bimolecular rate constant of (1.35 +/- 0.06) x 10(7) M(-1) s(-1). Upon addition of hydrogen-containing solutes, the chlorine atom decay becomes faster, reflecting the presence of a new reaction pathway. We study 16 different solutes that include alkanes (pentane, hexane, heptane, and their cyclic analogues), alcohols (methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol), and chlorinated alkanes (cyclohexyl chloride, 1-chlorobutane, 2-chlorobutane, 1,2-dichlorobutane, and 1,4-dichlorobutane). Chlorine reactions with alkanes have diffusion-limited rate constants that do not depend on the molecular structure, indicating the absence of a potential barrier. Hydrogen abstraction from alcohols is slower than from alkanes and depends weakly on molecular structure, consistent with a small reaction barrier. Reactions with chlorinated alkanes are the slowest, and their rate constants depend strongly on the number and position of the chlorine substituents, signaling the importance of activation barriers to these reactions. The relative rate constants for the activation-controlled reactions agree very well with the predictions of the gas-phase structure-activity relationships.     

Thionin derivatives in the extraction and direct photometric determination of boron

Thionin and nine commercially available thionin derivatives were studied for their applicability in the analytical solvent extraction and direct photometric determination of boron, Azure A, Azure B, Azure C, Methylene Blue, New Mcthylene Blue N, Méthyléne Green, Toluidine Blue O, Thionin and the cosinates of Azure A and B were investigated. Over thirty organic solvents, mostly chlorinated or brominated were tried with these dyes. 1,2-Dichloroethane, 1,2-dichloropropane, dichloromethane, I,I,2-trichlorocthane, cis-dichloroethylene, o-dichlorobenzene, 1,4-dichlorobutane and mixtures of these solvents proved applicable. Many good dye-solvent combinations were found which were very attractive for the separation and determination of various amounts of boron. Only thionin itself proved unsatisfactory.     

Hexadecahydrotetrabenzo[a,c,d,f]fluorene - Ligand, available by Friedel-Crafts fluorene cycloalkylation. Synthesis, crystal and molecular structure of (η-C29H34)(η-C5H5)ZrCl2

Friedel-Crafts cycloalkylation of fluorene with 1,4-dichlorobutane has been studied in different conditions. This reaction allows to obtain the product of exhausting fluorene alkylation, hexadecahydrotetrabenzo[a,c,d,f]fluorene - perspective η⁵ ligand. The simplest zirconocene has been synthesized and its structure has been confirmed by X-ray diffraction analysis. The molecule of this compound possesses skewed conformation of metallocene fragment with the phenylene moiety of fluorenyl ligand oriented towards the front side of metallocene wedge.     

The reductive metalation of 9-phenylacridine

The reductive metalation of 9-phenylacridine by sodium to a dianion is described and the reactions of the dianion with electrophiles investigated. Reactions of the dianion with methanol, dimethyl sulfate, X(CH₂)_nX (n = 2,3,4, X = Cl, Br), and methyl chloroformate were studied. Reactions occurred exclusively at the 9 and 10 positions forming 9,10-dihydro-9-phenylacridine derivatives. Of particular interest was the fact that the dianion was dialkylated with 1,2-dichloroethane but monoalkylated at the 9-position with 1,3-dichloropropane and 1,4-dichlorobutane. These results are compared to those obtained with dianions derived from other heterocyclic systems and analyzed using Baldwin's Rules for Ring Closure.     

SYNTHESIS OF SOME BICYCLIC OXAZOLO- AND OXAZEPINOPYRIMIDINE DERIVATIVES

Oxazolopyrimidine compounds 2(a–c) and 3(a–e) were synthesized by a simple one-pot condensation reaction of the pyrimidine derivative 1 with 1,2-dibromoethane and 2-bromopropanoic acid, respectively. In a similar way the oxazepinopyrimidine compounds 4(a–b) were synthesized by reaction of 1 and 1,4-dichlorobutane in dioxane under reflux condition. The yields of products following recrystallization were of the order of 55–85%.     

Refractive Indices Measurement and Correlation for Selected Binary Systems of Various Polarities at 25 °C

New refractive indices at 25 °C were measured and are reported here for 19 binary mixtures of pentan-3-one+1,2-dichloroethane, +1,3-dichloropropane, +1,4-dichlorobutane, +trichloromethane, +1,1,1-trichloroethane, +1,1,2,2-tetrachloroethane; cyclopentanone+1-chlorobutane, +1,1,2,2-tetrachloroethane; cyclohexanone+1,1,2,2-tetrachloroethane; 5-chloro-2-pentanone+n-hexane, +toluene, +ethylbenzene; nitromethane+trichloromethane; and nitromethane or nitroethane, +1,2-dichloroethane, +1,3-dichloropropane, +1,4-dichlorobutane. The experimental refractive index deviations from linear mixing behavior have been evaluated and correlated consistently with the 3-parameter Redlich–Kister equation with good results. The molar refraction was also examined for the systems including pentan-3-one, cyclopentanone, cyclohexanone and 5-chloro-2-pentanone for which densities and excess molar volumes are available from previous works. Different theoretical (n, ρ) mixing rules were tested for these systems. The excess Gibbs energy G ^E and excess enthalpy H ^E values were considered together with the excess molar volumes V ^E, excess refractive indexes $ n_{\text{D}}^{\text{E}} $ , molar refraction R and excess molar refractions R ^E on mixing in the discussion of the influence of the alkyl chain length or of the nature of the second component in the mixture in terms of molecular interactions.     

Vibrational analysis of 1,2-dichloroalkanes

IR and Raman spectra have been obtained for 1,2-dichlorobutane and 1,2-dichloro- pentane. The butane crystallizes in the P_XS_XH conformation, but the pentane could not be made to crystallize. Normal coordinate calculations were made for the P_XS_XH, P_CS_HH, and P_HS_HH conformers of these two compounds and for 1,2-dichloropropane. The ob- served spectra were interpreted with the aid of these calculations, and it was concluded that all three conformers exist for each of these compounds. The force field that was obtained should be applicable to other 1,2-dichloroalkanes.