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高分子担载水杨醛希夫碱钴配合物催化分子氧氧化环己烯性能研究 总被引:5,自引:0,他引:5
合成了聚苯乙烯担载的酪氨酸水杨醛希夫碱钴配合物,并研究了该高分子金属配合物对分子氧氧化环己烯的催化性能.探讨了反应温度、添加剂及反应时间对环己烯转化率和产物选择性的影响.结果表明,70℃时,以微量醋酸为添加剂,在催化剂的催化作用下,以常压氧气氧化环己烯,得到烯丙基位的氧化产物环己烯醇、环己烯酮和中间产物环己烯过氧化氢.催化剂经五次循环使用仍具有较高的催化活性.环己烯在该高分子配合物作用下的催化氧化遵循一个自由基反应历程,与经典的Haber-Weiss历程相一致. 相似文献
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手性胺—铜配合物的合成及其在菊酸不对称合成中的应用 总被引:6,自引:0,他引:6
报导了新型希夫碱-铜配合物的合成,及其对菊酸不对称合成的催化诱导效应,用降解脱氢松香胺和水杨醛反应,形成希夫碱,再与醋酸铜反应,制行希夫碱-铜配合物。将该配合物作为手性催化剂,催化重氮乙酸乙酯及重氮乙酸冰片酯与2,5-二甲基-2,4-己二烯合成菊酸的反应,讨论了重饩 相似文献
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Schiff碱配合物结构对其催化氧化性能的影响 总被引:3,自引:0,他引:3
水杨醛缩二胺类双Schif碱配合物,在可逆吸附氧分子和催化氧化性能等方面的研究已有不少报道[1-3]。Schif碱配合物在均相氧化反应中早有应用,但作为异丙苯均相氧化反应的催化剂的报道则很少[4]。已有的研究结果表明,Schif碱配合物结构对在催化氧... 相似文献
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键联聚乙二醇高分子担载锰(Ⅲ)卟啉的合成及催化烯烃环氧化反应性… 总被引:2,自引:1,他引:2
本文研究了键联聚乙二醇高分子担载锰(Ⅲ)卟啉的合成,以及在CH2Cl2/H2O两相体系中催化苯乙烯环氧化反应的性能,探索了催化反应体系中溶液pH值、NaOCl浓度、轴向配体及相转移催化剂对催化反应的影响。结果说明键联聚乙二醇高分子担载锰(Ⅲ)卟啉是烯烃环氧化反应的一种有效催化剂,其中聚乙二醇链可以络合Na,使OCl富集于金属卟啉周围,起到较好的相转移催化作用。在催化反应的各影响因素中,水相pH值对 相似文献
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Pd(OAc)2/FePc催化环己烯氧化合成环己酮的研究 总被引:6,自引:0,他引:6
考察了几种Fe-大环配合物与Pd(OAc)2组成的双组分催化体系,在乙腈酸性水溶液中环己烯经合成环己酮的催化活性,实验结果表明,其中以酞菁失(FePc)与Pd(OAc)2组成的催化体系活性最高,而FeTPPCl与Pd(OAc)2催化体系,虽然催化活性较高,但催化剂的稳定性较低,各种因素对Pd(OAc)2/FePc催化活催化影响的研究结果指出,在无水和酸存在的非水溶液中,Pd(OAc)2/FePc对 相似文献
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Chitosan, a natural polymer, bound Schiff base copper complexes CT‐She‐Cu, CT‐o‐Bel‐Cu, CT‐m‐Bel‐Cu were prepared and characterize by inductively coupled plasma (ICP), FT‐IR and X‐ray photoelectron spectroscopy (XPS). Their catalytic activity in the oxidation of cyclohexene with molecular oxygen was studied. All the complexes have catalytic activity and the main oxidation products are 2‐cyclohexene‐ol, 2‐cyclohexene‐one and cyclohexene hydroperoxide, which were measured by gas chromatography/mass spectroscopy (GC/MS) and GC/IR. CT‐m‐Bel‐Cu was selected to study the influence of reaction temperature, amount of catalyst and additives such as acid and base on the oxidation of cyclohexene systematically. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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环己烯可控选择性催化氧化的最新进展(英文) 总被引:2,自引:0,他引:2
环己烯是一种价格低廉易得的大宗化工原料,通常由苯选择性加氢来合成.该化合物虽然分子结构简单,但却有两个不同的反应位点.随着反应所发生的位点与反应深度的不同,环己烯的氧化反应可生成一系列不同氧化程度与官能团的产物的混合物.环己烯双键的氧化反应,可生成环氧环己烷,而环氧环己烷进一步水解,则生成1,2-环己二醇,其中,随着使用不同催化剂导致的反应机理差异,产物可分别为顺式或反式结构.在强氧化剂作用下,环己烯双键充分氧化,可生成己二酸.环己烯烯丙基C-H键氧化,则可随着反应深度的不同分别生成2-环己烯醇与2-环己烯酮.上述环己烯氧化产物都是重要的有机化工中间体.其中,环氧环己烷是农药杀螨剂的主要原料,也用作合成表面活性剂、橡胶助剂等有用产品;1,2-环己二醇可用于合成化工中间体邻苯二酚;环己烯醇与环己烯酮是生产除草剂、香水、药物的原料;己二酸则是合成重要产品尼龙-6,6的原料.因此,随着市场需求的变化,对环己烯氧化反应进行选择性控制,提高其中某种产物的选择性,是重要的化工合成技术,有着巨大的应用潜力;从而控制反应历程与深度是有机化工合成工艺研究中最具有挑战性的研究课题之一,有很好的科学意义.目前,人们对环己烯的选择性控制氧化反应已进行了广泛的研究.该反应可使用金属催化剂,包括铁、钴、镍、锰、铬、钒、钨、铜、钛、金、银、铋、锇、钼、镉等;也可以使用无金属催化剂如磺酸、2,2,2-三氟苯乙酮、类石墨相碳化氮(g-C3N4)等.反应可使用化学氧化剂,如间氯过氧苯甲酸、醋酸碘苯、过氧叔丁醇等,也可使用更加清洁的过氧化氢、分子氧.研究表明,催化剂的种类、用量,以及反应溶剂、温度、氧化剂等一系列外在条件,可以影响环己烯氧化反应的选择性.本文以反应所使用的氧化剂归类,总结了该课题的最新研究进展,以期对从事环己烯可控选择性氧化的学术与工业研究人员有所帮助. 相似文献
