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1.
以环氧氯丙烷(1)和NaHSO3为原料,Na2SO3为引发剂,乙二胺四乙酸二钠(EDTA2Na)为络合增效剂,经酸催化开环反应合成了磺酸型两性表面活性剂中间体--3-氯-2-羟基丙磺酸钠(2),其结构经1H NMR, IR和ESI-MS确证。在最佳反应条件[1 0.55 mol, n(NaHSO3): n(Na2SO3): n(EDTA2Na): n(H2O)=1.00 : 0.04 : 0.01 : 9.50, 1的滴加时间15 min,在适宜的转速(前期100 rpm, 后期300 rpm)下,于70 ℃(浴温)反应1.25 h]下合成的2,收率81.55%。并对反应机理进行了推测。 相似文献
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合成了3种BINOL双酰胺(Ⅰ~Ⅲ),其结构经1H NMR, 13C NMR, HR-MS(ESI)和元素分析确证。研究了I~III对取代吲哚和硝基烯烃的Friedel-Crafts烷基化反应的催化性能,并对反应条件进行了优化。结果表明:在最优条件(CH2Cl2为溶剂,Ⅰ为催化剂,于40 ℃反应12 h)下,吲哚及取代吲哚与硝基烯烃均能有效的进行Friedel-Crafts烷基化反应,收率和ee值最高可达88%和90%。 相似文献
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以过渡金属甲基磺酸盐[Mn(CH3SO3)2·2H2O, Cu(CH3SO3)2·4H2O, Co(CH3SO3)2·4H2O和Zn(CH3SO3)2·4H2O]为催化剂,在室温条件下催化醇的四氢吡喃化反应,并对反应条件进行了优化。结果表明:当醇用量为30 mmol,醇和3,4-二氢吡喃摩尔比为1.0 :1.1,甲基磺酸盐用量为1 mmol,二氯甲烷20 mL时,可高效催化醇的四氢吡喃化反应。与路易斯酸催化活性相比,过渡金属甲基磺酸盐催化醇的四氢吡喃化反应效果最好,催化酚的效果较差。用Mn(CH3SO3)2·2H2O和Cu(CH3SO3)2·4H2O催化正丁醇的四氢吡喃化反应,重复使用5次,收率分别为89%和92%。 相似文献
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以含磺酸基离子液体1-(4-磺酸基)丁基-3-甲基咪唑四氟硼酸盐([4-sulfbmim][BF4])为酸性催化剂,由乙缩醛和苯甲醇合成了叶青素。 采用正交实验方法考察了合成条件的影响,固定反应温度为20 ℃条件下,确定优化合成条件为:n(苯甲醇)∶n(乙缩醛)=1∶8,反应时间60 min,催化剂用量为每摩尔苯甲醇4 g,产率为92.2%。 与H2SO4催化剂相比[4-sulfbmim][BF4]的催化活性相对较弱,但综合效果优于H2SO4。 [4-sulfbmim][BF4]循环使用6次,催化活性基本不变。 相似文献
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The enantioselective epoxidation of olefin by MnII(R,R-PMCP)(OTf)2, H2O2 and H2SO4 was explored by DFT calculations and experiments. Theoretical results suggest that [MnV(O)(R,R-PMCP)(SO4)]+species with a triplet ground spin state serves as the active species for the olefin epoxidation. It can be generated by the H2SO4 assisted O-O heterolysis of MnIII(OOH) species. MnIII-persulfate is also involve... 相似文献
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The enantioselective epoxidation of olefin by MnII(R,R-PMCP)(OTf)2, H2O2 and H2SO4 was explored by DFT calculations and experiments. Theoretical results suggest that [MnV(O)(R,R-PMCP)(SO4)]+species with a triplet ground spin state serves as the active species for the olefin epoxidation. It can be generated by the H2SO4 assisted O-O heterolysis of MnIII(OOH) species. MnIII-persulfate is also involve... 相似文献
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研究了H3PO4-BF3/ZrO2及H3PO4-BF3-H2SO4/ZrO2催化剂对异构烷烃烷基化反应的催化作用。就载体的焙烧温度、活性组分的浓度、BF3及H2SO4的添加及反应温度对催化剂活性的影响进行了较为详尽的研究。 相似文献
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环境友好催化剂TiSiW_(12)O_(40j)/TiO_2的制备及其催化性能研究 总被引:22,自引:0,他引:22
