排序方式: 共有1016条查询结果,搜索用时 15 毫秒
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白色的[Bu^tSAg]nPPh3溶于CS2中, 析出桔黄色晶体. 经X射线单晶结构分析其结构为(PPh3)2Ag(S2CSBu^t). 发现了一个CS2在Ag-S键中的插入反应. 此反应为可逆反应, 晶体在120-130℃失去CS2. 晶体属三斜晶系, 空间群P1,a=10.571(1), b=13.638(3), c=14.391(3)A, α=88.75(2), β=72.84(1), γ=80.58(1)°, V=1954.9A^3, Dc=1.36g/cm^3, Dm=1.36g/cm^3, Z=2. 3572个衍射点参与修正, R=0.045, Rw=0.043, Ag原子以变形四面体与硫代黄原酸配体Bu^tS-CS2的两个S原子及两个PPh3的P原子配位. 插入反应形成的CS3基团基本上共面, 其C-S键长比CS2中的键长明显加长, 而比单键的C-S键长要短, 并在红外光谱上出现特征吸收峰. 相似文献
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THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT 总被引:2,自引:0,他引:2
Ai-minLi Hai-suoWu Quan-xingZhang Gen-chengZhang ChaoLong Zheng-haoFei Fu-qiangLiu Jin-longChen 《高分子科学》2004,(3):259-267
Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p-nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate. 相似文献
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本文研究了在Pd(PPh3)2Cl2(1)催化下的三正丁基-2-呋喃基锡(6a), 三正丁基-2-噻吩基锡(6a), 三正丁基-2-(N-甲基)吡咯基锡(6c)和菊酰氯(5), 肉桂酰氯(7)的交联反应。发现除了三正丁基-2-(N-甲基)吡咯与5的不寻常反应得到2, 5-二取代的吡咯衍生物外, 其余反应皆以70~87%的产率得到交叉偶联产物。本文同时还报道了钯催化下有机锡试剂与取代卤代芳烃反应, 高收率地得到了不对称的杂环基芳烃和双杂环化合物。在合成的交联产物中, 化合物2, 8, 9, 15, 16与17均为新化合物。 相似文献
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合成了分子式为[Ln~2(phen)~2L],phen=C~1~2H~8N~2[ALn=Nd,L=(CH~3COO)~4(ONO~2)~2,BLn=Sm,L=(C~6H~5COO)~6,CLn=Eu,L=(C~6H~5COO)~6]3种同双核配合物。用X射线四圆衍射仪测定了3种化合物的结构。在化合物A分子中,2个Nd(III)原子由4个CH~3COO^-基团桥联,以phen和ONO~2^-为端基,构成了一个具有C~2对称性的双核分子。配合物B和C具有完全相同的结构,它们是以4个苯甲酸根为桥,2个phen和2个C~6H~5COO^-为端基的中心对称双核分子,其中6个苯甲酸根的成键状态可分为3种状况。在3种化合物中,每个Ln均为9配位,呈不规则多面体。Ln-Ln距离,A为0.397nm,B和C均为0.405nm。测定了各配合物的变温磁化率,通过对磁性质研究,发现化合物A在低温下具有反铁磁物质行为,并由理论拟合,求得了磁参数g,J值。 相似文献
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苯并-15-冠-5-四溴合铟(III)酸钾,KInBr~4(C~14H~20O~5)~2,晶体属单斜晶系,空间群为C~2h^5-P2~1/n,晶胞参数a=14.402(3),b=15.082(3),c=17.262(5)A,β=93.42(2),Z=4.非氢原子的位置由Patterson函数及Fourier合成法找出,经全矩阵最小二乘法修正R=0.057.结构分析表明K^+和两个苯并-15-冠-5(B-15-C-5)分子直接配位,对阴离子为InBr~4^-,具有四面体构型.InBr~4^-与配阳离子K(B-15-C-5)~2^+依靠静电引力结合为离子对.由此说明,In(III)在过量KBr存在下可以被B-15-C-5定量地萃取至有机相中. 相似文献