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A thermosensitive nanocatalyst was prepared in the reaction of water-soluble iron(III) porphyrins and thermosensitive polymeric nanospheres with a core-shell structure; its catalytic activity in cyclohexene oxidation by iodosylbenzene was dependent markedly on reaction temperatures in aqueous solution. 相似文献
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缺位Dawson型K10Na2H2P2W16O60在环己烯氧化中的催化作用 总被引:1,自引:0,他引:1
合成了二缺位杂多化合物K10Na2H2P2W16O60·18H2O,用IR、UV-vis、XRD及TG表征了其结构,考察了该化合物在过氧化氢氧化环己烯反应中的催化作用.研究结果表明,溶剂种类和反应温度对二缺位杂多化合物的催化性能有显著的影响,在叔丁醇中主要生成环己烯酮,在丙酮中主要生成环己二醇.在乙腈中主要生成环氧环己烷,其选择性随着反应温度升高和催化剂用量增加而降低,环己烯酮的选择性则逐步升高.催化剂与产物可通过温控固-液相分离,可以重复使用. 相似文献
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A facile preparation method of nano-CuO catalysts, assembled in the hollow nanotube of halloysite nanotubes(HNTs), was developed. The characterizations of XRD, TEM, SEM, BET, XRF and FT-IR were used to analyze the structure and properties of the nano-CuO/HNT loaded catalyst. The XRD patterns indicated that the CuO nanoparticles on HNTs were monoclinic phase. The TEM-EDX and SEM images confirmed that most of nano-CuO catalysts with the crystal size of ca. 20 nm were assembled into the hollow nanotube of HNTs. The catalytic performance of the nano-CuO/HNT catalysts was evaluated by using selective oxidation of cyclohexene. The reaction temperature and recycling times were investigated. The results reveal that the nano-CuO/HNT catalysts exhibit an excellent catalytic oxidation performance for selective oxidation of cyclohexene to 2-cyclohexene-1-one. 相似文献
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A series of iron(Ⅲ) chlorophyllins was prepared from silkworm excrement crude chlorophyll extract as a raw material. Aerobic oxidation of cyclohexene by using the prepared iron(Ⅲ) chlorophyllins as biomimetic catalysts was studied under atmospheric pressure in the absence of reducing agent and solvent. The results indicate that chlorophyll iron porphyrins have better catalytic performance than the industrial-applied iron tetraphenylporphyrin and cobalt tetraphenylporphyrin, and possess a higher selectivity for 2-cyclohexen-1-one. The smaller the polarity of iron(Ⅲ) chlorophyllin's ligand is, the easier the catalytic oxidation of cyclohexene will be. Esterification products of iron(Ⅲ) chlorophyllins can catalyze the oxidation of cyclohexene better than non-esterified iron(Ⅲ) chlorophyllins, and therefore show a higher conversion of cyclohexene and a higher selectivity for 2-cyclohexen-1-one than the non-esterified ones. Among the six synthesized iron(Ⅲ) chlorophyllin catalysts, iron(Ⅲ) methyl-pyropheophorbide-a is the best biomimetic catalyst for the highest conversion of cyclohexene. The influences of catalyst's substituent, polarity and ring structure on the catalytic performance were discussed. The catalytic performance of iron(Ⅲ) chlorophyllins improves with decreasing polarity, increasing conjugated degree of porphyrin's ring or enhancing chlorophyllins' stability. Possible mechanism of cyclohexene aerobic oxidation catalyzed by iron(Ⅲ) chlorophyllins was also discussed. 相似文献
