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合成和表征了三个新的冠醚化双西佛碱4',5'-双(2-羟基苯亚甲基亚氨基)苯并-12-冠-4(L^1H2),4',5'-双(5-氯-2-羟基苯亚甲基亚氨基)苯并-12-冠-4(L^1H2)和4',5'-双(5-溴-2-羟基苯亚甲基亚氨基)苯并-12-冠-4(L^3H2)以及它们的钴配合物。在吡啶溶液中和不同温度下,测定了配合物的饱和吸氧量,求出了它们的氧加合常数和热力学参数△H°,△S°,并以这些配合物为催化剂,活化分子氧氧化环已烯制备环已烯酮,通过与未冠醚化的类似物作比较,讨论了冠醚环的引入对配合物与氧分子加合性能以及催化氧化性能的影响。 相似文献
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本文用3,5-二叔丁基二苯并-14-冠-4双羟基冠醚的顺式和反式异构体分别与溴乙酸、3-溴丙酸及氯代乙酰氯反应,制备了4个双羧酸冠醚及2个双氯代乙酸酯冠醚衍生物。此外,通过1,1′-(邻苯)-双-(2,3-环氧丙基)醚与2,2′-联苯二酚反应,合成了联苯型苯并14-冠-4双羟基冠醚,分离了顺、反异构体,并使之与溴乙酸反应,制备了相应的双羧酸冠醚衍生物。10个新化合物的结构均经IR、1H NMR、MS和元素分析确定。 相似文献
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稀土冠醚配合物的研究XV. 稀土硝酸盐与臂型冠醚配合物的合成 和性质研究 总被引:4,自引:0,他引:4
本工作以6-羟基-2,3,9,10-二苯并-1,4,8,11,14-五氧杂-环十六-2,9-二烯(1)及其衍生物(2,3和4)为配体,在乙腈中合成了十八种新的稀土硝酸盐配合物。其中羧酸冠醚4与稀土硝酸盐[Ln(NO~3)~3]分别形成2:1型(Ln=La,Ce,Pr,Nd)、4:3型(Ln=Sm)和3:4型(Ln=Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)配合物;冠醚1与La(NO~3)~3形成1:1型配合物;冠醚2,3与La(NO~3)~3均形成2:1型配合物。对所得配合物进行了元素分析、紫外光谱、红外光谱、^1H核磁共振、X射线光电子能谱等性质研究。对臂型冠醚中边臂的配位作用进行了初步讨论。 相似文献
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本工作以6-羟基-2,3,9,10-二苯并-1,4,8,11,14-五氧杂-环十六-2,9-二烯(1)及其衍生物(2,3和4)为配体,在乙腈中合成了十八种新的稀土硝酸盐配合物.其中羧酸冠醚4与稀土硝酸盐[Ln(NO_3)_3]分别形成2∶1型(Ln=La,Ce,Pr,Nd)、4∶3型(Ln=Sm)和3∶4型(Ln=Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y)配合物;冠醚1与La(NO_3)_3形成1∶1型配合物;冠醚2,3与La(NO_3)_3均形成2∶1型配合物.对所得配合物进行了元素分析、紫外光谱、红外光谱、~1H核磁共振、X射线光电子能谱等性质研究.对臂型冠醚中边臂的配位作用进行了初步讨论. 相似文献
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本文报道以大环中性配体作为大块液膜载体时,冠醚结构对金属离子的传质选择性,以及迁移速度与配合物稳定常数之间的关系。实验结果表明,在一定的配合物稳定常数范围,其稳定常数越高,迁移速度也越快。对于4-取代苯并-15-冠-5类型的冠醚与Na~+的配合物,其配合物的稳定常数顺序与取代基的给电子或吸电子效应的强弱一致,而迁移速度与稳定常数的大小顺序一致。在影响着冠醚醚氧碱度的取代基效应的Hammett常数(δm+δ_P)同配合物稳定常数logk及离子迁移通量logJ之间存在着线性关系。对于其空腔直径与N_a~+相匹配的苯并-15-冠-5及空腔直径与K~+相匹配的苯并-18冠-6,当冠醚中的一个或两个1,2-亚乙基被1,3-亚丙基所代替而变成苯并-17-冠-5及苯并-19-冠-6时,其配合物的稳定常数减小,迁移速度也相应减小。 相似文献
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冠醚化单和双Schiff碱的合成及其钴(II)配合物的氧加合性能 总被引:13,自引:0,他引:13
由苯并-15-冠-5经硝化、还原和缩合反应,制备了4'-(2-羟基苯亚甲基亚氨基)苯并-15-冠-5(L^1H)和4',5'-双(2-羟基苯亚甲基亚氨基)苯并-15-冠-5(L^4H~2)以及它们的取代衍生物L^2H和L^5H~2。在不同温度和不同轴配体存在下,测定了它们的钴(II)配合物的氧合常数和ΔHⅲ,ΔSⅲ,并与未冠醚化的类似物CoL~2^3和CoL^6比较,讨论了配体结构和轴配体碱性对配合物的氧分子加合性能的影响。 相似文献
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Three selena-crown-4 derivatives have been prepared and their cation binding abilities and selectivities with alkali and heavy metal ions have been evaluated by solvent extraction of aqueous metal picrates to show the highest Ag extractability for novel benzo-selena-14-crown-4 (2,3-benzo-7,12-diselena-1, 4-dioxacyclotetradecane-2-ene) over any other crown ethers. 相似文献
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用^2^3Na NMR研究了15-冠-5(15C5), 2,3-苯并-15-冠-5(B-15C5), 2,3-苯并-6-甲基-15-冠-5(BCl-15C5), 2,3-苯并-8,12-二甲基-15-冠-5(BC2-15C5)在丙酮中与Na^+的配位反应, 由此探索甲基的影响, 实验结果表明, 当在金属盐溶液中加入冠醚, 配体为15C5时, 体系表观化学位移移至低场, 配体为B-15C5, BC1-15C5, BC2-15C5时, 体系在表观化学位移移至高场, 后者与苯并-18-冠-6及其甲基衍生物不同, 这是由于苯环在空间排布不同所致, 用Newton-Raphson法和描坑法(Pit-mapping)拟合实验数据, 发现BC1-15C5和BC2-15C5除形成NaL^+和NaL2^+外还有不稳定的Na3L2^3^+形成。本文对形成过程和生成NaL^+反应的平衡常数lgK11与甲基数的关系亦作了讨论, lgK11与甲基数目n近似成直线关系, 可用下式表示: lgK11=3.50-0.80n, n=0,1,2。 相似文献
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Synthesis of Double-Armed Benzo-15-crown-5 and Their Complexation Thermodynamics with Alkali Cations
Yu Liu Jian-Rong Han Zhong-Yu Duan Heng-Yi Zhang 《Journal of inclusion phenomena and macrocyclic chemistry》2005,52(3):229-235
