201 resultados para 1,3-propanediol


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A poly(o-toluidine) (POT)/2,5-dimercapto-1,3,4-thiadiazole (DMcT) composite was prepared. When POT and DMcT are mixed in a proper solvent, POT in a medium-oxidation state is reduced, and DMcT in turn is oxidized to its soluble dimer when the molar ratio of DMcT to POT is higher than 0.5. Therefore, the composite was soluble in organic solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP) and exhibited very high electroactivity, two orders of magnitude higher than that of pure POT and three orders of magnitude higher than that of pure DMcT. Molecular-level contact between POT and DMcT is the reason for the improved catalytic effect of POT on DMcT, compared to that of polyaniline on DMcT. (C) 1999 The Electrochemical Society. S0013-4651(98)08-059-8. All rights reserved.

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报道了3-苯基-1-丁炔-3-醇的常规电子轰击质谱(EIMS).利用碰撞诱导解离(CID)技术研究了质谱碎裂过程中产生的[C_8H_7]~+的气相离子结构.同时,氘代同位素交换、亚稳(MI)和CID实验进一步证实了m/z103离子的形成并不是分子离子的质谱碎裂中顺次失去甲基自由基和中性CO分子的直接氢迁移的协同反应,而是在失去CO分子前后发生了二次质子迁移反应的逐步过程.在此基础上提出了一种独特的双分子质子键合复合物中间体的碎裂机理.

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beta, beta-1, 3-Piopylenedithio-alpha, beta-unsaturated arylketones 2 via chemoselective 1,2-addition with allyl or benzyl Grignard reagents afforded the corresponding carbinols 3 and 4. Catalysed by silica gel, the carbinols 3 and 4 were converted to the beta,gamma-unsaturated arylketones 5, 6. The mechanism and reaction condition were discussed.

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以β,β-1,3-亚丙二硫基-α,β-不饱和芳酮2与烯丙基或等基Grfenard试剂可选择性地进行1,2-加成得醇3、4,在硅胶G的催化下,醇3、4可分解生成β,γ-不饱和芳酮5、6.并对该分解反应的机制进行了初步探讨.

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Crystal structure and polymorphism induced by uniaxial drawing of a poly(aryl ether ketone) [PEDEKmK] prepared from 1,3-bis(4-fluorobenzoyl)benzene and biphenyl-4,4'-diol have been investigated by means of transmission electron microscopy (TEM), electron diffraction (ED), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) techniques. The melting and recrystallization process in the temperature range of 250-260 degrees C, far below the next melting temperature (306 degrees C), was identified and found to be responsible for the remarkable changes in lamellar morphology. Based on WAXD and ED patterns, it was found that crystal structure of isotropic-crystalline PEDEKmK obtained under different crystallization conditions (melt-crystallization, cold-crystallization, solvent-induced crystallization, melting-recrystallization, and crystallization from solution) keeps the same mode of packing, i.e., a two-chain orthorhombic unit cell with the dimensions a = 0.784 nm, b = 0.600 nm, and c = 4.745 nm (form I). A second crystal modification (form II) can be induced by uniaxial drawing above the glass transition temperature, and always coexists with form I. This form also possesses an orthorhombic unit cell but with different dimensions, i.e., a = 0.470 nm, b = 1.054 nm, c = 5.064 nm. The 0.32 nm longer c-axis of form II as compared with form I is attributed to an overextended chain conformation due to the expansion of ether and ketone bridge bond angles during uniaxial drawing. The temperature dependence of WAXD patterns for the drawn PEDEKmK suggests that form II can be transformed into the more stable form I by relaxation of overextended chains and relief of internal stress at elevated temperature in absence of external tension.

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The compounds O(CH2CH2C5H4)(2)Ln(THF)(2) [Ln = Sm(1), Yb(2)] were synthesized by the reduction of O(CH2CH2C5H4)(2)LnCl with sodium metal in tetrahydrofuran (THF) at room temperature. Recrystallization of 2 from dimethoxyethane (DME) produced the single-crystal O(CH2CH2C5H4)(2)Yb(DME) (3) whose structure has been determined by an X-ray diffraction study. The crystals are orthorhombic, space group Pcab, with a = 14.168(4), b = 13.541(6), c = 19.314(8) Angstrom, Z = 8, D-calc. = 1.66 g cm(-3).

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Using two methods: (1) three-step excitation and (2) single UV photon excitation in an atomic beam with direct observation of the decay of the fluorescence light, we have measured the lifetimes of the Rydberg levels of YbI belonging to the perturbed series 6snp J = 1 levels. The measured values have been interpreted by the multichannel quantum defect theory (MQDT).

