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本文首次利用碳基钴簇合物PhPCo_3(CO)_9催化剂,在常压和-20℃-0℃,用苯乙烯和重氮乙酸乙酯进行环丙烷化反应,合成了菊酸酯,重氮乙酸乙酯可全部转化,酯的选择性可达85%。产物经减压分馏后,由IR和 ̄1HNMR分析,确证了产物为菊酸酯,表明了羰基钴簇合物对苯乙烯的环丙烷化反应有良好的催化性能,为四面体异核簇合物用于不对称催化反应打下了基础。 相似文献
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研究了以铜化合物催化重氮乙酸乙酯与烯烃的环丙烷化反应,首次计算了反应关键中间体铜-卡宾的环丙烷化选择性P及该中间体的解离常数K,结果表明:1.反应体系中可能存在着铜-卡宾与游离卡宾的平衡;2.P、K与所用的催化剂有关。使用不同的催化剂,温度对反应选择性的影响也不同,对以上结果进行了理论探讨。 相似文献
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四甲基乙烯环丙烷化反应的催化研究 总被引:2,自引:0,他引:2
烯烃和重氮乙酸酯(RDA)在光照、加热或催化剂作用下反应生成的环丙烷羧酸酯是合成拟除虫菊酯的重要中间体。铜、铑等金属的化合物作为催化剂在这类反应中得到了广泛应用。对RDA和四甲基乙烯TME的环丙烷化反应,曾以CuSO_4、Cu(acac)_2、 相似文献
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手性铜(Ⅱ)-席夫碱配合物催化苯乙烯不对称环丙烷化反应 总被引:22,自引:0,他引:22
Twelve chiral copper(Ⅱ) Schiff base complexes, derived from (R) (+) 2 amino 1,1 diaryl 1 propanol with substituted salicylaldehydes, were examined as a catalyst for asymmetric cyclopropanation of styrene with ethyl diazoacetate. It was found that the substituents at 3 and 5 positions of salicylaldehyde in the ligands had great effects on catalytic activity and enantioselectivity of the catalyst. The complex with strong electron withdrawing group (NO 2) at 5 position and the smallest stereo hinder (H) at 3 position of salicylaldehyde showed highly catalytic activity and enantioselectivity, up to ee =87 4% for trans and ee =82 8% for cis isomers respectively, and the ratio 39/61 of cis to trans isomers was obtained at 40 ℃ with 1,2 dichloroethane as solvent. 相似文献
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双烷基钪配合物LSc(CH2SiMe3)2(L=(2,6-iPr2C6H3)NC(Me)CHPPh2N(2,6-Me2C6H3))在助催化剂[Ph3C][B(C6F5)4]的作用下能够高活性地催化乙烯和丙烯共聚.在反应温度30℃和乙烯与丙烯常压(1.0×105Pa)下聚合,共聚活性能够达到7.5×105g(PE)mol-1h-1(105Pa)-1.单体的竞聚率分别为rE=29.75和rP=0.015.13C-NMR和DSC分析表明所得到的乙丙共聚物是弹性体,且丙烯单体无规分布在共聚物链中. 相似文献
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在乙醇存在下,镍、钴、锌在pH 6.6六胺缓冲溶液中可与显色剂2-(6-甲基-2-苯并噻唑偶氮)-5-二乙氨基苯甲酸(MBTAEB)形成稳定的配合物,其表观摩尔吸光系数分别为:εN64i6 nm=1.49×105L.mol-1.cm-1;εC65o0 nm=1.32×105L.mol-1.cm-1;εZ63n0 nm=7.7×104L.mol-1.cm-1。但三种络合物的吸收光谱重叠相互干扰,应用多波长线性回归法,可在三离子共存下单独测定。方法简单、快速、灵敏度高,可不经分离同时测定三种离子的含量。 相似文献
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X射线荧光光谱法测定催化剂中的铁、镍、铜、钒 总被引:7,自引:0,他引:7
介绍用X射线荧光光谱法测定催化裂化催化剂中重金属Fe、Ni、Cu、N含量的分析方法。以未使用过的催化剂为载体配制标准样品,使标准样品与样品的基体基本一致,减少了基体效应的影响。待测元素的线性范围分别为:Fe0.30%~2.50%,Ni0.10%~1.20%,Cu0.02%~0.20%,V0.05%~0.30%,相关系数均为0.9999,测定结果的相对标准偏差小于2%。该方法的测定结果与原子吸收法的测定结果相吻合。 相似文献
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《Journal of Coordination Chemistry》2012,65(1):113-117
Abstract The oxovanadium(IV) complex of the ligand, N,N'-bis-(salicylidene)-1,1-(dimethyl)ethylenediamine, has been prepared. It has a magnetic moment of 1.76 B.M., which is almost invariant over a range of temperature. The electron paramagnetic resonance spectrum of the powder has been measured at 296° and 80°K, while that of the solution was measured at 296°K (go ≈ 1.97 and A0 ≈ 90 × 10?4 cm?1). The magnetic moment of the complex agrees with that calculated from the paramagnetic resonance g values taken at 80°K. Furthermore, the complex has been characterized by mass spectra, infra-red, ultra-violet and visible spectra, conductivity, osmometry and polarimetry. All evidence suggests that the complex is a tetragonal-pyramid. 相似文献
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The N,N'-(phenyl-2-pyridinylmethylene)-3,3',5,5'-tetramethylbenzidine and its dimeric Co(Ⅱ)and Ni(Ⅱ) complexes were synthesized.The organic compound was characterized by elemental analyses,IR and NMR spectra,while the bimetal complexes were determined by elemental analyses,IR spectra as well as the single-crystal X-ray diffraction.The nickel complex showed high activity for ethylene polymerization and its cobalt analogue showed negligible active in ethylene activation. 相似文献
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热处理对Co(Ni)-Mo/Al2O3催化剂加氢脱硫活性的影响 总被引:9,自引:0,他引:9
介绍了硫化Co-Mo/Al2O3催化剂的热处理方法及其结果。实验表明,硫化催化剂经热处理后,加氢脱硫活性明显增加,以塞吩转化率表示的催化活性随处理温度升高而变化,在450℃时观察到催化活性的极大值。 相似文献
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系统地研究了γ-Al2O3催化剂中杂质Fe和Na对甲硫醚合成的催化行为的影响。随着Fe含量的增大,甲醇分解反应加剧,硫醇产率增高,甲硫醚产率下降;Na含量越低,甲醇分解率越高。Na含量在0.2%-0.4%时,甲硫醚产率最高,甲硫醇生成率最高;Na含量进一步增大时,甲醇双分子脱水生成甲硫醚的量增加,甲硫醇产率增高,生成甲硫醚的选择性下降。 相似文献