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用自由基溶液降合方法制备一系列苯乙烯-丙烯酸甲酯线型共聚物,用核磁共振测定了苯基在共聚物中的百分比,在该共聚物的四氢呋喃溶液中,用三氟乙酸汞在共聚物的苯环上进行亲电取代反应,得到可溶性汞化共聚物,由于这类泵化共的可溶于四氢呋喃,二氯甲烷等溶剂,用重沉淀法多次提纯,得到了纯度很高,溶解性较好的含重金属二价汞的共聚物,用红外光谱仪测定共聚物上的汞基团,用原子吸收定量测试共聚中的汞的百分聚代率,结果表明  相似文献   
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A simple new protocol for the high yielding Suzuki-Miyaura cross-couplings of aryl chlorides with aryl boronic acids using a palladium/imidazolium salt catalytic system is presented. The first examples of a palladium/imidazolium salt protocol for sp3-sp3 Suzuki-Miyaura couplings of alkyl halides are also disclosed.  相似文献   
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The palladium catalysed coupling of aryl chlorides and amines can be readily achieved with short reaction times when carried out at high temperatures under thermal or microwave conditions. These coupling protocols are successful using two co-ordinate palladium-N-heterocyclic carbene complexes, or imidazolium salt protocols.  相似文献   
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The novel complex cis‐[(ITMe)2Pd(SiMe3)2 (ITMe=1,3,4,5‐tetramethylimidazol‐2‐ylidene) has been synthesized by mild oxidative cleavage of Me3SiSiMe3 using [(ITMe)2Pd0]. The use of this complex as precatalyst for the cis‐bis(silyl)ation of alkynes using unactivated disilanes is reported.  相似文献   
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Cocondensation of cycloheptatriene with zirconium or hafnium vapours gives, after vacuum pyrolysis of the reaction mixture the diamagnetic d2 compounds [m(η-C7H7)(η-C7H9)].  相似文献   
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We describe in this paper the lithium insertion/extraction behavior of a new NASICON type Li2Co2(MoO4)3 at a low potential and explored the possibility of considering this new oxyanion material as anode for lithium-ion batteries for the first time. Li2Co2(MoO4)3 was synthesized by a soft-combustion glycine-nitrate low temperature protocol. Test cells were assembled using composite Li2Co2(MoO4)3 as the negative electrode material and a thin lithium foil as the positive electrode material separated by a microporous polypropylene (Celgard® membrane) soaked in aprotic organic electrolyte (1 M LiPF6 in EC/DMC). Electrochemical discharge down to 0.001 V from OCV (~3.5 V) revealed that about 35 Li+ could possibly be inserted into Li2Co2(MoO4)3 during the first discharge (reduction) corresponding to a specific capacity amounting to 1,500 mAh g?1. This is roughly fourfold higher compared to that of frequently used graphite electrodes. However, about 24 Li+ could be extracted during the first charge. It is interesting to note that the same amount of Li+ could be inserted during the second Li+ insertion process (second cycle discharge) giving rise to a second discharge capacity of 1,070 mAh g?1. It was also observed that a major portion of lithium intake occurs below 1.0 V vs Li/Li+, which is typical of anodes being used in lithium-ion batteries.  相似文献   
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