Kudo Yoshihiro, Katsuta Shoichi, Takeda Yasuyuki
Graduate School of Science, Chiba University, Japan.
Anal Sci. 2009 Apr;25(4):563-6. doi: 10.2116/analsci.25.563.
Cohesive energy densities (C(w,MLA)/J cm(-3)) for ion-pair complexes (MLA: M(+) = Li(+) to Cs+; w: water) with six crown ethers (L), such as 18-crown-6 ether (18C6), benzo-18C6, and dibenzo-24-crown-8 one, and A(-) = picrate were calculated at 298 K by a procedure that uses either (i) an equation rearranged from that underlying log K(D,MLA)-vs.-log K(D,L) plots or (ii) intercepts of their plots and from both procedures. Here, K(D,MLA) and K(D,L) denote the distribution constants of MLA and L from w into a diluent, respectively. As additional MLA, Na(18C6)(2,4-dinitrophenolate) and Na(18C6)(2,6-dinitrophenolate) were employed for the present C(w,MLA) calculation. The C(w,MLA) values calculated from the two procedures agreed well, and they were proportional to the log(K(D,MLA))(-1) values. From the log K(D,MLA) values for dinitrophenolates and previously-reported values for Na(18C6)A, the hydrophobic property of some pairing anions, A(-), was ordered as F(3)CCO(2)(-) < ReO(4)(-) < MnO(4)(-) < 2,4-dinitrophenolate < 2,6-dinitrophenolate < picrate, and then discussed based on a relation with the log K(ex) values, where K(ex) shows the extraction constant (mol(-2) dm(6) unit) for Na(18C6)A into 1,2-dichloroethane.
在298 K下，通过以下两种方法计算了六种冠醚（L）（如18-冠-6醚（18C6）、苯并-18C6和二苯并-24-冠-8）与苦味酸盐（A(-)）形成的离子对配合物（MLA：M(+) = Li(+)至Cs+；w：水）的内聚能密度（C(w,MLA)/J cm(-3)）：（i）从log K(D,MLA)对log K(D,L)图的基础方程重新排列得到的方程；（ii）它们的图的截距，以及两种方法的结果。这里，K(D,MLA)和K(D,L)分别表示MLA和L从水到稀释剂中的分配常数。作为额外的MLA，Na(18C6)(2,4-二硝基苯酚盐)和Na(18C6)(2,6-二硝基苯酚盐)用于本次C(w,MLA)计算。由这两种方法计算得到的C(w,MLA)值吻合良好，且与log(K(D,MLA))(-1)值成正比。根据二硝基苯酚盐的log K(D,MLA)值和先前报道的Na(18C6)A的值，一些配对阴离子A(-)的疏水性质顺序为F(3)CCO(2)(-) < ReO(4)(-) < MnO(4)(-) < 二硝基苯酚盐 < 2,6-二硝基苯酚盐 < 苦味酸盐，然后基于与log K(ex)值的关系进行了讨论，其中K(ex)表示Na(18C6)A进入1,2-二氯乙烷的萃取常数（mol(-2) dm(6)单位）。