A series of double-armed benzo-15-crown-5 lariats (3–8) have been synthesized by the reaction of 4′, 5′-bis(bromomethyl)-benzo-15-crown-5 (2) with 4-hydroxybenzaldehyde, phenol, 4-chlorophenol, 4-methoxyphenol, 2-hydroxybenzaldehyde, and 4-acetamidophenol in 43 ~ 82% yields, respectively. The complex stability constants (K
S) and thermodynamic parameters for the stoichiometric 1:1 and/or 1:2 complexes of benzo-15-crown-5 1 and double-armed crown ethers 3–8 with alkali cations (Na+, K+, Rb+) have been determined in methanol–water (V/V=8:2) at 25 °C by means of microcalorimetric titrations. As compared with the parent benzo-15-crown-5 1, double-armed crown ethers 3–8 show unremarkable changes in the complex stability constants upon complexation with Na+, but present significantly enhanced binding ability toward cations larger than the crown cavity by the secondly sandwich complexation. Thermodynamically, the sandwich complexations of crown ethers 3-8 with cations are mostly enthalpy-driven processes accompanied with a moderate entropy loss. The binding ability and selectivity of cations by the double-armed crown ethers are discussed from the viewpoints of the electron density, additional binding site, softness, spatial arrangement, and especially the cooperative binding of two crown ether molecules toward one metal ion. 相似文献
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含嘧啶环的双冠醚(Ⅱ) 总被引:2,自引:0,他引:2
由4,6-二氯-5-硝基嘧啶、2,4-二氯-5-硝基-6-甲基嘧啶分别与4′-氨基苯并冠醚反应合成了6种以嘧啶环为桥链的新双冠醚,其中分别含有苯并-12-冠-4(Al,Bl)、苯并-15-冠-5(A2,B2)和苯并-18-冠-6(A3,B3)单元。用这些双冠 氯仿溶液绎碱金属苦味酸盐水溶液进行了萃取,计算了萃取平衡常数Kc。结果表明双冠醚(A1,B1)、(A2,B2)和(A3,B3)分别对钠、钾和铯具有较高的萃取能力,其选择性显著优于相应的单冠醚。 相似文献
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Bhattacharya S Sharma A Nayak SK Mukherjee AK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(13):2841-2848
Vertical ionisation potentials (I(v)D) of a number of crown ethers, viz. dibenzo-30-crown-10 (Crown 1), benzo-15-crown-5 (Crown 2), dibenzo-24-crown-8 (Crown 3), dicyclohexano-24-crown-8 (Crown 4) and 4'-nitrobenzo-15-crown-5 (Crown 5) are being reported for the first time from a study of EDA interaction of these crown ethers with a number of electron acceptors like C60, C70, o-chloranil, p-chloranil, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and pyromellitic diimide (PMD). The study has been carried out in CCl4 medium by electronic absorption spectroscopy. Charge transfer (CT) absorption bands in the 360-900 nm range have been found in each case (excepting the 60 fullerene-Crown 4 system). The vertical ionisation potentials (I(v)D) of all the crown ethers thus determined show a good correlation with those calculated by the semiempirical AM1 method. Of the six acceptors under study the vertical electron affinity of PMD was not found in the literature. This has also been determined from an analysis of the present h(nu)(CT) data. 相似文献
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Bronislaw P. Czech Wolodymyr Zazulak Anand Kumar N. Kent Dalley Jiang Weiming Richard A. Bartsch 《Journal of heterocyclic chemistry》1991,28(5):1387-1394
A series of nine, new benzo-13-crown-4 compounds which bear one or two substituents on the three-carbon bridge has been prepared in good yields by cesium fluoride-assisted cyclization reactions of catechol with ditosylates of the appropriate glycols. The solid state structure of 9,9-dibenzyl-2,3-benzo-13-crown-4 is determined and compared with the reported structure for the unsubstituted crown ether. 相似文献
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