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研究了酸催化下的2, 6-二甲氧基-2-嘧啶氧基-N-芳基苄胺衍生物Smiles重排反应的动力学,考察了盐酸的初始浓度、溶剂、反应温度和取代基对反应速率的影响。结果表明,盐酸的初始浓度增加,重排反应速率加快;在单一溶剂中反应速率的顺序为:甲醇>乙醇>二甲基亚砜>乙腈,而在甲醇/水(1:1, V/V)的混合溶剂中反应速率明显增加,其表观反应速率常数(kobs)值是甲醇溶剂中的5.27倍;在25-45 ℃温度范围内,各衍生物的反应速率随着温度的升高而加快,其活化能(73.99-76.92 kJ·mol-1)、活化焓(71.57-74.38 kJ·mol-1)及Gibbs自由能(81.51-85.77 kJ·mol-1)数值相近,仅活化熵(-24.38 --47.11 J·K-1·mol-1)有一定的差别;取代基常数和表观速率常数之间呈现一定的线性关系,环上吸电子基团的存在有利于反应速率的提高;实验验证了反应机理的合理性。 相似文献
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测试了反-1,2-双[2-(5-苯基 唑基)]乙烯(POEOP)类化合物在1,4-二氧六环中的荧光寿命及其在不同溶剂中的光二聚量子产率,计算了其荧光辐射速率常数和非辐射速率常数,研究了取代基效应及溶剂性质对该类化合物光二聚反应的影响。结果发现,溶剂的极性增加有利于光二聚反应,但重原子溶剂对光二聚反应不利,表明该类化合物经单重态历程进行光二聚. 相似文献
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研究了乙醇-丙烯酸体系在低剂量下的γ辐解产物H_2、2,3-丁二醇及乙醛的生成.结果表明,乙醛不是在α-羟乙基自由基的歧化反应中生成的,而是来源于刺迹中的快反应;在该体系中丙烯酸(未与溶剂化电子反应)可清除H原子,其反应速率常数k_4=7.5×10~(9)mol~(-1)s~(-1);2,3-丁二醇由α-羟乙基自由基的再结合反应生成,动力学方程可表示为:G=G_0—[k_(11)/2(k_10)~(1/2)](G/K'D)~(1/2)[AAH]. 相似文献
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离子液体中脂肪酶催化拆分外消旋烯丙酮醇反应 总被引:2,自引:0,他引:2
以离子液体为溶剂,考察了溶剂类型、水活度、温度、 pH值和共溶剂等因素对脂肪酶催化拆分外消旋烯丙酮醇(R,S)-4-羟基-3-甲基-2-(2-丙烯基)-2-环戊烯-1-酮反应的影响,并与常用于外消旋烯丙酮醇拆分的有机溶剂乙酸乙烯酯进行了比较. 结果表明,在离子液体[bmim]PF6中脂肪酶的催化性能较好,酶初始反应速率为18.48 μmol/(g·min), 半衰期为74.53 h, 高于在乙酸乙烯酯中的相应值(9.18 μmol/(g·min)和64.29 h). 但离子液体中拆分反应的转化率低于在乙酸乙烯酯中的转化率,可以通过向离子液体中补加酰基供体来提高外消旋烯丙酮醇的转化率. 两种反应介质中最佳酶反应条件均为水活度0.17, 温度40 ℃和pH=7, 但加入共溶剂后,离子液体中脂肪酶催化拆分外消旋烯丙酮醇的效率降低,而在乙酸乙烯酯中则有所提高. 相似文献
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阳离子表面活性剂溴代十六烷基吡啶胶束对2,4-二硝基氯苯水解反应的影响 总被引:1,自引:0,他引:1
阳离子表面活性剂溴代十六烷基吡啶(CPB)胶束对水中OH-和2, 4-二硝基氯苯的反应有催化作用.随CPB浓度的增大, 反应速率常数开始时迅速增大, 然后趋于常数.OH-浓度的增大使胶束催化水解的二级速率常数减小.CPB胶束对此反应的速率提高作用比十六烷基三甲基溴化扶胶束更有效.对这两种胶束催化作用的差异进行了讨论. 相似文献
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钾镁氯化物(硫酸盐)与脲、水体系的溶度研究 总被引:7,自引:0,他引:7
报导了KCl-MgCl2-CO(NH2)2-H2O和K2SO4-MgSO4-CO(NH2)2-H2O两个四元体系在25℃时的溶度及其饱和溶液的折光率、密度,相应的溶度图和组成-折光率、组成-密度图.前一体系中形成3个三元化合物:MgCl2·4CO(NH2)2·2H2O、MgCl2·CO(NH2)2·4H2O和KCl·MgCl2·6H2O溶度盐份图由9支共饱线、4个四元无变点组成.四元体系的水量图、性质-组成图有类似的变化.后一体系中有2个异成份溶解化合物MgSO4·CO(NH2)2·2H2O和K2SO4·MgSO4·6H2O形成,溶度等温图由7支双饱溶度线、3个四元无变点组成.对两个体系相图的相似性和差异点进行了讨论. 相似文献
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对若干线型Mo一Fe一S簇合物[Cl2FeS2MoS2FeCl2][-2](1)、[S2MoS2FeCl2]^2^-(2)、[S2MoS2Fe(SPh)2][2-](3)、[S2MoS2FeS2Fe(SPh)2][3-](4)、[S2MoS2FeS2MoS2][3-](5)、Cl2FeS2FeCl2][2-](6)、[(PhS)2FeS2Fe(SPh)2][2-](7)的红外光谱进行了研究。通过比较它们的特征频率、结构参数和金属原子的氧化态,对νMo-St、νMo-SbνFe-Sb、νFe-SPh、νFe-Cl进行了归属。并对δS-Mo-S的归属作了初步探讨。文中讨论了MoS2Fe单元中Mo原子对νFe-Sb的影响, 通过振动频率与结构关系的研究揭示其内在联系及规律性。对两条途径的亲电诱导效应进行了讨论, 并提出一个能定性标志Fe→Mo电荷迁移大小的有用参数Δν值。 相似文献