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Mohd. Bismillah Ansari Eko Adi Prasetyanto Jun Lee Sang-Eon Park 《Research on Chemical Intermediates》2010,36(6-7):677-684
Synthesis of melamine glyoxal resin involves a catalyst-free, one pot reaction between melamine and glyoxal in DMF. The synthesized resins have a similar morphological arrangement to that of layered materials as depicted by their XRD pattern and Raman spectra. The catalytic behavior of melamine glyoxal resin (MGR) have been studied in allylic oxidation of cyclohexene and simultaneous Michael addition. The MGR/solvent/O2 oxidant system can be regarded as a metal-free, additive-free, cost-effective and environmentally benign catalytic system. The oxidative behavior of MGR is attributed to its ability to generate in situ organic peroxide species during the course of reaction. Generation of peroxide species is confirmed by the KI/starch test and further confirmed by the complete suppression effect of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) over oxidation. The activity for Michael addition can be attributed to the presence of a higher content of nitrogen atoms, which serves as the active site. In oxidation, 28.1% conversion of cyclohexene with 37.19 and 62.81% selectivities for cyclohexenol and cyclohexenone were observed, respectively. In consecutive oxidation and oxy-Michael addition, 31.5% conversion of cyclohexene was observed with selectivities of 61.6% for cyclohexenone and 38.4% for alkoxy product. 相似文献
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Catalytic properties of copper(II) tricyclic chelate compounds based on enamino ketone of 3-acetyl-2,4-pentanedione and 1,6-hexametylenediamine
fixed on NaY and CaA zeolites by the methods of topological and topologically-anchor retention, respectively, were compared.
The mode of fixation of chelates on a support affects the character of the liquid-phase catalytic oxidation of cyclohexene
by molecular oxygen. At the topological fixation by a steric retention of a chelate compound in a large cavity of NaY zeolite,
the reaction rate related to one reaction center of a metal complex is not proportional to the filling degree that points
to inaccessibility for a substrate of catalyst molecules localized in inner cavities of crystallites. In an alternative mode
of the catalyst topologically-anchor fixation, when only a ligand fragment is held in CaA zeolite, and catalytically active
metal center is turned to the side of the reaction medium, the linear dependence of the cyclohexene oxidation rate on the
amount of the chelate on the support is retained within the whole studied range of the surface catalyst concentrations. The
catalytic activity of the topologically-anchor fixed Cu(II) chelate compound coincides with its activity in the zeolite absence,
which points to a pseudo-homogeneous mode of cyclohexene oxidation. At topologically-anchor fixation of a Cu(II) chelate compound
on CaA zeolite diffusion limitations characteristic for the fixation by steric retention are completely eliminated. 相似文献