Constantes de stabilite et vitesses deformation et de dissociation des cryptates alcalinoterreux avec (2,1,1), (2,2,1), (2,2,2), (2 B ,2,2) et (2 B ,2 乙 ,2)
One- and two-step metal ion templated syntheses of the cryptands
作者:Krzysztof E Krakowiak、Jerald S Bradshaw、Xiaolan Kou、N.Kent Dalley
DOI:10.1016/0040-4020(94)01051-z
日期:1995.2
New cryptands [3.2.1], [4.2.1] and [4.2.2] were prepared in good yields by treating the appropriate diazacrown with the ditosylate esters of triethylene, tetraethylene or pentaethylene glycol as required. Treatment of 4,10-diaza-15-crown-5 with α,α′-dibromo-m-xylene gave a mixture of the cryptand (1:1 cyclization) and the tricyclic bisdiaza-15-crown-5 connected by two m-xylylene units (2:2 cyclization)
通过根据需要用三亚乙基,四亚乙基或五亚乙基二醇的二甲苯磺酸酯处理适当的二氮杂皇冠,以高收率制备新的穴状配体[3.2.1],[4.2.1]和[4.2.2]。的治疗-4,10-二氮杂-15-冠-5与α,α '-dibromo-米二甲苯,得到穴状配体的混合物:和三环bisdiaza-15-冠-5由两个连接(11环化)米当将K 2 CO 3用作碱时,生成亚二甲苯基单元(环化率为2:2)。当使用Li 2 CO 3时,相同的反应仅给出1∶1的环化。m的1 H NMR光谱含亚二甲苯的穴状配体在δ8.85处出现一个峰,这表明苯位置2上的质子靠近diaza-15-crown-5腔。该化合物的X射线晶体结构表明确实如此。在由3,6,9-三氧杂-1,11-二碘十二烷及其二胺类似物制备[3.3.3]时,也观察到金属离子模板作用。K 2 CO 3仅观察到[3.3.3] 。当使用Cs 2 CO 3时,主要分离出双(氮
Crystal structure of the cryptand [3.33] - potassium iodide complex: A large coordination number for potassium ion
作者:N.Kent Dalley、Krzysztof E. Krakowiak、Jerald S. Bradshaw、Mark M. England、Xiaolan Kou、Reed M. Izati
DOI:10.1016/s0040-4020(01)86988-x
日期:1994.2
9-trioxaundecane in acetonitrile using potassium carbonate as the base. An X-ray crystal study of the KI-[3.3.3] complex shows that all cryptand donor atoms are directed towards the encapsulated K+. The K+ ion is not midway between the two nitrogen atoms, but is 3.15Å from one nitrogen and 3.37Å from the other. The X-ray structure strongly suggests that potassium is coordinated by eleven donor atoms