Host-guest complexation. 45. A highly preorganized chromogenic spherand indicator system specific for sodium and lithium ions
作者:Donald J. Cram、Richard A. Carmack、Roger C. Helgeson
DOI:10.1021/ja00210a043
日期:1988.1
The synthesis and chromogenic properties of 1 as a sodium and lithium ion selective indicator system are described. The pK/sub a/ values of 1 in the absence and presence of various metal ions were measured in 80% dioxane-20% water (v/v). Observed values were as follows: Li/sup +/, 5.9; Na/sup +/, 6.9; K/sup +/, 12.7; Ca/sup 2 +/, 12.8; Mg/sup 2 +/, 13.2; 1,5-diazabicyclo(4.3.0)non-5-ene (DBN), 13.0
描述了 1 作为钠和锂离子选择性指示剂系统的合成和显色特性。在 80% 二恶烷-20% 水 (v/v) 中测量了在不存在和存在各种金属离子的情况下 pK/sub a/ 值为 1。观察值如下:Li/sup+/-,5.9;Na/sup +/,6.9;K/sup +/,12.7;Ca/sup 2 +/,12.8;Mg/sup 2 +/,13.2;1,5-二氮杂双环(4.3.0)non-5-ene (DBN), 13.0. 非复合模型系统21在相同介质中给出10.8的pK/sub a/。Spherand 1 是黄色的(λ/sub max/396 nm;epsilon/sub max/17,500 L/(mol x cm)),而 spheraplexes 1/sup -/ x Li/sup +/(λ/sub max/ 586 nm, epsilon/sub max/ 35,500 L/(mol X cm)),和