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Self-addn. of iodide to pyridinium nucleus can take place for 2-chloro-1-dodecyl pyridinium iodide (CDPI) in CH2Cl2 upon irradiation The structure of product isolated was shown to be the para-isomer with spectroscopic methods. From electron spectroscopic results, Kosower postulated that the pyridinium iodide can exist in the form of self-addn. product through intermediates of charge-transfer complex and tight free radical pair, but in the ground state the balance trends to ionic form, therefore the addition product was not isolated yet. The fact that we were able to isolate a stable self-addn. product I from CDPI, might be attributed to the existence of chlorine causing the decrease of electronic d. at nucleus thus stabilizing the I-C bond. The fact that isolation of addition product provides a more direct evidence for the charge-transfer mechanism in the action of Kosower polarity probes. 相似文献
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通过甲酰基二茂铁与取代水杨醛和氨反应, 直接合成了含一个二茂铁的混合三聚产物, N,N'-二[2-羟基-5-取代苄烯]二茂铁甲二胺. 茂环上碳原子的化学位移^1^3C NMR与苯环上R取代基的Hammett常数之间存在着很好的线性关系. 循环伏安法测出的E1/2也与hammett常数之间存在着很好的线性关系. 通过混合三聚反应, 也合成了另一类含两个二茂铁化合物, N,N'-二[二茂铁甲烯]-2-羟基-5-特丁基苯甲二胺. ^1H及^1^3C NMR表明, 分子内由于氢键和立体效应的影响, 导致两个茂环上的化学环境不等性. 相似文献
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本文合成了两个新型双核配合物, [Cu(Samen)Co(L)2]和[Cu(Sampn)Co(L)2], Samen^4^-表示N,N'-双水杨酰代乙二胺根阴离子,Sampn^4^-表示N,N'-1,2-双水杨酰代丙二胺根阴离子, L表示5-硝基-1,10-菲咯啉(NO2-Phen)。经元素分析, IR和电子光谱等推定配合物具有酚氧桥结构,Cu(II)及Co(II)的配位环境分别为平面四方及畸变八面体构型。测定了配合物(4-300K)的变温磁化率, 并用最小二乘法和自旋Hamiltonian算符,H=2JS1.S2-DSzl导出的磁方程拟合, 求得交换参数为J=-4.39(Samen)和-3.59cm^-^1(Sampn), 表明两个Cu(II)-Co(II)双核配合物中有弱的反铁磁性超交换相互作用。 相似文献
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Nd(OR)3-nCln-AlEt3催化体系对丁二烯的聚合 I.聚合的一般规律 总被引:3,自引:0,他引:3
Homopolymerization of butadiene has been carried out with a new series of binary catalyst system Nd(OR)3-nCln-AlEt3 and the catalytic activity as well as the microstructure of the resulting polymer have been studied. The results indicate that the stereospecificity of the polybutadiene obtained with these beinary catalyst system (when n=2) is similar to that prepared with thernary system Nd(OR)3-Al2Et3Cl3-AlEt3, yet the catalytic activity of the former is somewhat higher. Hence, it is possible that the present simpler binary system is more preferable to be applied than the ternary. System in butadiene polymerization. 相似文献
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近年来, 我们在研究含氟烯烃和烷烃的红外激光诱导氧化和氯化反应的基础上, 深入研究了红外激光诱导卤代烷烃的脱卤化氢并生成: CF2卡宾和:CFCF3卡宾的反应[1-4]以往的研究往往是根据反应产物推论反应机理, 认为在反应过程中存在着卡宾中间体,但在实验中未能直接检测到. Kakimoto[5,6]曾报道过在流动体系中测到了.F+CH3F和.F+CH3Cl反应中:CHF和:CHCl的激光荧光激发谱, 但没有讨论卡宾形成的机理.Hirota[7]在讨论.F+CH3F反应时, 认为:CHF可能由攫氢过程产生而对于.F+CH3Cl反应同时生成:CHF和:CHCl未做说明. 本实验中用扩散分子束代替了流动反应体系, 从而大大减少了产物和反应物气体分子间的猝灭过程, 获得了信噪比大而清晰的图谱, 由此确证了:CHF和:CHCl的存在, 说明了.F+CH3Cl反应中自由基攫氢过程和偶合反应过程共存的反应历程. 这一结论对红外激光诱导一碳卤代宾化学反应机理研究有重要参考意义. 相似文献
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全氟碘代烷R~FI[R~F=CF~3(CF~2)~5(1a);H(CF~2)~4(1b);H(CF~2)~8(1c);Cl(CF~2)~6(1d);Cl(CF~2)~8(1e)Cl(CF~2)~8(1f);;NaO~3S(CF~2)~20(CF~2)~2(1g);NaO~3S(CF~2)~2O(CF~2)~4(1h)]及α,ω-二碘化物I(CF~2)~nI[n=4(1i);n=6(1j)]与Ce^4^+-亚硫酸氢钠于70℃左右、pH3~4的溶液中反应,形成相应的全氟烷基亚磺酸盐,产率70~85%。全氟氯代烷和全氟溴代烷在同样条件下未能发生反应。 相似文献
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