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Ten polymeric silver(I) double salts containing embedded acetylenediide: [(Ag2C2)2(AgCF3CO2)9(L1)3] (1), [(Ag2C2)2(AgCF3CO2)10(L2)3]H2O (2), [(Ag2C2)(AgCF3CO2)4(L3)(H2O)]0.75 H2O (3), [(Ag2C2)(1.5)(AgCF3CO2)7(L4)2] (4), [(Ag2C2)(AgCF3CO2)7(L5)2(H2O)] (5), [(Ag2C2) (AgC2F5CO2)7(L1)3(H2O)] (6), [(Ag2C2)(AgCF3CO2)7(L1)3(H2O)]2 H2O (7), [(Ag2C2)(AgC2F5CO2)6(L3)2] (8), [(Ag2C2)2(AgC2F5CO2)12(L4)2(H2O)4]H2O (9), and [(Ag2C2)(AgCF3CO2)6(L3)2(H2O)]H2O (10) have been isolated by varying the types of betaines, the perfluorocarboxylate ligands employed, and the reaction conditions. Single-crystal X-ray analysis has shown that 1-4 all have a columnar structure composed of fused silver(I) double cages, with C2(2-) species embedded in its stem and an exterior coat comprising anionic and zwitterionic carboxylates. For 5 and 6, single silver(I) cages are linked into a beaded chain through both types of carboxylate ligands. In 7, two different coordination modes of L1 connect the silver(I) polyhedra into a chain. For 8, the mu(2)-O,O' coordination mode of L3 connects the silver(I) double cages into a chain. Compound 9 exhibits a two-dimensional architecture generated from the cross-linkage of double cages by C2F5CO2-, L4, and [Ag2(C2F5CO2)2] units. Similar to 9, 10 is also a two-dimensional structure, which is formed by connecting the chains of linked double cages through [Ag2(CF3CO2)2] bridging. 相似文献
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中心为氨基、末端为硝基的苯乙炔树枝状分子的合成 总被引:1,自引:0,他引:1
将固定相合成与“收敛/发散”方法相结合,合成了第一、二代苯乙炔树枝状分子.通过Heck-Cassar-Sonogashira-Hagihara偶联反应,将其中心和末端分别修饰上供电子的氨基和拉电子的硝基,得到第一、二代中心为氨基、末端为硝基的苯乙炔树枝状分子NH2-G1-(NO2)2和NH2-G2-(NO2)4.用傅里叶变换红外光谱跟踪了整个固定相合成过程.苯乙炔树枝状分子的紫外-可见吸收光谱呈现出规律性变化. 相似文献
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Reaction of [(μ-SCH2)2NPh]Fe2(CO)6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [(μ-SCH2)2NPh]Fe2(CO)5(Ph2PCH2PPh2)(1)in 78% yield.The new complex 1 was characterized by elemental analysis,spectroscopy and X-ray crys-tallography.It crystallizes in triclinic,space group P1 with a = 10.832(2),b = 12.003(2),c = 15.579(3),V = 1785.6(6)3,Z = 2,C32H26Fe2NO5PS2,Mr = 819.40,Dc = 1.524 g/cm3,μ(MoKα)= 1.064 mm-1,F(000)= 840,T = 113(2)K,the final R = 0.0543 and wR = 0.1218 for 6203 observed reflections(I > 2σ(I)).The Ph2PCH2PPh2 ligand resides in an axial position of the square-pyramidal coordination sphere of the Fe atom and trans to the benzene ring in order to reduce the steric repulsion between Ph2PCH2PPh2 and the benzene ring. 相似文献
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用溶剂热方法合成了2个新的3d-4f异金属四核簇合物:[Zn2Ln2(salen)2(CO2PyCH2O)2(MeOH)2](ClO4)2·2MeOH(Ln=Dy(1),Tb(2);H2salen=N,N'-双(3-甲氧基水杨基)-1,3-二氨基丙烷;HCO2PyCH2OH=6-羧基吡啶-2-甲醇)。它们是由锌(Ⅱ)Schiff碱构筑模块和6-羧基吡啶-2-甲醇辅助配体组装而成的Zn-Ln2-Zn型簇合物。磁性测量表明稀土离子间存在铁磁性相互作用。Zn2Dy2配合物1在2 000 Oe直流磁场下显示出磁弛豫行为;而Zn2Tb2配合物2不但有磁场导致的磁弛豫行为,而且还具有荧光性质。 相似文献
