L M log KD,A log Kex ()a log Kex± log Kn,NB ()b
n = 1

2

18C6 Ca -1.43 ± 0.03 9.82 ± 0.02 (5.3×10-3) 5.44 ± 0.07 5.43 ± 0.18c 5.9 [4.7]d 4.38 ± 0.08 (8.9×10-4)
Sr -0.98 ± 0.07 11.44 ± 0.03 (3.1×10-3) 6.92 ± 0.12 6.91± 0.13c 5.3 [4.6]d 4.52±0.12 (4.8×10-4)
Ba -0.69 ± 0.04 10.75 ± 0.08 (4.5×10-3) 7.35 ± 0.11 7.44 ± 0.33c 4.9 [3.4]d 3.41 ± 0.14 (5.9×10-4)
B18C6 Ca -1.92 ± 0.04 7.35 ± 0.08 (3.6×10-3) 2.71 ± 0.10 2.80 ± 0.29c 5.0 [5.5]d 4.64 ± 0.13 (6.9×10-4)
Sr -1.34 ± 0.04 9.41 ± 0.02 (4.0×10-3) 4.34 ± 0.08 4.33 ± 0.13c 4.7 [4.6]d 5.07 ± 0.08 (2.3×10-4)
Ba -1.17 ± 0.02 9.51 ± 0.02 (4.7×10-3) 5.01 ± 0.11 5.08 ± 0.42c 4.1 [4.2]d 4.50 ± 0.11 (2.1×10-4)
aAverage values of I in the w phase. bAverage values of INB in the NB phase. cLogarithms of average values calculated from each values of Kex± and their propagation errors simultaneously-calculated. dNumber, h, of water molecules coextracted with ML2+ into the NB phase. See ref. [17]
Table 3: Fundamental equilibrium constants for the extraction of alkaline-earth metal picrates by L into nitrobenzene at 298 K.