制备了新型固载杂多酸盐TiSiW_(12)O_(40)/TiO_2环境友好催化剂,并以丁酸 丁酯的合成作为探针反应,系统考察了原料H_4SiW_(12)O_(40)·xH_2O与TiO_2摩 尔比、焙烧温度、焙烧时间等制备条件对TiSiW_(12)O_(40)/TiO_2催化活性的影响 。实验表明:制备催化剂的适宜条件为原料H_4SiW_(12)O_(40)·xH_2O与TiO_2摩 尔比为0.47,焙烧温度为350 ℃,焙烧时间为3.0 h。利用该条件下制备的催化剂 TiSiW_(12)O_(40)/TiO_2合成了丁酸丁酯正丁醇与正丁醇的投料摩尔比n(醇):n(酸 ) = 1.3:1,催化剂的用量占反应物总投料质量的1.3%,反应时间为1 h,丁酸丁酯 的产率为97.2%。该催化剂TiSiW_(12)O_(40)/TiO_2用于制备其它丁酸酯类(如乙 酯、丙酯、戊酯、异戊酯)时同样取得了好的结果。 相似文献
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Co(III)离子在二氧化铅电极上的阳极形成 总被引:2,自引:1,他引:2
文献上曾报导过Co(Ⅱ)离子具有加速PbO_2电极上氧阳极析出过程的作用,并表明当Co(Ⅱ)离子存在时,氧的析出过程有可能通过表面吸附的高价钴氧化物氧化水分子而形成.本文通过浓硫酸溶液中Co(Ⅱ)阳极氧化为Co(Ⅲ)以及O_2阳极析出动力学的研究,表明了O_2的析出和Co(Ⅲ)的形成是通过吸附在电极表面的高价钴(Ⅳ)的OH 基配合物分别氧化水分子和Co(Ⅱ)离子形成的,它与Cr(Ⅲ)、Mn(Ⅱ)离子的阳极氧化过程相类似,而不是通过Co(Ⅱ)离子直接放电形成的.本文利用文献所述的研究方法.在固定硫酸浓度(3.4mol·kg~(-1))下,研究CoSO_4浓度(0.05—0.35mol·drn~(-3))对于O_2和Co(Ⅲ)阳极形成过程分别的影响.在固定CoSO_4(0.2mol· 相似文献
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采用等温蒸发法研究了五元体系Li~+,K~+//CO_3~(2-),SO_4~(2-),B_4O_7~(2-) -H_2O在288 K时的介稳相平衡关系,测定了该五元体系在288 K条件下的介稳平衡的溶解度和溶液密度,根据实验数据绘制了相应的介稳平衡相图和水图,相平衡研究结果表明该五元体系介稳相平衡中有复盐K_2SO_4·Li_2SO_4生成,其介稳相图(Li_2CO_3饱和)有4个共饱和点,9条单变量曲线,6个Li_2CO_3饱和的结晶区分别为LiBO_2·8H_2O,K_28_4O_7·4H_2O,K_2CO_3·3/2H_2O,K_2SO_4,Li_2SO_4·H_2O和复盐K_2SO_4·Li_2SO_4. 相似文献
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Density functional theory was used at the B3LYP/6-311++G(d,p) level of theory to study the hydrates of 2NH3:H2SO4:nH2O for n = 0~4. Neutrals of the most stable clusters, when n = 0 and 1, spontaneously formed and were determined to be hydrogen-bonded molecular complexes of monomeric species. Double ions (clusters containing a NH4+ cation and a HSO4- anion) or even ternary ions (clusters with two NH4+ cations and one SO42- anion) spontaneously formed in the most stable clusters of 2NH3:H2SO4:nH2O (n = 2, 3, 4). The energetics of binding and incremental association was also calculated. Double ions are not energetically favorable until 2NH3:H2SO4:2H2O because of the about equal free energies for forming the neutral (the most stable) and double ion (the second stable) isomers. The free energy of incremental association from free H2O and 2NH3:H2SO4:nH2O has a maximum at n = 2 at room temperature with ΔG ≈ -2 kcal/mol. The comparison of incremental association energies between 2NH3:H2SO4:nH2O, NH3:H2SO4:nH2O and H2SO4:nH2O clusters revealed that NH3 plays an important role in the atmospheric particle nucleation. 相似文献
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以二丙酮醇为有机物Ce3+为催化剂的BR型化学振荡反应的研究 总被引:1,自引:1,他引:1