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报导了标题化合物C_(10)H_(14)OS_2(M_r=214.35)的晶体结构,该晶体属正交晶系,空间群为P2_12_12_1,晶胞参数为a=6.443(3),b=8.980(4),c=18.213(7);V=1053.8(6)3;Z=4,D_x=1.35g/cm~3,F(000)=455,μ=4.5cm~(-1)(MoKa)。最终偏离因子R=0.033,R_w=0.034。分子中的两支C_(sp)2-S键键长近于相等,分别为1.761(3)和1.769(3),C(1)-C(5)键长为1.361(4)。

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本文报道9种新的含磷杂环化合物的电子轰击质谱(EIMS),并应用B/E、B2/E联动扫描及精确质量测量技术,探讨了该类化合物的质谱断裂机理,发现骨架重排及开环反应是该类化合物主要的质谱特征,而R2基因对重排过程有很大影响。

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Reaction of 1,3-cyclohexadiene(tricarbonyl)iron (1) with ortho-substituted aryllithium reagents ArLi (Ar=o-CH3C6H4, o-CH3OC6H4, o-CF3C6H4) in ether at low temperature, and subsequent alkylation of the acylmetalates formed with Et3OBF4 in aqueous solution at 0-degrees-C or in CH2Cl2 at -60-degrees-C gave the 1,3-cyclohexadiene(dicarbonyl)[ethoxy(aryl)carbene]iron complexes (eta4-C6H8)(CO)2FeC(OC2H5)Ar (3, Ar = o-CH3C6H4; 4, Ar = o-CH3OC6H4), and the isomerized product (eta3-C6H8)(CO)2FeC(OC2H5)C6H4CF3-o (5), respectively, among which the structure of 3 has been established by an X-ray diffraction study. Complex 3 is monoclinic, space group P2(1) with a = 8.118(4), b = 7.367(4), c = 14.002(6) angstrom, beta = 104.09(3)-degrees, V = 812.2(6) angstrom3, Z = 2, D(c) = 1.39 g cm-3, R = 0.056, and R(w) = 0.062 for 976 observed reflections. Complexes 3 and 5 were converted into the chelated allyliron phosphine adducts(eta3-C6H8)(CO)2(PR31)FeC(OC2H5)Ar (6, Ar = o-CH3C6H4, R1 = Ph; 7, Ar = o-CH3C6H4, R1 = OPh; 9, Ar = o-CF3C6H4, R1 = Ph), by reaction with phosphines in petroleum ether at low temperatures.

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提出了由β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物(1)与苄基氯化镁及烯丙基溴化镁加成所得的醇(2)在BF_3·Et_2O催化下脱水生成共轭烯烃(3)新的合成途径,合成了13种新化合物,结构经~1H N-MR、IR、UV及元素分析等确证.并对这一新合成途径的反应机制进行了讨论.

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本文研究了TritonX-100在浊点条件下对钴-4-(5-氯-2-吡啶偶氮)-1,3-二氨基苯(5-Cl-PADAB)络合物的析相条件,在pH4.0~6.0介质中,将胶束溶液加热到92±1℃,保持40min,络合物即被TritonX-100相富集。富集液在575nm测定吸光度,钴含量在0~4μg/5ml范围内服从比尔定律,干扰离子可在TritonX-100析相液中加入H_2SO_4消除。拟定的方法灵敏、简捷,已用于不经分离直接测定人发及自来水中痕量钴。

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[CoCl4(C3H12N2)], M(r) = 276.87, monoclinic, P2(1)/n, a = 10.703 (2), b = 10.653 (1), c = 10.852 (2) angstrom, beta = 118.46 (1)-degrees, V = 1087.8 angstrom 3, Z = 4, D(x) = 1.69 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 22.60 cm-1, F(000) = 556, T = 298 K, final R = 0.059 for 1068 unique reflections [I > 3-sigma(I)]. The Co(II) ion is coordinated by four Cl atoms in a tetrahedral geometry. The paraffinic chains which bridge the tetrahedra have a nearly planar zigzag configuration.

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β,β-二烷硫基-α,β-不饱和酮类化合物作为一类具多反应中心的活泼中间体在有机合成中的应用,近20年来已引人注目并进行了深入广泛的研究~[1,2].以往的研究大多是针对β,β-二甲硫基-α,β-不饱和酮类化合物1进行的,而对结构相近的β,β-1,3-亚丙二硫基-α,β-不饱和酮类化合物2的研究较少.对于1类的合成,所用碱的选择至关重要~[1].实验证明叔丁醇钠和叔丁醇钾~[3~5]在1类的合成中效果较好.前文~[6]曾以六甲基二硅氨基锂(LHMDS)为碱高

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The mass spectral behaviour of 15 new type of organic phosphorus compounds with a considerable insecticidal activity, 1, 3,2-oxazaphospholidine 2-sulfides derivatives, under 70 eV electron impact has been studied by means of high and low resolution mass spectrometry as well as by B/E linked scan and MIKES/CID analysis. Discussion is focused into the isomerization between oxygen and sulphur in molecules and some rearrangement reactions.