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Sellmann D Hille A Rösler A Heinemann FW Moll M Brehm G Schneider S Reiher M Hess BA Bauer W 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(4):819-830
In the quest for low-molecular-weight metal sulfur complexes that bind nitrogenase-relevant small molecules and can serve as model complexes for nitrogenase, compounds with the [Ru(PiPr(3))('N(2)Me(2)S(2)')] fragment were found ('N(2)Me(2)S(2)'(2-)=1,2-ethanediamine-N,N'-dimethyl-N,N'-bis(2-benzenethiolate)(2-)). This fragment enabled the synthesis of a first series of chiral metal sulfur complexes, [Ru(L)(PiPr(3))('N(2)Me(2)S(2)')] with L=N(2), N(2)H(2), N(2)H(4), and NH(3), that meet the biological constraint of forming under mild conditions. The reaction of [Ru(NCCH(3))(PiPr(3))('N(2)Me(2)S(2)')] (1) with NH(3) gave the ammonia complex [Ru(NH(3))(PiPr(3))('N(2)Me(2)S(2)')] (4), which readily exchanged NH(3) for N(2) to yield the mononuclear dinitrogen complex [Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')] (2) in almost quantitative yield. Complex 2, obtained by this new efficient synthesis, was the starting material for the synthesis of dinuclear (R,R)- and (S,S)-[micro-N(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] ((R,R)-/(S,S)-3). (Both 2 and 3 have been reported previously.) The as-yet inexplicable behavior of complex 3 to form also the R,S isomer in solution has been revealed by DFT calculations and (2)D NMR spectroscopy studies. The reaction of 1 or 2 with anhydrous hydrazine yielded the hydrazine complex [Ru(N(2)H(4))(PiPr(3))('N(2)Me(2)S(2)')] (6), which is a highly reactive intermediate. Disproportionation of 6 resulted in the formation of mononuclear diazene complexes, the ammonia complex 4, and finally the dinuclear diazene complex [micro-N(2)H(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] (5). Dinuclear complex 5 could also be obtained directly in an independent synthesis from 1 and N(2)H(2), which was generated in situ by acidolysis of K(2)N(2)(CO(2))(2). Treatment of 6 with CH(2)Cl(2), however, formed a chloromethylated diazene species [[Ru(PiPr(3))('N(2)Me(2)S(2)')]-micro-N(2)H(2)[Ru(Cl)('N(2)Me(2)S(2)CH(2)Cl')]] (9) ('N(2)Me(2)S(2)CH(2)Cl'(2-) =1,2-ethanediamine-N,N'-dimethyl-N-(2-benzenethiolate)(1-)-N'-(2-benzenechloromethylthioether)(1-)]. The molecular structures of 4, 5, and 9 were determined by X-ray crystal structure analysis, and the labile N(2)H(4) complex 6 was characterized by NMR spectroscopy. 相似文献