The oscillatary behavior of diacetone alcohol(DA)-KIO_3-H_2O_2-H_2SO_4-Ce~(3+) system has been studied.The system may oscillate in the concentration ranges of H_2SO_4 0.11—0.24, KIO_3 0.019—0.048; Ce~(3+) 5.95×10~(-4)—3.57×10~(-3), DA 0.4—3.22 and H_2O_2 0.40—1.99 mol·dm~(-3) respectively. Using Hg_2SO_4 electrode as the reference electrode, the potential of I~- and the redox potential show oscillatary wave behavior in XWT balance recorder. According to our expreimental results, We may said seen that ... 相似文献
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SO2-4/ZrO2/Fe3O4/Al2O3磁性固体超强酸的制备与表征 总被引:5,自引:0,他引:5
用化学共沉淀法制备了一系列SO2-4/ZrO2/Fe3O4/Al2O3磁性固体超强酸, 利用XRD、IR、TG-DSC、VSM、TEM及HRTEM等手段对样品结构进行了表征. 结果表明, 引入一定量的Fe3O4和Al2O3有利于四方晶相ZrO2(t)结构的稳定;Fe3O4超细粒子的引入, 使固体超强酸具备了超顺磁性;HRTEM 结果显示ZrO2晶体生长趋向于ZrO2(t)的[101]方向,其(101)晶面间距为d(101)=0.29 nm, 与XRD 衍射结果一致. Hammett 指示剂测得样品SZA-20-200-800酸强度(H0<-13.8)最强, 酸性大于浓硫酸(H0=-11.9). 相似文献
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全氟辛基磺酸酸度函数H0的测定 总被引:2,自引:1,他引:2
It is reported in this paper that the acidity function H_0 of perfluorooctanesulfonic acid (POSA) is -12.11±0.03, which was measured first time by ~1H NMR method, in term of the α-H chemical shifts of the acid-ether systems, using 98% to 100% H_2SO_4 as reference standards. This method provides a new procedure for measuring the H_0 value of solid perfluoroalkanesulfonie acid C_nH_(2n+1)SO_3H(n>7). 相似文献
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磷钼钒杂多酸在苯直接羟化反应中的催化作用—H2O2活化机理的探讨 总被引:4,自引:0,他引:4
磷铝钒杂多酸(H_(3+n)PMo_(12-n)V_nO_(40))+H_2O_2体系在苯直接羟化反应中的催化行为和众所周知的Fenton试剂(Fe~(++)+H_2O_2)完全不同。酚是羟化的唯一产物; H_2O_2分解动力学曲线呈“S”型。电子光谱数据表明, H_2O_2分解过程形成两种中间络合物。以此为依据, 提出了磷钼钒杂多酸对H_2O_2活化和苯羟化的反应机理, 认为杂多酸阴离子上的钒离子先和H_2O_2形成过渡的金属过酸型络合物, 然后再按自催化机理转化成金属过氧络合物, 后者在反应中起活化H_2O_2和羟化苯的活性种作用。按此反应机理所得的动力学公式可以对实验结果作出比较合理的解释。 相似文献
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Rare-earth compound solid superacid SO42-/TiO2/La3+ was prepared. Its catalytic activity was examined under different synthetic conditions for the esterification of propanoic acid and n-butyl alcohol as probing reaction. The optimum conditions were also found, which were the pH=8, the depositing time was 24 h, the mass fraction of La(NO3)3 used in solid superacid was 5%, the concentration of H2SO4 was 1.25 mol/L, the soaking time in H2SO4 was 16 h and the calcining temperature was 500 °C. The ethyl oleate was synthesized from oleic acid and ethanol in the presence of SO42-/TiO2/La3+. The optimum reaction conditions were obtained which were the reaction time was 6 h, molar ratio of oleic acid to ethanol was 1:4 and the mass fraction of catalyst was 4%. 相似文献